,*, 鲁芮伶, 朱辰, 崔二乾, 杜莹, 黄昆, 孙宝玉华东师范大学生态与环境科学学院, 上海 200241Response and adaptation of terrestrial ecosystem processes to climate warming
Jian-Yang XIA,*, Rui-Ling LU, Chen ZHU, Er-Qian CUI, Ying DU, Kun HUANG, Bao-Yu SUNSchool of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China通讯作者: * E-mail:jyxia@des.ecnu.edu.cn
编委: 陈保冬
责任编辑: 赵 航
收稿日期:2019-11-22接受日期:2020-02-2网络出版日期:2020-05-20
| 基金资助: |
Received:2019-11-22Accepted:2020-02-2Online:2020-05-20
| Fund supported: |
摘要
陆地生态系统包含一系列时空连续、尺度多元且互相联系的生态学过程。由于大部分生态学过程都受到温度调控, 因此气候变暖会对全球陆地生态系统产生深远的影响。近年来, 全球变化生态学的基本科学问题之一是陆地生态系统的关键过程如何响应与适应全球气候变暖。围绕该问题, 该文梳理了近年来的研究进展, 重点关注植物生理生态过程、物候期、群落动态、生产力及其分配、凋落物与土壤有机质分解、养分循环等过程对温度升高的响应与适应机理。通过定量分析近20年来发表于主流期刊的相关论文, 展望了该领域的前沿方向, 包括物种性状对生态系统过程的预测能力, 生物地球化学循环的耦合过程, 极端高温与低温事件的响应与适应机理, 不对称气候变暖的影响机理和基于过程的生态系统模拟预测等。基于这些研究进展, 该文建议进一步研究陆地生态系统如何适应气候变暖, 更多关注我国的特色生态系统类型, 并整合实验、观测或模型等研究手段开展跨尺度的合作研究。
关键词：
Abstract
Terrestrial ecosystems are characterized by a series of spatiotemporally continuous, multiple scaled, and mutually connected processes. Since most of these ecological processes are regulated by temperature, climate warming will profoundly impact terrestrial ecosystems at global scale. Recently, how key processes in terrestrial ecosystems respond and/or adapt to climate warming has become a fundamental question in global change ecology. Here, we reviewed the recent research progress related to such question. This review focuses on key ecosystem processes, such as plant ecophysiological processes, phenology, community dynamics, productivity and carbon allocation, decomposition of litter and soil organic carbon, nutrient cycling, and carbon-nitrogen coupling. Based on a literature review, we propose perspectives for future research to tackle fundamental questions, such as the predictability of plant traits on ecosystem processes, coupling between biogeochemical cycles, mechanisms driving ecosystem responses to extreme climate and asymmetric warming, and ecological forecasting with models. We finally suggest more research efforts on warming adaptation rather than response on China’s specific ecosystems, and on the integration of experiments, observations, and models for coordinating studies across scales.
Keywords：
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引用本文
夏建阳, 鲁芮伶, 朱辰, 崔二乾, 杜莹, 黄昆, 孙宝玉. 陆地生态系统过程对气候变暖的响应与适应. 植物生态学报, 2020, 44(5): 494-514. DOI: 10.17521/cjpe.2019.0323
XIA Jian-Yang, LU Rui-Ling, ZHU Chen, CUI Er-Qian, DU Ying, HUANG Kun, SUN Bao-Yu.
关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪。古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(Morton, 1981)。自18世纪以来, 植被分布格局与气候条件之间的关系逐渐成为生态学研究的热点领域。大量的研究结果表明, 温度与降水条件的结合可以解释陆地植被类型及其关键功能在全球空间尺度的分布格局。例如, Holdridge (1947)基于温度与水分条件将全球划分为38个生命区系, 并被Emanuel等(1985)应用于全球植被响应未来气候变化的预测。Lieth (1975)基于温度与降水条件推算了生态系统初级生产力的全球分布, 并将该方法命名为迈阿密模型。自工业革命以来, 地球表面温度的增加幅度约为0.87 ℃, 预计在2030-2052年间达到1.5 ℃ (IPCC, 2018)。全球气候变暖及其伴随产生的降水格局改变、冰川和冻土消融、海平面上升等气候与环境变化对陆地生态系统的结构与功能产生了深远的影响。因此, 陆地生态系统如何响应与适应全球温度的迅速升高在近年来成为了生态学领域的热点和难点问题。
自20世纪60年代以来, 国际科学联合会(ICSU)陆续启动了国际生物学计划(IBP)与国际地圈生物圈计划(IGBP), 极大地推动了陆地生态系统响应气候变化的研究。1988年成立的政府间气候变化委员会(IPCC), 陆续出版了多种形式的气候变化评估报告。其中, 第三次IPCC报告(IPCC, 2001)首次将碳循环作为重要评估对象, 从而推动了近年来陆地生态系统过程响应与适应气候变化相关研究的蓬勃发展。这些研究逐渐呈现出多时空尺度、多学科交叉和多种研究方法融合等特点, 并且关注的生态学过程也日趋丰富。这些生态学过程不仅发生于有机体的不同组织层次, 并且涵盖了各种时间尺度。例如, 近来颇受关注的陆地生态系统过程包括分秒尺度的植物酶活性和电子传递速率, 小时与日尺度的植物光合作用及土壤呼吸过程, 季节尺度的植物物候过程(包括展叶、开花、结果与落叶等), 季节与年尺度的植物群落动态和生态系统生产力变异, 年际或年代际尺度的植物物种分布与迁移, 更长时间尺度的土壤有机质稳定与分解过程等方面。因此, 针对国际上研究进展较快的生态系统过程, 开展综述性研究, 有助于梳理该领域近期的重要进展与存在的主要问题。
针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(傅伯杰等, 2005; 徐小峰等, 2007; 方精云等, 2018; 朴世龙等, 2019)。本文在这些综述研究的基础上, 重点关注陆地生态系统的关键过程如何响应与适应全球温度升高, 并总结该领域近年来的研究进展。同时, 本文系统地调研了自2000年以来发表于Science、Nature、PNAS与Global Change Biology 4本优秀期刊的所有相关论文, 定量分析了该领域的发展动态, 并以此展望未来的研究方向。因篇幅所限, 本文主要围绕图1所示的关键生态系统过程展开综述, 以期激发国内相关领域的进一步讨论与研究。
图1
新窗口打开|下载原图ZIP|生成PPT图1气候变暖对陆地生态系统关键过程的影响。①氮矿化过程; ②氮固持过程; ③氮吸收过程; ④反硝化过程; ⑤固氮过程; ⑥氮淋溶与径流过程。绿色虚线方框代表各关键过程, 蓝色方框代表各碳氮储存库, 虚线箭头表示碳氮耦合过程。
Fig. 1Impact of climate warming on key processes in terrestrial ecosystems. ① N mineralization; ② N immobilization; ③ N uptake; ④ N denitrification; ⑤ N fixation; ⑥ N leaching and running off. GPP, gross primary productivity; NPP, net primary productivity. Green dashed boxes indicate key processes, blue boxes show C and N storage pools, and dashed arrows represent the carbon-nitrogen coupling processes.
1 陆地生态系统关键过程对气候变暖的响应与适应
1.1 植物生理生态过程
在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容。总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线。植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(Berry & Bj?rkman, 1980; Yamori et al., 2014)。近年来, 许多文献报道了高温对光合作用的限制作用, 并提出了不同的假说。第一个假说认为高温使Rubisco活化酶的热稳定性下降, 并伴随大量失活现象, 从而导致叶片光合速率下降(Crafts-Brandner & Salvucci, 2000; Yamori & von Caemmerer, 2009; Busch & Sage, 2017)。第二个假说认为高温限制了电子传递速率, 从而降低Rubisco活化酶的活性与光合速率(Sharkey, 2005; Sage & Kubien, 2007)。呼吸速率随着温度的上升总体上呈现指数增高的趋势(Hofstra & Hesketh, 1969; Clark & Menary, 1980; Heskel et al., 2016)。因此, 温度升高对植物叶片水平碳收支的影响取决于光合与呼吸作用二者对温度变化的响应差异。植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制。该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(Berry & Bj?rkman, 1980; Sage & Kubien, 2007; Smith & Dukes, 2013; Way & Yamori, 2014)。其程度在不同植物物种之间存在明显差异(Way & Yamori, 2014; Smith & Dukes, 2017)。近年来,光合最适温度随温度升高而上移的现象也在生态系统水平得到证实(Niu et al., 2012)。最新的大尺度分析研究表明全球生态系统尺度总初级生产力的最适温度大约为(23 ± 6) ℃ (Huang et al., 2019)。相比于光合作用, 植物的呼吸作用具有更高的最适温度区间。然而, 呼吸作用也会对持续的温度上升产生顺应性或适应性(Atkin & Tjoelker, 2003; Atkin et al., 2005), 并产生温度敏感性下降的现象(Atkin & Tjoelker, 2003; Slot & Kitajima, 2015)。目前关于植物呼吸作用对升温产生顺应或适应性的原因仍存在争议, 包括叶片氮含量降低(Tjoelker et al., 1999; Crous et al., 2017), 线粒体的密度或结构发生改变(Armstrong et al., 2006)与呼吸底物和腺苷酸的限制(Atkin & Tjoelker, 2003)等。需要指出的是, 目前该方向的许多研究论文在报道结果时未严格定义顺应性与适应性, 因此难以梳理二者在已有研究结果中的异同。虽然植物的光合与呼吸作用对增温的响应存在较大差异, 但是二者的比例(即呼吸速率/净光合速率)在一定温度范围内可以达到稳态(Dusenge et al., 2019)。具体而言, 随着温度逐渐升高, 不断累积的光合产物为呼吸作用的升高提供了底物; 当光合速率由于高温胁迫开始下降时, 植物的呼吸速率由于底物不足无法继续上升甚至开始下降, 最终使二者达到平衡(Slot & Kitajima, 2015; Dusenge et al., 2019)。因此, 植物光合与呼吸作用如何协同地响应气温升高是探究陆地生态系统对气候变化反馈作用的关键问题。
1.2 植物物候
植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感。目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注。大量的地面和遥感观测数据表明气候变暖促使春季物候提前(Fitter & Fitter, 2002; Zheng et al., 2002; Menzel, 2003; Piao et al., 2015)。然而, 随着气温持续升高, 近年来的一些研究发现春季物候对温度响应的敏感性逐渐降低(Fu et al., 2015), 甚至发生逆转导致春季物候推迟(Fu et al., 2014)。另一方面, 春季物候的温度响应在空间变异上也出现一些新现象, 例如欧洲阿尔卑斯山脉的植物春季物候在海拔梯度上呈现出趋同的规律(Vitasse et al., 2018)。这些新发现挑战了生态学中的一些经典规律, 例如“霍普金斯法则” (Hopkins bioclimatic law)(Hopkins, 1920)认为植物春季物候随纬度与海拔上升呈现稳步推迟的变化规律。相比于春季物候, 温度升高对秋季物候的延迟作用不明显, 并且其驱动因子仍不十分清楚(Menzel et al., 2006; Liu et al., 2016)。基于大尺度资料的研究发现增温对春季和秋季物候的影响最终都导致了植物生长季的延长(Parmesan, 2007; Piao et al., 2007), 但是对个体物种的观测却发现许多物种应对气候变暖时缩短了生命周期(Cleland et al., 2006; Sherry et al., 2007)或保持不变(Xia & Wan, 2013)。因此, 为了全面地理解植物个体与群落水平的物候响应差异, 未来的研究需要基于不同时空尺度水平的物候观测资料进行整合研究(Steltzer & Post, 2009)。近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(While & Uller, 2014; Ge et al., 2015; Thackeray et al., 2016)。有研究认为, 鸟类和昆虫等的物候过程主要受到短期温度变化的影响, 而植物物候的变化则更多受到长期气候变暖的驱动(Ovaskainen et al., 2013)。此外, 动物物候对气温升高的响应受到系统发育和个体体型的影响(Cohen et al., 2018)。近几十年来, 植物与动物之间物候同步性已经发生了变化(Kharouba et al., 2018)。然而, 目前我们对动植物物候过程对气候变暖的差异化响应及其对生态系统其他过程的影响仍然缺乏深入的认识。
1.3 植物群落动态
生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应。大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(Parmesan & Yohe, 2003; Pauli et al., 2012; Steinbauer et al., 2018), 从而导致新的物种组合(Wing et al., 2005; Bertrand et al., 2011)。例如, 气候变暖导致全球树线位置向更高的海拔和纬度推进(Harsch et al., 2009)。小尺度的控制实验数据能够排除其他因素的干扰, 因而为评估气候变化对群落的影响提供必要的机理解释。近年来的许多实验都发现增温能够显著改变群落的物种组成。例如, 在北美高草草原, 实验增温处理对C3和C4物种的生长产生了不同影响, 并使植物群落朝C4植物占优势的方向变化(Luo et al., 2009)。需要注意的是, 增温对该草地群落结构的改变在极湿润的年份最为显著(Shi et al., 2015)。在北半球苔原地区11个站点的增温实验发现, 温度上升增加了落叶灌木和禾本科植物的高度和盖度, 降低了苔藓和地衣的盖度和物种多样性, 从而迅速改变了植物群落结构(Walker et al., 2006)。在明尼苏达州北部沼泽进行的增温实验则发现, 酸性沼泽中灌木比禾本科物种更占优势, 而在碱性沼泽中禾本科物种比非禾本科草本植物更占优势(Weltzin et al., 2000)。实验增温虽然未改变我国青藏高原高山草甸生态系统的生产力, 但是显著地降低了植物物种之间的时间非同步性, 从而降低了生产力的稳定性(Ma et al., 2017)。以上研究结论的差异证明植物群落动态对气候变暖的响应与适应具有很高的复杂性。Smith等(2009)提出了一个“层级响应框架” (hierachical-response framework)试图解释植物群落响应气候变化的统一性机理。然而, 该框架主要关注草原生态系统模拟降水实验中出现的现象, 因此至今尚未得到普遍关注和应用。虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识。这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态。例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(Walker et al., 2006); 内蒙古半干旱草原通过土壤水分和种间相互作用来调节植物群落结构和组成对增温的响应(Yang et al., 2011)。在北方森林生态系统, 温度升高对树木生长的影响也显著依赖于土壤水分条件(Reich et al., 2018b)。气候变暖对土壤氮循环也存在显著影响, 尤其是普遍促进了氮矿化速率(Bai et al., 2013), 且该现象大多伴随着植物群落物种组成的改变(Wu et al., 2012)。由于氮对植物的增产效应存在显著的种间差异(Xia & Wan, 2008; Midolo et al., 2019), 因此可以推断氮循环的改变是调控植物群落响应气候变暖的重要机理。然而, 目前探讨该机理的实验性研究仍然较少(An et al., 2005), 大多只关注氮添加与增温处理对生态系统过程的交互效应(Xia et al., 2009, 2013; Wu et al., 2012; Xiong et al., 2018)。近来的许多研究表明, 菌根真菌有利于增强寄主植物对气候变暖的适应性, 因此在调控植物群落响应气候变暖的过程中扮演了重要的角色(Cowden et al., 2019)。总之, 植物群落结构与物种组成对气候变暖的响应是多个复杂过程综合作用的结果, 也是未来预测气候变化背景下植物群落动态的重要挑战。
1.4 生态系统生产力及其分配过程
气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(Quan et al., 2019)。在气候变暖下, 北半球中高纬度地区和青藏高原地区的植被呈现出光合作用增强和生长季延长的变化趋势, 进而促进生态系统生产力显著升高(Keeling et al., 1996; Myneni et al., 1997; Nemani et al., 2003; Xu et al., 2013; Zhu et al., 2016)。例如, 温度升高显著促进了北寒带地区(阿拉斯加西部, 北魁北克北部和西伯利亚东北部等)木本植物的生长(McManus et al., 2012)。全球变暖引发的北高纬度地区积雪和冻土融化加速了灌木在苔原地区的扩张(Myers-Smith et al., 2011)。与此同时, 中高纬度地区植被生长活动与温度的敏感性强度在近30年中呈现出明显下降趋势(Piao et al., 2014)。持续增温可能会对热带植被的生长产生负面影响。例如, 有研究表明温度升高会抑制叶片气体交换从而降低热带森林的植被生产力和生长速率(Clark et al., 2003)。另一方面, 温度持续升高所引发的干旱和热浪事件会显著抑制植被生长, 甚至导致全球大范围的树木死亡 (Allen et al., 2010, 2015)。例如, 2003年欧洲高温热浪抑制陆地植被对大气CO2的吸收(Ciais et al., 2005)。干旱胁迫甚至可以通过破坏热带雨林的植物水分吸收运输机制从而导致树木的死亡(Rowland et al., 2015; McDowell et al., 2018)。在气候变暖导致干旱和热浪事件剧增的背景下, 植被生长对于极端事件的响应和恢复是未来需要重点关注的方向。生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变。最近, Collalti和Prentice (2019)对NPP/GPP进行了系统地综述, 并认为该比值对温度变化的响应较小。这个结论也得到一项基于整树同位素标记实验(Drake et al., 2019)的支持。虽然大多数陆地生态系统模型中的NPP/GPP内部变异极小, 但是模型之间的数值差异很大(Xia et al., 2017)。此外, 生态系统净初级生产力分配到根系、茎干与叶片等组织器官的过程将对生态系统的结构与功能产生重要影响。总体而言, 温度升高在寒冷生态系统中会促进植物更多地向地上生长分配(Lin et al., 2010; Way & Oren, 2010)。然而需要指出的是, 自然生态系统中的净初级生产力分配过程难以被直接测定, 所以文献中大多报道的是生物量的分配比例。近年来, 许多关于生产力分配的研究开始关注非结构性碳水化合物的动态, 这是由于大量实验证据发现碳水化合物在调节植物适应极端气候变化方面具有重要意义(Doughty et al., 2015; Malhi et al., 2017; Du et al., 2020)。
1.5 凋落物与土壤有机质分解过程
植物凋落物在生态系统的物质循环过程中具有重要作用(图1)。长期以来, 气候条件被认为是植物凋落物分解速率的主要调控因子(Meentemeyer, 1978; Wall et al., 2008; Zhang et al., 2008; Gregorich et al., 2017), 因此气候变暖被认为将加速凋落物的分解过程。近年来, 有大量的野外生态学研究发现凋落物的功能性状或微生物群落是控制凋落物分解速率的首要因子(Bradford et al., 2014; Ward et al., 2015; Parker et al., 2018), 因此气候变暖不能从根本上改变植物凋落物的分解速率。事实上, Tenney和Waksman (1929)最早提出的假说认为凋落物分解速率受温度、湿度与凋落物质量三者共同调控。最近在美国黄石国家公园的一项研究表明, 除了气候与凋落物质量之外, 大型食草动物也是凋落物分解速率的重要影响因子(Penner & Frank, 2019)。因此, 生物与气候因子在不同生态系统中的相对重要性及其转换机制是目前该方向上比较重要的问题。土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(Knorr et al., 2005; Bond-Lamberty et al., 2018)。例如, Crowther等(2016)整合分析了49个野外增温实验中土壤有机碳库的变化, 发现土壤有机碳储量更大的生态系统丢失更多有机碳, 因此认为气候变暖将加剧大气CO2浓度上升。然而, 该研究结果随后受到了van Gestel等(2018)的挑战, 该研究整合分析了143个实验数据, 发现Crowther等(2016)报道的规律在更大的数据样本中没有出现。因此, 从生态学机理方面理解土壤有机碳分解的温度敏感性对预测生态系统对气候变暖的响应至关重要(Smith et al., 2008; Paustian et al., 2016)。已有的研究结果已经证实土壤底物质量和微生物活性是影响土壤有机碳温度敏感性的关键限制因素(Karhu et al., 2014; Moinet et al., 2018)。然而, 全球变暖背景下土壤底物质量如何变化, 以及微生物活性是否存在顺应或适应现象仍不清楚(Luo et al., 2001; Frey et al., 2013; Allison et al., 2018)。近年来, 分布于全球不同区域的野外模拟增温实验报道了一些新现象。例如, Melillo等(2017)在26年增温实验中观测到美国哈佛森林的土壤有机质分解速率对温度升高出现周期性响应节律, 并可被分为四个阶段。这些阶段包括土壤表层易分解有机质大量丢失、微生物群落重组、难分解有机质成为微生物主要碳基质与微生物群落再重组, 最终使难分解有机质在增温条件下加速分解。然而, 由于其他增温实验大多运行时间较短(Song et al., 2019), 因此该研究揭示的生态学机理仍有待于进一步验证。
1.6 元素循环及其耦合过程
气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系。如图1所示, 陆地生态系统的碳氮循环存在紧密的耦合关系(Thornton et al., 2009; Niu et al., 2016)。碳通过植物光合作用进入陆地碳循环, 并通过植物呼吸、凋落物分解与土壤有机质分解过程返回大气, 从而形成一个循环系统。相比于碳循环, 陆地氮循环更加开放, 且多个氮输入(沉降、生物固氮、矿化作用等)与输出(植物吸收、淋溶、反硝化、固持等)过程同时影响土壤无机氮库的动态。Lu等(2013)与Bai等(2013)分别利用元分析方法估算了全球增温实验中陆地碳、氮循环过程的响应。目前比较明确的结论是气候变暖显著提高了土壤氮矿化速率, 从而增加土壤中氮的有效性。对碳循环而言, 当前的全球尺度碳循环模型普遍地预测气候变暖将削弱陆地生态系统的碳汇能力(Cox et al., 2000; Friedlingstein et al., 2006)。然而, 需要注意的是, 目前用于IPCC评估报告的模型预测结果大多未考虑养分循环对碳循环的调控作用。相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(Pe?uelas et al., 2013; Yuan & Chen, 2015; Mooshammer et al., 2017)。由于磷循环没有显著的气体通量过程, 且其转化过程具有速率低、时间长与跨空间等特点(Schlesinger & Bernhardt, 2012), 因此难以借助野外增温实验的手段开展机理性研究。目前已有的研究发现气候变暖在一定程度上会增强土壤中微生物的酶活性(Xue et al., 2016; Melillo et al., 2017), 加速土壤有机质的分解(Bai et al., 2013), 促进有效氮、有效磷的释放和植物对养分的吸收(Shaver et al., 2000; Melillo et al., 2011)。此外, 气候变暖也能够通过改变土壤湿度从而间接调控生态系统氮磷循环(Dijkstra et al., 2012; Greaver et al., 2016), 如通过提高土壤湿度从而增大磷的溶解率, 进而促进植物和微生物对磷的吸收(Lambers et al., 2006)。在增温引起干旱的生态系统中, 有机质矿化速率、磷的扩散速率降低, 植物和微生物对养分的吸收将受到水分胁迫(Greaver et al., 2016)。目前, 更多的研究主要关注增温对植物和微生物体内碳氮磷计量关系的影响(Dijkstra et al., 2012)。然而需要指出的是, 生物体内的碳氮磷计量关系对生物地球化学过程的耦合关系虽然具有重要指示作用, 但并不等同于该耦合关系。因此, 未来的研究仍需探明增温改变生态系统碳氮磷计量关系的生态学机理, 以及分析该关系的变化如何从不同时空尺度影响生态系统的服务功能。
围绕以上生态系统关键过程, 我们通过梳理已发表的文献资料, 进一步评估了其中10个受关注度较高过程响应气候变暖的置信度(图2)。目前置信度最高的现象是春季物候提前现象, 不仅证据量充足而且一致性较高。然而, 仍然需要指出的是, 近期的一些研究发现春季植物物候对温度的敏感性呈下降趋势(Fu et al., 2015), 因此可能使未来研究之间的一致性降低。对土壤有机质加速分解与土壤矿化速率加快等现象而言, 虽然研究的数量较少, 但是结论高度一致。光合作用的过补偿效应(Wan et al., 2009)虽然已提出十余年, 但是不同生态系统报道的结果存在较大差异, 因此仍需要更多的研究揭示调控该现象的生物学机理。此外, 呼吸作用的热适应性现象在植物叶片中一致性非常高, 但是对土壤而言则置信度较低。因此, 我们建议未来的研究进一步关注证据量少且一致性低的关键生态系统过程, 以期发现其背后的普适性生态学机制。
图2
新窗口打开|下载原图ZIP|生成PPT图2生态系统部分关键过程响应气候变暖的证据量、一致性及置信度。证据量是指报道该生态系统过程的研究文献数量, 一致性是指所有文献中支持该响应现象的百分比例。置信度由证据量与一致性的乘积表示。该方法参考了第五次IPCC报告(IPCC, 2013)中的置信度概念, 并沿用了Xia等(2014)一文中的表达方法。本图中涉及的具体发表文献请见附录I。
Fig. 2Evidence, agreement and thus confidence of key ecosystem processes in response to climate warming. “Evidence” shows the number of studies that report on ecosystem processes. “Agreement” indicates the percentage of evidence supporting the specific warming response. Confidence is the product of “Evidence” and “Agreement” and is based on the confidence concept in the fifth IPCC report (IPCC, 2013). The figure was adapted from Xia et al. (2014). Data was obtained by a comprehensive literature search (Supplement I). ① photosynthetic acclimation; ② photosynthetic overcomepensation; ③ acclimation of plant respiration; ④ acclimation of soil respiration; ⑤ earlier spring phenology; ⑥ delayed autumn phenology; ⑦ changed species composition of plant community; ⑧ enhanced ecosystem productivity; ⑨ faster decomposition of soil organic matter; ⑩ faster soil nutrient mineralization.
2 前沿方向展望
本研究调研了2000年以来发表于Science、Nature、PNAS与Global Change Biology 4本优秀期刊的相关论文, 得出了以下几个比较明显的趋势。首先, 最近十年中, 国内第一单位发表的论文数量呈现上升趋势(图3A); 其次, Science与PNAS主要发表以观测数据为基础的研究论文, 而Nature与Global Change Biology则发表更多实验性研究论文(图3B); 此外, 过去发表的论文大多包含生理生态学过程与植物群落动态, 而且不同期刊对不同生态系统过程的发表比例有差异(图3C)。通过仔细研究近期的相关学术论文, 可以得出若干陆地生态系统与气候变暖相关的前沿方向。以下列举五方面内容, 谨供国内相关领域参考。图3
新窗口打开|下载原图ZIP|生成PPT图34份主流期刊(Science、Nature、PNAS与Global Change Biology (GCB))在2000-2019年间的发表文章数量(A)及其在研究方法(B)与生态学过程(C)方面的分布情况。论文检索结果来源于各期刊网站, 首先采用关键词“warming”进行搜索。然后, 再逐篇筛查是否包含陆地生态系统过程。中国地区的文章即第一作者单位为中国境内的研究机构。
Fig. 3Publications of four high-impact journals (Science、Nature、PNAS与Global Change Biology (GCB))(2000-2019), including the total number of papers (A) and their distribution in different methods (B) and ecological processes (C). Literature was first searched by the keyword “warming” from the homepage of each journal, then manually screened for whether it includes terrestrial ecosystem processes. The black line for “China” represents the published papers with the first affiliated address located in China.
2.1 物种性状与生态系统功能
植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(Wright et al., 2004; Kunstler et al., 2016), 常见的功能性状有表征植物资源利用能力的比叶面积、叶氮含量、胞间和大气CO2浓度比、边材和叶面积之比等; 表征植物光合能力的最大羧化速率和最大电子传递速率等(Reich et al., 1997; Reich, 2014)。植物功能性状既取决于遗传因素, 又受到外界环境的修饰作用(van Bodegom et al., 2012)。全球变暖可以直接影响植物的功能性状(Cui et al., 2020), 进而影响生态系统结构和功能(Atkin et al., 2008; Meng et al., 2015; Doughty et al., 2018)。植物功能性状对气候变暖的响应, 在预测植被分布、反映植被对气候变化的响应和评估生态系统服务功能等方面发挥着重要的作用。尽管已有成果有力地推动了全球变化生态学的发展, 但仍存在很多值得发展和探索的空白区域: (1)目前功能性状的研究与理论发展主要基于个体水平的观测。不同植物个体对气候变暖的响应模式不同, 根据个体反应难以预测群落或生态系统的整体响应模式, 未来应该加强群落或生态系统水平性状的观测研究(He et al., 2019)。(2)功能性状的研究主要集中于地上性状, 地下性状对于植物生长发育、养分循环等同样至关重要(Ma et al., 2018)。(3)缺乏增温梯度控制实验研究, 以往的实验模拟研究大多没有增温梯度, 难以深入探究功能性状对于气候变暖的敏感性及适应性。(4)基于植被功能性状及其环境变异性对动态植被模型进行改进(Verheijen et al., 2015; Ma et al., 2017), 发展我国自主产权的动态植被模型。土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(Wieder et al., 2015)。全球变暖可能会改变土壤微生物结构和功能组成, 从而影响植物与土壤微生物之间的相互作用与反馈(Xue et al., 2016)。然而, 目前学术界对土壤微生物群落如何响应气候变暖等问题认识不足, 且缺乏相关实验证据, 成为了限制陆地生态系统气候反馈预测的重要因素(Li et al., 2014; Abramoff et al., 2018)。因此, 未来需要借助新兴技术手段及方法加强对微生物关键过程和机理的研究, 如利用高通量测序手段对微生物群落进行全面而准确地分析; 借助稳定同位素标记进行代谢途径、养分分配等机理研究。
2.2 生物地球化学循环的耦合过程
生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(Heimann & Reichstein, 2008; Arneth et al., 2010)。然而, 目前对于各个元素循环间耦合机制的理解十分有限, 且生物地球化学循环对气候变暖的响应可能存在长期多相性, 即各个过程的短期响应在长期可能发生逆转(Melillo et al., 2002, 2017; Reich et al., 2018a)。同时, 由于对相关机理的理解尚不成熟, 及相关过程观测数据的欠缺, 导致模型模拟的结果存在很大的不确定性。在未来, 一方面需要借助更多的长期控制实验深入研究关键过程的变化机理, 另一方面则需要将实验研究结果与过程模型相结合以优化模型各个过程的模拟。目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(Rumpel & K?gel-Knabner, 2011)。但是, 深层土壤的碳含量占整个土壤碳库的一半以上, 而且其C:N的变化和丰富的化学物质成分表明深层土壤物质循环具有强烈的生化反应过程, 这些过程给土壤碳循环的研究带来很大的不确定性(Salome et al., 2010; Rumpel & K?gel-Knabner, 2011)。例如, 在深层土壤碳循环过程中, 新的土壤有机碳输入会激发深层土壤有机碳的分解(Rumpel & K?gel-Knabner, 2011)。而且, 在对气候变化的响应方面, 深层土壤有机碳的机理和浅层土壤有很大的区别, 例如深层土壤面对扰动更加容易矿化(Salome et al., 2010)。近年来, 在美国明尼苏达州的云杉林-泥炭地生态系统(Wilson et al., 2016; Hanson et al., 2017; Richardson et al., 2018)与加利福尼亚州的针叶林生态系统(Pries et al., 2017)都开展了全土壤坡面的增温实验。开展这些实验的一个重要科学假设是地球系统模式往往预测气候变暖提高了全土壤坡面的温度。然而需要注意的是, 当前地球系统模式中的陆面模式大多没有考虑土壤的深度分层, 因此其预测的土壤温度变化仍需更多的观测资料进行验证。尽管如此, 在气候变暖的情境下准确预测土壤碳循环的变化趋势, 仍需更加注重对深层土壤的研究(Chaopricha & Marin-Spiotta, 2014)。
冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(Schuur et al., 2009; Koven et al., 2011)。一方面温度上升会加速冻土融化, 刺激微生物分解, 增加土壤有机碳释放, 从而对全球气候变化起到正反馈作用并加速全球变暖(Tarnocai et al., 2009; Koven et al., 2011; Schuur et al., 2015)。另一方面, 气候变暖会加速土壤氮磷矿化, 刺激冻土区植被生长, 进而增加生态系统碳固定(Ding et al., 2017; Zhu et al., 2017)。由于缺乏长期观测资料, 已有的研究结果对于气候变暖下植被生长碳累积是否能抵消冻土融化造成的碳损失仍存在较大争议。同时, 由于冻土区土壤碳循环过程的复杂性, 当前全球陆地碳循环模型对冻土区生产力的模拟和预测存在2-3倍的差异(Xia et al., 2017)。因此, 未来冻土区的研究应该加强探索气候变暖对生态系统碳氮磷交互作用的生态学机理(Li et al., 2017)。
2.3 生态系统对极端低温与高温事件的响应与适应机理
随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(Fischer & Knutti, 2015; Dong et al., 2017)。极端低温和高温对陆地生态系统的结构和功能以及碳循环过程造成了严重的破坏(Cavanaugh et al., 2014; Perkins, 2015)。其中极端低温事件会影响生物学温度阈值, 导致生物多样性降低(Taylor et al., 2006; Miller & Barry, 2009), 生态系统生产力下降(Doran et al., 2002; Marchand et al., 2006), 同时也会使入侵物种减少(Walther et al., 2002; Firth et al. 2011), 抑制虫害爆发(Jentsch & Beierkuhnlein, 2008)。极端高温事件既能直接影响动植物的生理过程(Smith, 2011; Teskey et al., 2015; Harris et al., 2018), 也会通过改变土壤水分状况间接作用于植物光合作用和呼吸作用(Anderegg et al., 2012; Choat et al., 2012)。极端高温胁迫的滞后影响包括火灾、病原体和虫害暴发风险等都会进一步对陆地植被生长与生态系统生产力造成损害(van Mantgem et al., 2009; Gaylord et al., 2013)。陆地植被对于长期温度变化具有一定的适应性, 可在一定程度上减少极端事件的破坏性(Niu et al., 2012)。生态系统对极端温度事件的抵抗力以及灾害发生后的恢复情况也是目前研究的热点和难点问题(Ruthrof et al., 2018)。未来的研究需要定量化分析极端温度事件的正负效应, 生态系统抵抗和恢复机制及其驱动因素, 并建立完善的观测体系记录极端温度事件与生态系统间的联系(Flach et al., 2018)。
2.4 不对称性增温对生态系统的特异性影响
IPCC第五次评估报告指出, 全球气温的升高在昼夜间和季节间均呈现出明显的不对称性, 即平均夜间增温幅度大于白天增温幅度(Easterling et al., 1997; Hartman et al., 2013), 而中高纬度地区冬季和春季的增温速度比夏季快(Xu et al., 2013)。昼夜和季节的不对称增温对植物的生理、物候及生态系统功能都存在重要影响(Xia et al., 2014)。昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(Peng et al., 2013), 夜间增温则刺激植物呼吸作用导致CO2的释放(Turnbull et al., 2002; Peng et al., 2004)。近年来的一些研究报道了夜间增温对生态系统碳循环的重要影响。例如, 温室和野外实验发现在干旱和半干旱区域夜间增温对光合作用的过补偿现象(Wan et al., 2009), 并促进干旱区的植物生长与生态系统生产力(Peng et al., 2013; Xia et al., 2014), 基于大尺度的遥感观测数据却发现夜间增温对全球热带生态系统的碳汇能力表现为负作用(Anderegg et al., 2015)。截至目前, 关于陆地生态系统如何响应昼夜不对称增温的实验研究仍然局限于草地生态系统(Xia et al., 2014), 因此需要在更多的生态系统进行验证和研究。最近, Gaston (2019)甚至提出“夜间生态学” (Nighttime Ecology)的概念, 呼吁生态学领域加强对夜间生态学过程的关注。季节性不对称的增温主要体现在冬春季相对增温明显。冬春季变暖一方面促使植物的生长季提前(Wolkovich et al., 2012), 另一方面减少了雪被覆盖厚度从而对地下生态学过程产生复杂影响(Fitzhugh et al., 2001)。此外, 不同季节的增温可能会通过“滞后” (Xia et al., 2014)或“补偿”作用(Buermann et al., 2018)互相影响。因此, 未来的研究难点在于如何在昼夜与季节尺度整合不同生态系统过程, 并使观测数据能覆盖夜间与冬季等易被忽视的时期。
2.5 生态系统的模拟与预测
生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题。回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(Clark et al., 2001; Dietze et al., 2018)。然而, 目前生态系统过程模型存在巨大的不确定性(Luo et al., 2009; Xia et al., 2017)。为了提高生态系统模型模拟和预测的准确性, 需要在分析和降低模型的不确定性, 观测数据和模型的融合, 以及生态系统对气候变化的反馈作用等领域进一步加强研究。如图3所示, 自2000年以来Science、Nature、PNAS与Global Change Biology 4个期刊发表了大量关于陆地生态系统响应与适应气候变暖的学术论文。除了实验与观测以外, 模型模拟在近年来也成为了主流的研究手段。随着对全球变化响应机理的深入研究, 生态系统模型的结构越来越复杂, 因此进一步增加了不同模型间的差异(Xia et al., 2013; Shi et al., 2018)。总体而言, 模型的模拟不确定性主要有3个来源, 包括驱动数据、模型结构和参数(Knutti & Sedlá?ek, 2013; Todd-Brown et al., 2013)。近年来, 针对模型间模拟差异的溯源性分析和基准性分析成为了评估与改进模型的重要方法。因此, 如何借助模型比较项目、溯源性分析和数据同化等方法降低模型不确定性成为未来模型开发和探索的主要发展方向。多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(Medlyn et al., 2015, 2016)。多尺度数据-模型融合是近年来发展起来的生态系统研究的新方法, 包括利用多尺度观测数据通过前推和反演方法相结合优化模型结构和参数(Luo et al., 2003; Rayner et al., 2005), 利用多源观测数据对模型结果进行验证和评估(Xia et al., 2017; Yao et al., 2018), 应用连续观测数据驱动模型并逐步改进模型内在机理假设(Norby et al., 2016)。如图4所示, 本文建议未来的研究需要整合实验、野外调查与模型等多种研究方法。然而, 模型-数据融合的应用和拓展还存在诸多问题, 如小尺度生理过程和个体反应如何量化到模型构建当中, 物种或群落的差异性响应在模型当中如何表征, 以及如何用模型模拟结果指导实验观测等。
图4
新窗口打开|下载原图ZIP|生成PPT图4整合实验、野外调查观测与模型方法研究陆地生态系统响应与适应气候变暖的思路框架。图中的实验与模型的整合参考了Medlyn等(2015)的思路。需要说明的是, 该框架在研究具体的科学问题时需要根据实际情况进行调整。
Fig. 4Conceptual framework of experiments, field observations, and modeling to study response and adaptation of terrestrial ecosystems to warming. The integration of experiments and models in the figure was adapted from Medlyn et al. (2015). It should be noted that this framework needs to be adjusted according to the specific scientific question.
在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(Friedlingstein et al., 2003; Heimann & Reichstein, 2008)。然而, 自然生态系统对气候变化的反馈机理远比模型更加复杂(Cao & Woodward, 1998; Arneth et al., 2010; van Nes et al., 2015)。例如, 最近的一项研究在位于冰岛的亚北极草地中测定了128个生态系统变量, 并利用天然的地热温度梯度评估了生态系统对短期(5-8年)与长期(>50年)气候变暖的响应模式(Walker et al., 2019)。该研究发现长期气候变暖会使生态系统发生稳态迁移, 即产生新的生物群落并导致物种丰富度、生物量与土壤有机质含量下降。迄今为止, 生态系统对气候变化的反馈机理存在一些仍无法定量的理论假设, 例如植被光合与呼吸作用对温度的适应性、土壤碳库的激发效应和非结构性碳水化合物的作用等(Luo et al., 2001; Hoch et al., 2003; Kroner & Way,2016; Liang et al., 2018; Du et al., 2020)。所以, 在未来生态系统模型的发展中, 需要更加深入地研究生态系统对气候变化的反馈机理以及合适的模型化手段, 以提高模型模拟和预测的能力。
3 总结
在过去几十年中, 国内外生态学界在“陆地生态系统响应与适应气候变暖”这一领域取得了一系列重要成果。基于以上文献综述, 可以获得以下可信度较高的结论: (1)植物光合作用与呼吸作用对温度升高的响应与适应过程存在差异, 使气候变暖对生态系统净碳平衡的影响呈现出显著的时空变异; (2)植物的春季物候对气候变暖十分敏感, 但近年来呈现出温度敏感性下降的趋势; (3)气候变暖伴随着土壤干旱化增大了全球森林的死亡风险; (4)生物地球化学循环对长期升温的响应可能存在周期性的变化。除此之外, 其他进展较快的方向包括冻土区碳循环、深层土壤碳循环、植物群落结构变化、土壤微生物结构与功能等。然而, 这些研究依然存在一些共性不足, 主要体现在: (1)过去的研究设计更多针对气候变暖如何“影响”陆地生态系统, 但对陆地生态系统如何“适应”气候变暖研究相对较少; (2)大多关注森林与草地生态系统, 对湿地与荒漠等生态系统等研究较少; (3)实验设计多采用平均温升高或长期增温, 对极端温度事件的响应与适应机理缺乏野外实验研究; (4)主要关注碳循环本身, 而忽略了水、氮、磷等循环对碳循环的调控作用; (5)大多采用实验、观测或模型为研究手段, 极少有研究能够同时整合多种研究方法。这些方面还需要在未来的研究中逐步加强。
附录I 图2中涉及的参考文献列表
Supplement I List of references involved in Fig. 2http://www.plant-ecology.com/fileup/1005-264X/PDF/cjpe.2019.0323-S1.pdf
致谢
感谢华东师范大学魏宁、周健、姜铭在文献资料整理中给予的帮助。参考文献 原文顺序
文献年度倒序
文中引用次数倒序
被引期刊影响因子
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DOI:10.1111/gcb.14045URLPMID:29322601 [本文引用: 1]
The magnitude and direction of carbon cycle feedbacks under climate warming remain uncertain due to insufficient knowledge about the temperature sensitivities of soil microbial processes. Enzymatic rates could increase at higher temperatures, but this response could change over time if soil microbes adapt to warming. We used the Arrhenius relationship, biochemical transition state theory, and thermal physiology theory to predict the responses of extracellular enzyme Vmax and Km to temperature. Based on these concepts, we hypothesized that Vmax and Km would correlate positively with each other and show positive temperature sensitivities. For enzymes from warmer environments, we expected to find lower Vmax , Km , and Km temperature sensitivity but higher Vmax temperature sensitivity. We tested these hypotheses with isolates of the filamentous fungus Neurospora discreta collected from around the globe and with decomposing leaf litter from a warming experiment in Alaskan boreal forest. For Neurospora extracellular enzymes, Vmax Q10 ranged from 1.48 to 2.25, and Km Q10 ranged from 0.71 to 2.80. In agreement with theory, Vmax and Km were positively correlated for some enzymes, and Vmax declined under experimental warming in Alaskan litter. However, the temperature sensitivities of Vmax and Km did not vary as expected with warming. We also found no relationship between temperature sensitivity of Vmax or Km and mean annual temperature of the isolation site for Neurospora strains. Declining Vmax in the Alaskan warming treatment implies a short-term negative feedback to climate change, but the Neurospora results suggest that climate-driven changes in plant inputs and soil properties are important controls on enzyme kinetics in the long term. Our empirical data on enzyme Vmax , Km , and temperature sensitivities should be useful for parameterizing existing biogeochemical models, but they reveal a need to develop new theory on thermal adaptation mechanisms.
DOI:10.1111/gcb.2005.11.issue-10URL [本文引用: 1]
DOI:10.1073/pnas.1521479112URLPMID:26644555 [本文引用: 1]
The terrestrial biosphere is currently a strong carbon (C) sink but may switch to a source in the 21st century as climate-driven losses exceed CO2-driven C gains, thereby accelerating global warming. Although it has long been recognized that tropical climate plays a critical role in regulating interannual climate variability, the causal link between changes in temperature and precipitation and terrestrial processes remains uncertain. Here, we combine atmospheric mass balance, remote sensing-modeled datasets of vegetation C uptake, and climate datasets to characterize the temporal variability of the terrestrial C sink and determine the dominant climate drivers of this variability. We show that the interannual variability of global land C sink has grown by 50-100% over the past 50 y. We further find that interannual land C sink variability is most strongly linked to tropical nighttime warming, likely through respiration. This apparent sensitivity of respiration to nighttime temperatures, which are projected to increase faster than global average temperatures, suggests that C stored in tropical forests may be vulnerable to future warming.
URLPMID:22167807 [本文引用: 1]
DOI:10.3732/ajb.93.11.1633URLPMID:21642108 [本文引用: 1]
Using measurements of leaf respiratory O(2) uptake (R), we investigated whether immature and mature Arabidopsis thaliana (ecotype Columbia) leaves differed in their response to temperature. Confocal microscopy (using plants with mitochondrially targeted green fluorescent protein [GFP]) was used to determine whether ontogenetic changes in R are associated with concomitant changes in mitochondrial morphology/abundance. Comparisons were made of warm-grown (25/20 degrees C) leaves, warm-grown leaves shifted to cold (5 degrees C) for 10 days, and cold-developed leaves. Short-term Q(10) values and the ability to cold-acclimate were determined. In warm-grown plants, rates of R per mass were highest in immature leaves, decreasing as leaves developed. Moreover, although mitochondrial size (5.6-6.5 mum(3)) remained constant during development, mitochondrial number per mum(3) declined from 0.01 to 0.003 as leaves expanded (i.e., mitochondrial density decreased). Immature and mature leaves did not differ in Q(10) values but did differ in their ability to cold-acclimate. Whereas mature leaves had clear evidence of cold acclimation (e.g., when measured at 25 degrees C, R was highest in cold-developed leaves), young leaves had none. Collectively, the results highlight the changes in rates of R, mitochondrial density, and biomass allocation associated with leaf development and that changes in respiratory flux associated with acclimation only take place within mature tissues.
DOI:10.1038/ngeo905URL [本文引用: 2]
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DOI:10.1016/S1360-1385(03)00136-5URLPMID:12878019 [本文引用: 3]
Temperature-mediated changes in plant respiration (R) are now accepted as an important component of the biosphere's response to global climate change. Here we discuss the underlying mechanisms responsible for the dynamic response of plant respiration to short and long-term temperature changes. The Q(10) is often assumed to be 2.0 (i.e. R doubles per 10 degrees C rise in temperature); however, the Q(10) is not constant (e.g. it declines near-linearly with increasing temperature). The temperature dependence of Q(10) is linked to shifts in the control exerted by maximum enzyme activity at low temperature and substrate limitations at high temperature. In the long term, acclimation of R to temperature is common, in effect reducing the temperature sensitivity of R to changes in thermal environment, with the temperature during plant development setting the maximal thermal acclimation of R.
DOI:10.1111/nph.12266URLPMID:23586968 [本文引用: 3]
We present an intra-annual stable carbon isotope (delta(13)C) study based on a labeling experiment to illustrate differences in temporal patterns of recent carbon allocation to wood structures of two functional types of trees, Podocarpus falcatus (a late-successional evergreen conifer) and Croton macrostachyus (a deciduous broadleaved pioneer tree), in a tropical mountain forest in Ethiopia. Dendrometer data, wood anatomical thin sections, and intra-annual delta(13)C analyses were applied. Isotope data revealed a clear annual growth pattern in both studied species. For P. falcatus, it was possible to synchronize annual delta(13) C peaks, wood anatomical structures and monthly precipitation patterns. The labeling signature was evident for three consecutive years. For C. macrostachyus, isotope data illustrate a rapid decline of the labeling signal within half a year. Our delta(13)C labeling study indicates a distinct difference in carryover effects between trees of different functional types. A proportion of the labeled delta(13)C is stored in reserves of wood parenchyma for up to 3 yr in P. falcatus. By contrast, C. macrostachyus shows a high turnover of assimilates and a carbon carryover effect is only detectable in the subsequent year.
DOI:10.1146/annurev.pp.31.060180.002423URL [本文引用: 2]
DOI:10.1038/nature10548URLPMID:22012261 [本文引用: 1]
Climate change is driving latitudinal and altitudinal shifts in species distribution worldwide, leading to novel species assemblages. Lags between these biotic responses and contemporary climate changes have been reported for plants and animals. Theoretically, the magnitude of these lags should be greatest in lowland areas, where the velocity of climate change is expected to be much greater than that in highland areas. We compared temperature trends to temperatures reconstructed from plant assemblages (observed in 76,634 surveys) over a 44-year period in France (1965-2008). Here we report that forest plant communities had responded to 0.54 degrees C of the effective increase of 1.07 degrees C in highland areas (500-2,600 m above sea level), while they had responded to only 0.02 degrees C of the 1.11 degrees C warming trend in lowland areas. There was a larger temperature lag (by 3.1 times) between the climate and plant community composition in lowland forests than in highland forests. The explanation of such disparity lies in the following properties of lowland, as compared to highland, forests: the higher proportion of species with greater ability for local persistence as the climate warms, the reduced opportunity for short-distance escapes, and the greater habitat fragmentation. Although mountains are currently considered to be among the ecosystems most threatened by climate change (owing to mountaintop extinction), the current inertia of plant communities in lowland forests should also be noted, as it could lead to lowland biotic attrition.
DOI:10.1038/s41586-018-0358-xURLPMID:30068952 [本文引用: 1]
Global soils store at least twice as much carbon as Earth's atmosphere(1,2). The global soil-to-atmosphere (or total soil respiration, RS) carbon dioxide (CO2) flux is increasing(3,4), but the degree to which climate change will stimulate carbon losses from soils as a result of heterotrophic respiration (RH) remains highly uncertain(5-8). Here we use an updated global soil respiration database(9) to show that the observed soil surface RH:RS ratio increased significantly, from 0.54 to 0.63, between 1990 and 2014 (P = 0.009). Three additional lines of evidence provide support for this finding. By analysing two separate global gross primary production datasets(10,11), we find that the ratios of both RH and RS to gross primary production have increased over time. Similarly, significant increases in RH are observed against the longest available solar-induced chlorophyll fluorescence global dataset, as well as gross primary production computed by an ensemble of global land models. We also show that the ratio of night-time net ecosystem exchange to gross primary production is rising across the FLUXNET2015(12) dataset. All trends are robust to sampling variability in ecosystem type, disturbance, methodology, CO2 fertilization effects and mean climate. Taken together, our findings provide observational evidence that global RH is rising, probably in response to environmental changes, consistent with meta-analyses(13-16) and long-term experiments(17). This suggests that climate-driven losses of soil carbon are currently occurring across many ecosystems, with a detectable and sustained trend emerging at the global scale.
DOI:10.1038/NCLIMATE2251URL [本文引用: 1]
Decomposition of organic matter strongly influences ecosystem carbon storage(1). In Earth-system models, climate is a predominant control on the decomposition rates of organic matter(2-5). This assumption is based on the mean response of decomposition to climate, yet there is a growing appreciation in other areas of global change science that projections based on mean responses can be irrelevant and misleading(6,7). We test whether climate controls on the decomposition rate of dead wood-a carbon stock estimated to represent 73 +/- 6 Pg carbon globally(8)-are sensitive to the spatial scale from which they are inferred. We show that the common assumption that climate is a predominant control on decomposition is supported only when local-scale variation is aggregated into mean values. Disaggregated data instead reveal that local-scale factors explain 73% of the variation in wood decomposition, and climate only 28%. Further, the temperature sensitivity of decomposition estimated from local versus mean analyses is 1.3-times greater. Fundamental issues with mean correlations were highlighted decades ago(9,10), yet mean climate-decomposition relationships are used to generate simulations that inform management and adaptation under environmental change. Our results suggest that to predict accurately how decomposition will respond to climate change, models must account for local-scale factors that control regional dynamics.
DOI:10.1038/s41586-018-0555-7URLPMID:30283105 [本文引用: 1]
Climate change is shifting the phenological cycles of plants(1), thereby altering the functioning of ecosystems, which in turn induces feedbacks to the climate system(2). In northern (north of 30 degrees N) ecosystems, warmer springs lead generally to an earlier onset of the growing season(3,4) and increased ecosystem productivity early in the season(5). In situ(6) and regional(7-9) studies also provide evidence for lagged effects of spring warmth on plant productivity during the subsequent summer and autumn. However, our current understanding of these lagged effects, including their direction (beneficial or adverse) and geographic distribution, is still very limited. Here we analyse satellite, field-based and modelled data for the period 1982-2011 and show that there are widespread and contrasting lagged productivity responses to spring warmth across northern ecosystems. On the basis of the observational data, we find that roughly 15 per cent of the total study area of about 41 million square kilometres exhibits adverse lagged effects and that roughly 5 per cent of the total study area exhibits beneficial lagged effects. By contrast, current-generation terrestrial carbon-cycle models predict much lower areal fractions of adverse lagged effects (ranging from 1 to 14 per cent) and much higher areal fractions of beneficial lagged effects (ranging from 9 to 54 per cent). We find that elevation and seasonal precipitation patterns largely dictate the geographic pattern and direction of the lagged effects. Inadequate consideration in current models of the effects of the seasonal build-up of water stress on seasonal vegetation growth may therefore be able to explain the differences that we found between our observation-constrained estimates and the model-constrained estimates of lagged effects associated with spring warming. Overall, our results suggest that for many northern ecosystems the benefits of warmer springs on growing-season ecosystem productivity are effectively compensated for by the accumulation of seasonal water deficits, despite the fact that northern ecosystems are thought to be largely temperature- and radiation-limited(10).
DOI:10.1111/nph.14258URLPMID:27768823 [本文引用: 1]
The biochemical model of C3 photosynthesis by Farquhar, von Caemmerer and Berry (FvCB) assumes that photosynthetic CO2 assimilation is limited by one of three biochemical processes that are not always easily discerned. This leads to improper assessments of biochemical limitations that limit the accuracy of the model predictions. We use the sensitivity of rates of CO2 assimilation and photosynthetic electron transport to changes in O2 and CO2 concentration in the chloroplast to evaluate photosynthetic limitations. Assessing the sensitivities to O2 and CO2 concentrations reduces the impact of uncertainties in the fixed parameters to a minimum and simultaneously entirely eliminates the need to determine the variable parameters of the model, such as Vcmax , J, or TP . Our analyses demonstrate that Rubisco limits carbon assimilation at high temperatures, while it is limited by triose phosphate utilization at lower temperatures and at higher CO2 concentrations. Measurements can be assigned a priori to one of the three functions of the FvCB model, allowing testing for the suitability of the selected fixed parameters of the model. This approach can improve the reliability of photosynthesis models on scales from the leaf level to estimating the global carbon budget.
DOI:10.1038/30460URL [本文引用: 1]
DOI:10.1073/pnas.1315800111URL [本文引用: 1]
Regional warming associated with climate change is linked with altered range and abundance of species and ecosystems worldwide. However, the ecological impacts of changes in the frequency of extreme events have not been as well documented, especially for coastal and marine environments. We used 28 y of satellite imagery to demonstrate that the area of mangrove forests has doubled at the northern end of their historic range on the east coast of Florida. This expansion is associated with a reduction in the frequency of "extreme" cold events (days colder than -4 degrees C), but uncorrelated with changes in mean annual temperature, mean annual precipitation, and land use. Our analyses provide evidence for a threshold response, with declining frequency of severe cold winter events allowing for poleward expansion of mangroves. Future warming may result in increases in mangrove cover beyond current latitudinal limits of mangrove forests, thereby altering the structure and function of these important coastal ecosystems.
DOI:10.1016/j.soilbio.2013.11.011URL [本文引用: 1]
DOI:10.1038/nature11688URL [本文引用: 1]
URLPMID:16177786 [本文引用: 1]
URLPMID:12719545 [本文引用: 1]
URLPMID:11474103 [本文引用: 1]
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DOI:10.1073/pnas.0600815103URLPMID:16954189 [本文引用: 1]
Shifting plant phenology (i.e., timing of flowering and other developmental events) in recent decades establishes that species and ecosystems are already responding to global environmental change. Earlier flowering and an extended period of active plant growth across much of the northern hemisphere have been interpreted as responses to warming. However, several kinds of environmental change have the potential to influence the phenology of flowering and primary production. Here, we report shifts in phenology of flowering and canopy greenness (Normalized Difference Vegetation Index) in response to four experimentally simulated global changes: warming, elevated CO(2), nitrogen (N) deposition, and increased precipitation. Consistent with previous observations, warming accelerated both flowering and greening of the canopy, but phenological responses to the other global change treatments were diverse. Elevated CO(2) and N addition delayed flowering in grasses, but slightly accelerated flowering in forbs. The opposing responses of these two important functional groups decreased their phenological complementarity and potentially increased competition for limiting soil resources. At the ecosystem level, timing of canopy greenness mirrored the flowering phenology of the grasses, which dominate primary production in this system. Elevated CO(2) delayed greening, whereas N addition dampened the acceleration of greening caused by warming. Increased precipitation had no consistent impacts on phenology. This diversity of phenological changes, between plant functional groups and in response to multiple environmental changes, helps explain the diversity in large-scale observations and indicates that changing temperature is only one of several factors reshaping the seasonality of ecosystem processes.
DOI:10.1038/s41558-018-0067-3URL [本文引用: 1]
DOI:10.1093/treephys/tpz034URLPMID:30924876 [本文引用: 1]
Gross primary production (GPP) is partitioned to autotrophic respiration (Ra) and net primary production (NPP), the latter being used to build plant tissues and synthesize non-structural and secondary compounds. Waring et al. (1998; Net primary production of forests: a constant fraction of gross primary production? Tree Physiol 18:129-134) suggested that a NPP:GPP ratio of 0.47 +/- 0.04 (SD) is universal across biomes, tree species and stand ages. Representing NPP in models as a fixed fraction of GPP, they argued, would be both simpler and more accurate than trying to simulate Ra mechanistically. This paper reviews progress in understanding the NPP:GPP ratio in forests during the 20 years since the Waring et al. paper. Research has confirmed the existence of pervasive acclimation mechanisms that tend to stabilize the NPP:GPP ratio and indicates that Ra should not be modelled independently of GPP. Nonetheless, studies indicate that the value of this ratio is influenced by environmental factors, stand age and management. The average NPP:GPP ratio in over 200 studies, representing different biomes, species and forest stand ages, was found to be 0.46, consistent with the central value that Waring et al. proposed but with a much larger standard deviation (+/-0.12) and a total range (0.22-0.79) that is too large to be disregarded.
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URLPMID:11089968 [本文引用: 1]
DOI:10.1073/pnas.230451497URLPMID:11069297 [本文引用: 1]
Net photosynthesis (Pn) is inhibited by moderate heat stress. To elucidate the mechanism of inhibition, we examined the effects of temperature on gas exchange and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activation in cotton and tobacco leaves and compared the responses to those of the isolated enzymes. Depending on the CO(2) concentration, Pn decreased when temperatures exceeded 35-40 degrees C. This response was inconsistent with the response predicted from the properties of fully activated Rubisco. Rubisco deactivated in leaves when temperature was increased and also in response to high CO(2) or low O(2). The decrease in Rubisco activation occurred when leaf temperatures exceeded 35 degrees C, whereas the activities of isolated activase and Rubisco were highest at 42 degrees C and >50 degrees C, respectively. In the absence of activase, isolated Rubisco deactivated under catalytic conditions and the rate of deactivation increased with temperature but not with CO(2). The ability of activase to maintain or promote Rubisco activation in vitro also decreased with temperature but was not affected by CO(2). Increasing the activase/Rubisco ratio reduced Rubisco deactivation at higher temperatures. The results indicate that, as temperature increases, the rate of Rubisco deactivation exceeds the capacity of activase to promote activation. The decrease in Rubisco activation that occurred in leaves at high CO(2) was not caused by a faster rate of deactivation, but by reduced activase activity possibly in response to unfavorable ATP/ADP ratios. When adjustments were made for changes in activation state, the kinetic properties of Rubisco predicted the response of Pn at high temperature and CO(2).
URLPMID:28541536 [本文引用: 1]
URLPMID:27905442 [本文引用: 2]
DOI:10.1038/s41467-020-16839-9URLPMID:32532992 [本文引用: 1]
Recent studies show coordinated relationships between plant leaf traits and their capacity to predict ecosystem functions. However, how leaf traits will change within species and whether interspecific trait relationships will shift under future environmental changes both remain unclear. Here, we examine the bivariate correlations between leaf economic traits of 515 species in 210 experiments which mimic climate warming, drought, elevated CO2, and nitrogen deposition. We find divergent directions of changes in trait-pairs between species, and the directions mostly do not follow the interspecific trait relationships. However, the slopes in the logarithmic transformed interspecific trait relationships hold stable under environmental changes, while only their elevations vary. The elevation changes of trait relationship are mainly driven by asymmetrically interspecific responses contrary to the direction of the leaf economic spectrum. These findings suggest robust interspecific trait relationships under global changes, and call for linking within-species responses to interspecific coordination of plant traits.
URLPMID:29382745 [本文引用: 1]
DOI:10.1111/j.1469-8137.2012.04349.xURL [本文引用: 2]
Nitrogen (N) and phosphorus (P) are essential nutrients for primary producers and decomposers in terrestrial ecosystems. Although climate change affects terrestrial N cycling with important feedbacks to plant productivity and carbon sequestration, the impacts of climate change on the relative availability of N with respect to P remain highly uncertain. In a semiarid grassland in Wyoming, USA, we studied the effects of atmospheric CO2 enrichment (to 600 ppmv) and warming (1.5/3.0 degrees C above ambient temperature during the day/night) on plant, microbial and available soil pools of N and P. Elevated CO2 increased P availability to plants and microbes relative to that of N, whereas warming reduced P availability relative to N. Across years and treatments, plant N : P ratios varied between 5 and 18 and were inversely related to soil moisture. Our results indicate that soil moisture is important in controlling P supply from inorganic sources, causing reduced P relative to N availability during dry periods. Both wetter soil conditions under elevated CO2 and drier conditions with warming can further alter N : P. Although warming may alleviate N constraints under elevated CO2, warming and drought can exacerbate P constraints on plant growth and microbial activity in this semiarid grassland.
DOI:10.1038/ngeo2945URL [本文引用: 1]
DOI:10.1007/s00382-016-3158-8URL [本文引用: 1]
URLPMID:11793010 [本文引用: 1]
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DOI:10.1038/s41559-018-0716-yURLPMID:30455442 [本文引用: 1]
URLPMID:30840319 [本文引用: 1]
DOI:10.1111/fec.v34.8URL [本文引用: 2]
DOI:10.1111/nph.15283URLPMID:29983005 [本文引用: 2]
Contents Summary 32 I. The importance of plant carbon metabolism for climate change 32 II. Rising atmospheric CO2 and carbon metabolism 33 III. Rising temperatures and carbon metabolism 37 IV. Thermal acclimation responses of carbon metabolic processes can be best understood when studied together 38 V. Will elevated CO2 offset warming-induced changes in carbon metabolism? 40 VI. No plant is an island: water and nutrient limitations define plant responses to climate drivers 41 VII. Conclusions 42 Acknowledgements 42 References 42 Appendix A1 48 SUMMARY: Plant carbon metabolism is impacted by rising CO2 concentrations and temperatures, but also feeds back onto the climate system to help determine the trajectory of future climate change. Here we review how photosynthesis, photorespiration and respiration are affected by increasing atmospheric CO2 concentrations and climate warming, both separately and in combination. We also compile data from the literature on plants grown at multiple temperatures, focusing on net CO2 assimilation rates and leaf dark respiration rates measured at the growth temperature (Agrowth and Rgrowth , respectively). Our analyses show that the ratio of Agrowth to Rgrowth is generally homeostatic across a wide range of species and growth temperatures, and that species that have reduced Agrowth at higher growth temperatures also tend to have reduced Rgrowth , while species that show stimulations in Agrowth under warming tend to have higher Rgrowth in the hotter environment. These results highlight the need to study these physiological processes together to better predict how vegetation carbon metabolism will respond to climate change.
DOI:10.1126/science.277.5324.364URL [本文引用: 1]
DOI:10.1007/BF00139439URL [本文引用: 1]
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DOI:10.1016/j.jembe.2011.02.007URL [本文引用: 1]
Global climate change and invasive species represent two of the biggest threats to the environment. Biological communities are responding to global climate change through poleward shifts in distribution, and changes in abundance and phenology of both native and non-native species. An increase in the frequency and magnitude of extreme weather events is predicted with global climate change. Much is known about mortality events of marine organisms in relation to warm thermal stress with relatively little known about cold thermal stress, particularly in the tropics. Intertidal species are particularly susceptible to fluctuations in aerial conditions and many are considered indicators of climate change. Perna viridis is a recent invader to the United States where it fouls hard substrates and soft sediment habitats. During winter 2007/08, a mortality event was observed for P. viridis across Tampa Bay, Florida. This mortality event coincided with extreme weather conditions when air temperatures dropped below 2 degrees C for a period of 6 h during low water. The minimum air temperature recorded was 0.53 degrees C. During this period water temperature remained relatively constant (similar to 20 degrees C). We provide strong evidence supporting the hypothesis that thermal stress relating to exposure to cold air temperatures during emersion was the primary factor underpinning the mortality event. Similar mortality events occurred in 2009 and 2010, also coinciding with prolonged exposure to low air temperatures. In the short term, weather may be responsible for the temporary trimming back of populations at the edge of their geographic range but in the longer-term, it is expected that climate warming will trigger the poleward movement of both native and non-native species potentially facilitating biotic homogenisation of marine communities. The challenge now is to devise adaptive management strategies in order to mitigate any potential negative impacts to native biodiversity. (C) 2011 Elsevier B.V.
DOI:10.1038/nclimate2617URL [本文引用: 1]
DOI:10.1126/science.1071617URLPMID:12040195 [本文引用: 1]
The average first flowering date of 385 British plant species has advanced by 4.5 days during the past decade compared with the previous four decades: 16% of species flowered significantly earlier in the 1990s than previously, with an average advancement of 15 days in a decade. Ten species (3%) flowered significantly later in the 1990s than previously. These data reveal the strongest biological signal yet of climatic change. Flowering is especially sensitive to the temperature in the previous month, and spring-flowering species are most responsive. However, large interspecific differences in this response will affect both the structure of plant communities and gene flow between species as climate warms. Annuals are more likely to flower early than congeneric perennials, and insect-pollinated species more than wind-pollinated ones.
DOI:10.1023/A:1013076609950URL [本文引用: 1]
Reductions in snow cover undera warmer climate may cause soil freezing eventsto become more common in northern temperateecosystems. In this experiment, snow cover wasmanipulated to simulate the late development ofsnowpack and to induce soil freezing. Thismanipulation was used to examine the effects ofsoil freezing disturbance on soil solutionnitrogen (N), phosphorus (P), and carbon (C)chemistry in four experimental stands (twosugar maple and two yellow birch) at theHubbard Brook Experimental Forest (HBEF) in theWhite Mountains of New Hampshire. Soilfreezing enhanced soil solution Nconcentrations and transport from the forestfloor. Nitrate (NO3–) was thedominant N species mobilized in the forestfloor of sugar maple stands after soilfreezing, while ammonium (NH4+) anddissolved organic nitrogen (DON) were thedominant forms of N leaching from the forestfloor of treated yellow birch stands. Rates ofN leaching at stands subjected to soil freezingranged from 490 to 4,600 mol ha–1yr–1, significant in comparison to wet Ndeposition (530 mol ha–1 yr–1) andstream NO3– export (25 mol ha–1yr–1) in this northern forest ecosystem. Soil solution fluxes of Pi from the forestfloor of sugar maple stands after soil freezingranged from 15 to 32 mol ha–1 yr–1;this elevated mobilization of Pi coincidedwith heightened NO3– leaching. Elevated leaching of Pi from the forestfloor was coupled with enhanced retention ofPi in the mineral soil Bs horizon. Thequantities of Pi mobilized from the forestfloor were significant relative to theavailable P pool (22 mol ha–1) as well asnet P mineralization rates in the forest floor(180 mol ha–1 yr–1). Increased fineroot mortality was likely an important sourceof mobile N and Pi from the forest floor,but other factors (decreased N and P uptake byroots and increased physical disruption of soilaggregates) may also have contributed to theenhanced leaching of nutrients. Microbialmortality did not contribute to the acceleratedN and P leaching after soil freezing. Resultssuggest that soil freezing events may increaserates of N and P loss, with potential effectson soil N and P availability, ecosystemproductivity, as well as surface wateracidification and eutrophication.]]>
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DOI:10.1038/NCLIMATE1796URL [本文引用: 1]
Soils are the largest repository of organic carbon (C) in the terrestrial biosphere and represent an important source of carbon dioxide (CO2) to the atmosphere, releasing 60-75 Pg C annually through microbial decomposition of organic materials(1,2). A primary control on soil CO2 flux is the efficiency with which the microbial community uses C. Despite its critical importance to soil-atmosphere CO2 exchange, relatively few studies have examined the factors controlling soil microbial efficiency. Here, we measured the temperature response of microbial efficiency in soils amended with substrates varying in lability. We also examined the temperature sensitivity of microbial efficiency in response to chronic soil warming in situ. We find that the efficiency with which soil microorganisms use organic matter is dependent on both temperature and substrate quality, with efficiency declining with increasing temperatures for more recalcitrant substrates. However, the utilization efficiency of a more recalcitrant substrate increased at higher temperatures in soils exposed to almost two decades of warming 5 degrees C above ambient. Our work suggests that climate warming could alter the decay dynamics of more stable organic matter compounds, thereby having a positive feedback to climate that is attenuated by a shift towards a more efficient microbial community in the longer term.
DOI:10.1175/JCLI3800.1URL [本文引用: 1]
DOI:10.3402/tellusb.v55i2.16765URL [本文引用: 1]
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DOI:10.1111/geb.12210URL [本文引用: 1]
LocationWestern Central Europe.MethodsTemporal spring phenology trends (leaf unfolding dates) were examined using 1,001,678 in situ observations of 31 plant species at 3984 stations, as well as NDVI-based start-of-season dates, obtained using five different methods, across the pixels that included the phenology stations.ResultsIn situ and NDVI observations both indicated that spring phenology significantly advanced during the period 1982-2011 at an average rate of -0.45 daysyr(-1). This trend was not uniform across the period and significantly weakened over the period 2000-2011. Furthermore, opposite trends were found between in situ and NDVI observations over the period 2000-2011. Averaged over all species, the in situ observations indicated a slower but still advancing trend for leaf unfolding, whereas the NDVI series showed a delayed spring phenology.Main conclusionsThe recent trend reversal in the advancement of spring phenology in western Central Europe is likely to be related to the response of early spring species to the cooling trend in late winter. In contrast, late spring species continued to exhibit advanced leaf unfolding, which is consistent with the warming trend during spring months. Because remote sensing does not distinguish between species, the signal of growing-season onset may only reflect the phenological dynamics of these earliest species in the pixel, even though most species still exhibit advancing trends.]]>
DOI:10.1038/nature15402URLPMID:26416746 [本文引用: 2]
Earlier spring leaf unfolding is a frequently observed response of plants to climate warming. Many deciduous tree species require chilling for dormancy release, and warming-related reductions in chilling may counteract the advance of leaf unfolding in response to warming. Empirical evidence for this, however, is limited to saplings or twigs in climate-controlled chambers. Using long-term in situ observations of leaf unfolding for seven dominant European tree species at 1,245 sites, here we show that the apparent response of leaf unfolding to climate warming (ST, expressed in days advance of leaf unfolding per degrees C warming) has significantly decreased from 1980 to 2013 in all monitored tree species. Averaged across all species and sites, ST decreased by 40% from 4.0 +/- 1.8 days degrees C(-1) during 1980-1994 to 2.3 +/- 1.6 days degrees C(-1) during 1999-2013. The declining ST was also simulated by chilling-based phenology models, albeit with a weaker decline (24-30%) than observed in situ. The reduction in ST is likely to be partly attributable to reduced chilling. Nonetheless, other mechanisms may also have a role, such as 'photoperiod limitation' mechanisms that may become ultimately limiting when leaf unfolding dates occur too early in the season. Our results provide empirical evidence for a declining ST, but also suggest that the predicted strong winter warming in the future may further reduce ST and therefore result in a slowdown in the advance of tree spring phenology.
DOI:10.1086/702250URLPMID:30912975 [本文引用: 1]
The existence of a synthetic program of research on what was then termed the
DOI:10.1111/nph.12174URLPMID:23421561 [本文引用: 1]
To test the hypothesis that drought predisposes trees to insect attacks, we quantified the effects of water availability on insect attacks, tree resistance mechanisms, and mortality of mature pinon pine (Pinus edulis) and one-seed juniper (Juniperus monosperma) using an experimental drought study in New Mexico, USA. The study had four replicated treatments (40 x 40 m plot/replicate): removal of 45% of ambient annual precipitation (H2 O-); irrigation to produce 125% of ambient annual precipitation (H2 O+); a drought control (C) to quantify the impact of the drought infrastructure; and ambient precipitation (A). Pinon began dying 1 yr after drought initiation, with higher mortality in the H2 O- treatment relative to other treatments. Beetles (bark/twig) were present in 92% of dead trees. Resin duct density and area were more strongly affected by treatments and more strongly associated with pinon mortality than direct measurements of resin flow. For juniper, treatments had no effect on insect resistance or attacks, but needle browning was highest in the H2 O- treatment. Our results provide strong evidence that >/= 1 yr of severe drought predisposes pinon to insect attacks and increases mortality, whereas 3 yr of the same drought causes partial canopy loss in juniper.
URLPMID:24895088 [本文引用: 1]
DOI:10.1038/nclimate3088URL [本文引用: 2]
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DOI:10.1016/j.tree.2018.11.004URLPMID:30527959 [本文引用: 1]
As the range of studies on macroecology and functional traits expands, integration of traits into higher-level approaches offers new opportunities to improve clarification of larger-scale patterns and their mechanisms and predictions using models. Here, we propose a framework for quantifying 'ecosystem traits' and means to address the challenges of broadening the applicability of functional traits to macroecology. Ecosystem traits are traits or quantitative characteristics of organisms (plants, animals, and microbes) at the community level expressed as the intensity (or density) normalized per unit land area. Ecosystem traits can inter-relate and integrate data from field trait surveys, eddy-flux observation, remote sensing, and ecological models, and thereby provide new resolution of the responses and feedback at regional to global scale.
DOI:10.1038/nature06591URLPMID:18202646 [本文引用: 2]
URLPMID:27001849 [本文引用: 1]
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DOI:10.1007/BF00389400URLPMID:24515632 [本文引用: 1]
Evolution of CO2 into CO2-free air was measured in the light and in the dark over a range of temperatures from 15 to 50 degrees . Photosynthetic rates were measured in air and O2-free air over the same range of temperatures. Respiration in the light had a different sensitivity to temperature compared with respiration in the dark. At the lower temperatures the rate of respiration in the light was higher than respiration in the dark, whereas at temperatures above 40 degrees the reverse was observed. For any one species the maximum rates of photosynthesis and photorespiration occur at about the same temperature. The maximum rate for dark respiration generally is found at a temperature about 10 degrees higher. Zea mays and Atriplex nummularia showed no enhancement of photosynthesis in O2-free air nor any evolution of CO2 in CO2-free air at any of the temperatures.
DOI:10.1126/science.105.2727.367URLPMID:17800882 [本文引用: 1]
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DOI:10.1038/s41559-019-0838-xURLPMID:30858592 [本文引用: 1]
The global distribution of the optimum air temperature for ecosystem-level gross primary productivity ([Formula: see text]) is poorly understood, despite its importance for ecosystem carbon uptake under future warming. We provide empirical evidence for the existence of such an optimum, using measurements of in situ eddy covariance and satellite-derived proxies, and report its global distribution. [Formula: see text] is consistently lower than the physiological optimum temperature of leaf-level photosynthetic capacity, which typically exceeds 30 degrees C. The global average [Formula: see text] is estimated to be 23 +/- 6 degrees C, with warmer regions having higher [Formula: see text] values than colder regions. In tropical forests in particular, [Formula: see text] is close to growing-season air temperature and is projected to fall below it under all scenarios of future climate, suggesting a limited safe operating space for these ecosystems under future warming.
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DOI:10.1016/j.crte.2008.07.002URL [本文引用: 1]
DOI:10.1038/nature13604URLPMID:25186902 [本文引用: 1]
Soils store about four times as much carbon as plant biomass, and soil microbial respiration releases about 60 petagrams of carbon per year to the atmosphere as carbon dioxide. Short-term experiments have shown that soil microbial respiration increases exponentially with temperature. This information has been incorporated into soil carbon and Earth-system models, which suggest that warming-induced increases in carbon dioxide release from soils represent an important positive feedback loop that could influence twenty-first-century climate change. The magnitude of this feedback remains uncertain, however, not least because the response of soil microbial communities to changing temperatures has the potential to either decrease or increase warming-induced carbon losses substantially. Here we collect soils from different ecosystems along a climate gradient from the Arctic to the Amazon and investigate how microbial community-level responses control the temperature sensitivity of soil respiration. We find that the microbial community-level response more often enhances than reduces the mid- to long-term (90 days) temperature sensitivity of respiration. Furthermore, the strongest enhancing responses were observed in soils with high carbon-to-nitrogen ratios and in soils from cold climatic regions. After 90 days, microbial community responses increased the temperature sensitivity of respiration in high-latitude soils by a factor of 1.4 compared to the instantaneous temperature response. This suggests that the substantial carbon stores in Arctic and boreal soils could be more vulnerable to climate warming than currently predicted.
DOI:10.1038/382146a0URL [本文引用: 1]
URLPMID:29666247 [本文引用: 1]
DOI:10.1038/nature03226URLPMID:15662420 [本文引用: 1]
The sensitivity of soil carbon to warming is a major uncertainty in projections of carbon dioxide concentration and climate. Experimental studies overwhelmingly indicate increased soil organic carbon (SOC) decomposition at higher temperatures, resulting in increased carbon dioxide emissions from soils. However, recent findings have been cited as evidence against increased soil carbon emissions in a warmer world. In soil warming experiments, the initially increased carbon dioxide efflux returns to pre-warming rates within one to three years, and apparent carbon pool turnover times are insensitive to temperature. It has already been suggested that the apparent lack of temperature dependence could be an artefact due to neglecting the extreme heterogeneity of soil carbon, but no explicit model has yet been presented that can reconcile all the above findings. Here we present a simple three-pool model that partitions SOC into components with different intrinsic turnover rates. Using this model, we show that the results of all the soil-warming experiments are compatible with long-term temperature sensitivity of SOC turnover: they can be explained by rapid depletion of labile SOC combined with the negligible response of non-labile SOC on experimental timescales. Furthermore, we present evidence that non-labile SOC is more sensitive to temperature than labile SOC, implying that the long-term positive feedback of soil decomposition in a warming world may be even stronger than predicted by global models.
DOI:10.1038/NCLIMATE1716URL [本文引用: 1]
Estimates of impacts from anthropogenic climate change rely on projections from climate models. Uncertainties in those have often been a limiting factor, in particular on local scales. A new generation of more complex models running scenarios for the upcoming Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) is widely, and perhaps naively, expected to provide more detailed and more certain projections. Here we show that projected global temperature change from the new models is remarkably similar to that from those used in IPCC AR4 after accounting for the different underlying scenarios. The spatial patterns of temperature and precipitation change are also very consistent. Interestingly, the local model spread has not changed much despite substantial model development and a massive increase in computational capacity. Part of this model spread is irreducible owing to internal variability in the climate system, yet there is also uncertainty from model differences that can potentially be eliminated. We argue that defining progress in climate modelling in terms of narrowing uncertainties is too limited. Models improve, representing more processes in greater detail. This implies greater confidence in their projections, but convergence may remain slow. The uncertainties should not stop decisions being made.
DOI:10.1073/pnas.1103910108URL [本文引用: 2]
Permafrost soils contain enormous amounts of organic carbon, which could act as a positive feedback to global climate change due to enhanced respiration rates with warming. We have used a terrestrial ecosystem model that includes permafrost carbon dynamics, inhibition of respiration in frozen soil layers, vertical mixing of soil carbon from surface to permafrost layers, and CH4 emissions from flooded areas, and which better matches new circumpolar inventories of soil carbon stocks, to explore the potential for carbon-climate feedbacks at high latitudes. Contrary to model results for the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), when permafrost processes are included, terrestrial ecosystems north of 60 degrees N could shift from being a sink to a source of CO2 by the end of the 21st century when forced by a Special Report on Emissions Scenarios ( SRES) A2 climate change scenario. Between 1860 and 2100, the model response to combined CO2 fertilization and climate change changes from a sink of 68 Pg to a 27 + -7 Pg sink to 4 + -18 Pg source, depending on the processes and parameter values used. The integrated change in carbon due to climate change shifts from near zero, which is within the range of previous model estimates, to a climate-induced loss of carbon by ecosystems in the range of 25 + -3 to 85 + -16 Pg C, depending on processes included in the model, with a best estimate of a 62 + -7 Pg C loss. Methane emissions from high-latitude regions are calculated to increase from 34 Tg CH4/y to 41-70 TgCH(4)/y, with increases due to CO2 fertilization, permafrost thaw, and warming-induced increased CH4 flux densities partially offset by a reduction in wetland extent.
DOI:10.1111/gcb.13215URLPMID:26728638 [本文引用: 1]
Increasing temperatures and atmospheric CO2 concentrations will affect tree carbon fluxes, generating potential feedbacks between forests and the global climate system. We studied how elevated temperatures and CO2 impacted leaf carbon dynamics in Norway spruce (Picea abies), a dominant northern forest species, to improve predictions of future photosynthetic and respiratory fluxes from high-latitude conifers. Seedlings were grown under ambient (AC, c. 435 mumol mol(-1) ) or elevated (EC, 750 mumol mol(-1) ) CO2 concentrations at ambient, +4 degrees C, or +8 degrees C growing temperatures. Photosynthetic rates (Asat ) were high in +4 degrees C/EC seedlings and lowest in +8 degrees C spruce, implying that moderate, but not extreme, climate change may stimulate carbon uptake. Asat , dark respiration (Rdark ), and light respiration (Rlight ) rates acclimated to temperature, but not CO2 : the thermal optimum of Asat increased, and Rdark and Rlight were suppressed under warming. In all treatments, the Q10 of Rlight (the relative increase in respiration for a 10 degrees C increase in leaf temperature) was 35% higher than the Q10 of Rdark , so the ratio of Rlight to Rdark increased with rising leaf temperature. However, across all treatments and a range of 10-40 degrees C leaf temperatures, a consistent relationship between Rlight and Rdark was found, which could be used to model Rlight in future climates. Acclimation reduced daily modeled respiratory losses from warm-grown seedlings by 22-56%. When Rlight was modeled as a constant fraction of Rdark , modeled daily respiratory losses were 11-65% greater than when using measured values of Rlight . Our findings highlight the impact of acclimation to future climates on predictions of carbon uptake and losses in northern trees, in particular the need to model daytime respiratory losses from direct measurements of Rlight or appropriate relationships with Rdark .
DOI:10.1038/nature16476URLPMID:26700807 [本文引用: 1]
Phenotypic traits and their associated trade-offs have been shown to have globally consistent effects on individual plant physiological functions, but how these effects scale up to influence competition, a key driver of community assembly in terrestrial vegetation, has remained unclear. Here we use growth data from more than 3 million trees in over 140,000 plots across the world to show how three key functional traits--wood density, specific leaf area and maximum height--consistently influence competitive interactions. Fast maximum growth of a species was correlated negatively with its wood density in all biomes, and positively with its specific leaf area in most biomes. Low wood density was also correlated with a low ability to tolerate competition and a low competitive effect on neighbours, while high specific leaf area was correlated with a low competitive effect. Thus, traits generate trade-offs between performance with competition versus performance without competition, a fundamental ingredient in the classical hypothesis that the coexistence of plant species is enabled via differentiation in their successional strategies. Competition within species was stronger than between species, but an increase in trait dissimilarity between species had little influence in weakening competition. No benefit of dissimilarity was detected for specific leaf area or wood density, and only a weak benefit for maximum height. Our trait-based approach to modelling competition makes generalization possible across the forest ecosystems of the world and their highly diverse species composition.
DOI:10.1093/aob/mcl114URLPMID:16769731 [本文引用: 1]
BACKGROUND: Global phosphorus (P) reserves are being depleted, with half-depletion predicted to occur between 2040 and 2060. Most of the P applied in fertilizers may be sorbed by soil, and not be available for plants lacking specific adaptations. On the severely P-impoverished soils of south-western Australia and the Cape region in South Africa, non-mycorrhizal species exhibit highly effective adaptations to acquire P. A wide range of these non-mycorrhizal species, belonging to two monocotyledonous and eight dicotyledonous families, produce root clusters. Non-mycorrhizal species with root clusters appear to be particularly effective at accessing P when its availability is extremely low. SCOPE: There is a need to develop crops that are highly effective at acquiring inorganic P (Pi) from P-sorbing soils. Traits such as those found in non-mycorrhizal root-cluster-bearing species in Australia, South Africa and other P-impoverished environments are highly desirable for future crops. Root clusters combine a specialized structure with a specialized metabolism. Native species with such traits could be domesticated or crossed with existing crop species. An alternative approach would be to develop future crops with root clusters based on knowledge of the genes involved in development and functioning of root clusters. CONCLUSIONS: Root clusters offer enormous potential for future research of both a fundamental and a strategic nature. New discoveries of the development and functioning of root clusters in both monocotyledonous and dicotyledonous families are essential to produce new crops with superior P-acquisition traits.
DOI:10.1002/ecy.1975URLPMID:28766706 [本文引用: 1]
Large uncertainties exist in carbon (C)-climate feedback in permafrost regions, partly due to an insufficient understanding of warming effects on nutrient availabilities and their subsequent impacts on vegetation C sequestration. Although a warming climate may promote a substantial release of soil C to the atmosphere, a warming-induced increase in soil nutrient availability may enhance plant productivity, thus offsetting C loss from microbial respiration. Here, we present evidence that the positive temperature effect on carbon dioxide (CO2 ) fluxes may be weakened by reduced plant nitrogen (N) and phosphorous (P) concentrations in a Tibetan permafrost ecosystem. Although experimental warming initially enhanced ecosystem CO2 uptake, the increased rate disappeared after the period of peak plant growth during the early growing season, even though soil moisture was not a limiting factor in this swamp meadow ecosystem. We observed that warming did not significantly affect soil extractable N or P during the period of peak growth, but decreased both N and P concentrations in the leaves of dominant plant species, likely caused by accelerated plant senescence in the warmed plots. The attenuated warming effect on CO2 assimilation during the late growing season was associated with lowered leaf N and P concentrations. These findings suggest that warming-mediated nutrient changes may not always benefit ecosystem C uptake in permafrost regions, making our ability to predict the C balance in these warming-sensitive ecosystems more challenging than previously thought.
DOI:10.1007/s10533-013-9948-8URL [本文引用: 1]
Global ecosystem models may require microbial components to accurately predict feedbacks between climate warming and soil decomposition, but it is unclear what parameters and levels of complexity are ideal for scaling up to the globe. Here we conducted a model comparison using a conventional model with first-order decay and three microbial models of increasing complexity that simulate short- to long-term soil carbon dynamics. We focused on soil carbon responses to microbial carbon use efficiency (CUE) and temperature. Three scenarios were implemented in all models: constant CUE (held at 0.31), varied CUE (-0.016 A degrees C-1), and 50 % acclimated CUE (-0.008 A degrees C-1). Whereas the conventional model always showed soil carbon losses with increasing temperature, the microbial models each predicted a temperature threshold above which warming led to soil carbon gain. The location of this threshold depended on CUE scenario, with higher temperature thresholds under the acclimated and constant scenarios. This result suggests that the temperature sensitivity of CUE and the structure of the soil carbon model together regulate the long-term soil carbon response to warming. Equilibrium soil carbon stocks predicted by the microbial models were much less sensitive to changing inputs compared to the conventional model. Although many soil carbon dynamics were similar across microbial models, the most complex model showed less pronounced oscillations. Thus, adding model complexity (i.e. including enzyme pools) could improve the mechanistic representation of soil carbon dynamics during the transient phase in certain ecosystems. This study suggests that model structure and CUE parameterization should be carefully evaluated when scaling up microbial models to ecosystems and the globe.
DOI:10.1038/s41467-018-05667-7URLPMID:30093611 [本文引用: 1]
Increases in carbon (C) inputs to soil can replenish soil organic C (SOC) through various mechanisms. However, recent studies have suggested that the increased C input can also stimulate the decomposition of old SOC via priming. Whether the loss of old SOC by priming can override C replenishment has not been rigorously examined. Here we show, through data-model synthesis, that the magnitude of replenishment is greater than that of priming, resulting in a net increase in SOC by a mean of 32% of the added new C. The magnitude of the net increase in SOC is positively correlated with the nitrogen-to-C ratio of the added substrates. Additionally, model evaluation indicates that a two-pool interactive model is a parsimonious model to represent the SOC decomposition with priming and replenishment. Our findings suggest that increasing C input to soils likely promote SOC accumulation despite the enhanced decomposition of old C via priming.
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URLPMID:20609113 [本文引用: 1]
DOI:10.1111/gcb.13311URLPMID:27061925 [本文引用: 1]
The timing of the end of the vegetation growing season (EOS) plays a key role in terrestrial ecosystem carbon and nutrient cycles. Autumn phenology is, however, still poorly understood, and previous studies generally focused on few species or were very limited in scale. In this study, we applied four methods to extract EOS dates from NDVI records between 1982 and 2011 for the Northern Hemisphere, and determined the temporal correlations between EOS and environmental factors (i.e., temperature, precipitation and insolation), as well as the correlation between spring and autumn phenology, using partial correlation analyses. Overall, we observed a trend toward later EOS in ~70% of the pixels in Northern Hemisphere, with a mean rate of 0.18 +/- 0.38 days yr(-1) . Warming preseason temperature was positively associated with the rate of EOS in most of our study area, except for arid/semi-arid regions, where the precipitation sum played a dominant positive role. Interestingly, increased preseason insolation sum might also lead to a later date of EOS. In addition to the climatic effects on EOS, we found an influence of spring vegetation green-up dates on EOS, albeit biome dependent. Our study, therefore, suggests that both environmental factors and spring phenology should be included in the modeling of EOS to improve the predictions of autumn phenology as well as our understanding of the global carbon and nutrient balances.
DOI:10.1890/12-0279.1URLPMID:23687898 [本文引用: 1]
Global warming potentially alters the terrestrial carbon (C) cycle, likely feeding back to further climate warming. However, how the ecosystem C cycle responds and feeds back to warming remains unclear. Here we used a meta-analysis approach to quantify the response ratios of 18 variables of the ecosystem C cycle to experimental warming and evaluated ecosystem C-cycle feedback to climate warming. Our results showed that warming stimulated gross ecosystem photosynthesis (GEP) by 15.7%, net primary production (NPP) by 4.4%, and plant C pools from above- and belowground parts by 6.8% and 7.0%, respectively. Experimental warming accelerated litter mass loss by 6.8%, soil respiration by 9.0%, and dissolved organic C leaching by 12.1%. In addition, the responses of some of those variables to experimental warming differed among the ecosystem types. Our results demonstrated that the stimulation of plant-derived C influx basically offset the increase in warming-induced efflux and resulted in insignificant changes in litter and soil C content, indicating that climate warming may not trigger strong positive C-climate feedback from terrestrial ecosystems. Moreover, the increase in plant C storage together with the slight but not statistically significant decrease of net ecosystem exchange (NEE) across ecosystems suggests that terrestrial ecosystems might be a weak C sink rather than a C source under global climate warming. Our results are also potentially useful for parameterizing and benchmarking land surface models in terms of C cycle responses to climate warming.
URLPMID:11675783 [本文引用: 2]
DOI:10.1890/08-0561.1URLPMID:19425417 [本文引用: 2]
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DOI:10.3390/rs9030188URL [本文引用: 2]
DOI:10.1038/nature25783URLPMID:29466331 [本文引用: 1]
Plant roots have greatly diversified in form and function since the emergence of the first land plants, but the global organization of functional traits in roots remains poorly understood. Here we analyse a global dataset of 10 functionally important root traits in metabolically active first-order roots, collected from 369 species distributed across the natural plant communities of 7 biomes. Our results identify a high degree of organization of root traits across species and biomes, and reveal a pattern that differs from expectations based on previous studies of leaf traits. Root diameter exerts the strongest influence on root trait variation across plant species, growth forms and biomes. Our analysis suggests that plants have evolved thinner roots since they first emerged in land ecosystems, which has enabled them to markedly improve their efficiency of soil exploration per unit of carbon invested and to reduce their dependence on symbiotic mycorrhizal fungi. We also found that diversity in root morphological traits is greatest in the tropics, where plant diversity is highest and many ancestral phylogenetic groups are preserved. Diversity in root morphology declines sharply across the sequence of tropical, temperate and desert biomes, presumably owing to changes in resource supply caused by seasonally inhospitable abiotic conditions. Our results suggest that root traits have evolved along a spectrum bounded by two contrasting strategies of root life: an ancestral 'conservative' strategy in which plants with thick roots depend on symbiosis with mycorrhizal fungi for soil resources and a more-derived 'opportunistic' strategy in which thin roots enable plants to more efficiently leverage photosynthetic carbon for soil exploration. These findings imply that innovations of belowground traits have had an important role in preparing plants to colonize new habitats, and in generating biodiversity within and across biomes.
DOI:10.1038/ncomms15378URLPMID:28488673
Anthropogenic climate change has emerged as a critical environmental problem, prompting frequent investigations into its consequences for various ecological systems. Few studies, however, have explored the effect of climate change on ecological stability and the underlying mechanisms. We conduct a field experiment to assess the influence of warming and altered precipitation on the temporal stability of plant community biomass in an alpine grassland located on the Tibetan Plateau. We find that whereas precipitation alteration does not influence biomass temporal stability, warming lowers stability through reducing the degree of species asynchrony. Importantly, biomass temporal stability is not influenced by plant species diversity, but is largely determined by the temporal stability of dominant species and asynchronous population dynamics among the coexisting species. Our findings suggest that ongoing and future climate change may alter stability properties of ecological communities, potentially hindering their ability to provide ecosystem services for humanity.
DOI:10.1111/nph.14189URLPMID:27768811 [本文引用: 1]
Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation. We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300 m elevation transect in Peru. Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in CUE implies that the proportion of photosynthate allocated to autotrophic respiration is not sensitive to temperature. Rather than a gradual linear decline in productivity, there is some limited but nonconclusive evidence of a sharp transition in NPP between submontane and montane forests, which may be caused by cloud immersion effects within the cloud forest zone. Leaf-level photosynthetic parameters do not decline with elevation, implying that nutrient limitation does not restrict photosynthesis at high elevations. Our data demonstrate the potential of whole carbon budget perspectives to provide a deeper understanding of controls on ecosystem functioning and carbon cycling.
DOI:10.1111/fec.2006.20.issue-6URL [本文引用: 1]
DOI:10.1111/nph.15027URLPMID:29451313 [本文引用: 1]
Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.
DOI:10.1111/j.1365-2486.2012.02708.xURL [本文引用: 1]
DOI:10.1111/gcb.13268URLPMID:26946185 [本文引用: 1]
The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca ), particularly under nutrient-limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient- and water-limited woodland presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a postexperiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25% across models. The simulated reduction of NPP during a low-rainfall year also varied widely, from 24 to 70%. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutrient uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements.
DOI:10.1038/nclimate2621URL [本文引用: 3]
DOI:10.2307/1936576URL [本文引用: 1]
DOI:10.1073/pnas.1018189108URL [本文引用: 1]
Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon-nitrogen interactions in atmosphere-ocean-land earth system models to accurately simulate land feedbacks to the climate system.
DOI:10.1126/science.aan2874URLPMID:28983050 [本文引用: 3]
In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.
DOI:10.1126/science.1074153URLPMID:12481133 [本文引用: 1]
In a decade-long soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon and nitrogen cycling in order to investigate the consequences of these changes for the climate system. Here we show that whereas soil warming accelerates soil organic matter decay and carbon dioxide fluxes to the atmosphere, this response is small and short-lived for a mid-latitude forest, because of the limited size of the labile soil carbon pool. We also show that warming increases the availability of mineral nitrogen to plants. Because plant growth in many mid-latitude forests is nitrogen-limited, warming has the potential to indirectly stimulate enough carbon storage in plants to at least compensate for the carbon losses from soils. Our results challenge assumptions made in some climate models that lead to projections of large long-term releases of soil carbon in response to warming of forest ecosystems.
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DOI:10.1023/A:1022880418362URL [本文引用: 1]
DOI:10.1111/gcb.2006.12.issue-10URL [本文引用: 1]
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DOI:10.1016/j.soilbio.2017.10.031URL [本文引用: 1]
DOI:10.1126/sciadv.1602781URLPMID:28508070 [本文引用: 1]
Predicted changes in the intensity and frequency of climate extremes urge a better mechanistic understanding of the stress response of microbially mediated carbon (C) and nutrient cycling processes. We analyzed the resistance and resilience of microbial C, nitrogen (N), and phosphorus (P) cycling processes and microbial community composition in decomposing plant litter to transient, but severe, temperature disturbances, namely, freeze-thaw and heat. Disturbances led temporarily to a more rapid cycling of C and N but caused a down-regulation of P cycling. In contrast to the fast recovery of the initially stimulated C and N processes, we found a slow recovery of P mineralization rates, which was not accompanied by significant changes in community composition. The functional and structural responses to the two distinct temperature disturbances were markedly similar, suggesting that direct negative physical effects and costs associated with the stress response were comparable. Moreover, the stress response of extracellular enzyme activities, but not that of intracellular microbial processes (for example, respiration or N mineralization), was dependent on the nutrient content of the resource through its effect on microbial physiology and community composition. Our laboratory study provides novel insights into the mechanisms of microbial functional stress responses that can serve as a basis for field studies and, in particular, illustrates the need for a closer integration of microbial C-N-P interactions into climate extremes research.
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DOI:10.1088/1748-9326/6/4/045509URL [本文引用: 1]
DOI:10.1038/386698a0URL [本文引用: 1]
DOI:10.1126/science.1082750URLPMID:12791990
Recent climatic changes have enhanced plant growth in northern mid-latitudes and high latitudes. However, a comprehensive analysis of the impact of global climatic changes on vegetation productivity has not before been expressed in the context of variable limiting factors to plant growth. We present a global investigation of vegetation responses to climatic changes by analyzing 18 years (1982 to 1999) of both climatic data and satellite observations of vegetation activity. Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.
DOI:10.1111/ele.12591URLPMID:26932540 [本文引用: 1]
Nitrogen (N) deposition is impacting the services that ecosystems provide to humanity. However, the mechanisms determining impacts on the N cycle are not fully understood. To explore the mechanistic underpinnings of N impacts on N cycle processes, we reviewed and synthesised recent progress in ecosystem N research through empirical studies, conceptual analysis and model simulations. Experimental and observational studies have revealed that the stimulation of plant N uptake and soil retention generally diminishes as N loading increases, while dissolved and gaseous losses of N occur at low N availability but increase exponentially and become the dominant fate of N at high loading rates. The original N saturation hypothesis emphasises sequential N saturation from plant uptake to soil retention before N losses occur. However, biogeochemical models that simulate simultaneous competition for soil N substrates by multiple processes match the observed patterns of N losses better than models based on sequential competition. To enable better prediction of terrestrial N cycle responses to N loading, we recommend that future research identifies the response functions of different N processes to substrate availability using manipulative experiments, and incorporates the measured N saturation response functions into conceptual, theoretical and quantitative analyses.
DOI:10.1111/j.1469-8137.2012.04095.xURL [本文引用: 3]
It is well established that individual organisms can acclimate and adapt to temperature to optimize their functioning. However, thermal optimization of ecosystems, as an assemblage of organisms, has not been examined at broad spatial and temporal scales. Here, we compiled data from 169 globally distributed sites of eddy covariance and quantified the temperature response functions of net ecosystem exchange (NEE), an ecosystem-level property, to determine whether NEE shows thermal optimality and to explore the underlying mechanisms. We found that the temperature response of NEE followed a peak curve, with the optimum temperature (corresponding to the maximum magnitude of NEE) being positively correlated with annual mean temperature over years and across sites. Shifts of the optimum temperature of NEE were mostly a result of temperature acclimation of gross primary productivity (upward shift of optimum temperature) rather than changes in the temperature sensitivity of ecosystem respiration. Ecosystem-level thermal optimality is a newly revealed ecosystem property, presumably reflecting associated evolutionary adaptation of organisms within ecosystems, and has the potential to significantly regulate ecosystemclimate change feedbacks. The thermal optimality of NEE has implications for understanding fundamental properties of ecosystems in changing environments and benchmarking global models.
URLPMID:26249015 [本文引用: 1]
DOI:10.1073/pnas.1305533110URLPMID:23901098 [本文引用: 1]
Climate change may disrupt interspecies phenological synchrony, with adverse consequences to ecosystem functioning. We present here a 40-y-long time series on 10,425 dates that were systematically collected in a single Russian locality for 97 plant, 78 bird, 10 herptile, 19 insect, and 9 fungal phenological events, as well as for 77 climatic events related to temperature, precipitation, snow, ice, and frost. We show that species are shifting their phenologies at dissimilar rates, partly because they respond to different climatic factors, which in turn are shifting at dissimilar rates. Plants have advanced their spring phenology even faster than average temperature has increased, whereas migratory birds have shown more divergent responses and shifted, on average, less than plants. Phenological events of birds and insects were mainly triggered by climate cues (variation in temperature and snow and ice cover) occurring over the course of short periods, whereas many plants, herptiles, and fungi were affected by long-term climatic averages. Year-to-year variation in plants, herptiles, and insects showed a high degree of synchrony, whereas the phenological timing of fungi did not correlate with any other taxonomic group. In many cases, species that are synchronous in their year-to-year dynamics have also shifted in congruence, suggesting that climate change may have disrupted phenological synchrony less than has been previously assumed. Our results illustrate how a multidimensional change in the physical environment has translated into a community-level change in phenology.
URLPMID:29981157 [本文引用: 1]
DOI:10.1111/gcb.2007.13.issue-9URL [本文引用: 1]
DOI:10.1038/nature01286URLPMID:12511946 [本文引用: 1]
Causal attribution of recent biological trends to climate change is complicated because non-climatic influences dominate local, short-term biological changes. Any underlying signal from climate change is likely to be revealed by analyses that seek systematic trends across diverse species and geographic regions; however, debates within the Intergovernmental Panel on Climate Change (IPCC) reveal several definitions of a 'systematic trend'. Here, we explore these differences, apply diverse analyses to more than 1,700 species, and show that recent biological trends match climate change predictions. Global meta-analyses documented significant range shifts averaging 6.1 km per decade towards the poles (or metres per decade upward), and significant mean advancement of spring events by 2.3 days per decade. We define a diagnostic fingerprint of temporal and spatial 'sign-switching' responses uniquely predicted by twentieth century climate trends. Among appropriate long-term/large-scale/multi-species data sets, this diagnostic fingerprint was found for 279 species. This suite of analyses generates 'very high confidence' (as laid down by the IPCC) that climate change is already affecting living systems.
DOI:10.1126/science.1219033URLPMID:22517860 [本文引用: 1]
In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region.
URLPMID:27078564 [本文引用: 1]
DOI:10.1073/pnas.0403720101URLPMID:15226500 [本文引用: 1]
The impact of projected global warming on crop yields has been evaluated by indirect methods using simulation models. Direct studies on the effects of observed climate change on crop growth and yield could provide more accurate information for assessing the impact of climate change on crop production. We analyzed weather data at the International Rice Research Institute Farm from 1979 to 2003 to examine temperature trends and the relationship between rice yield and temperature by using data from irrigated field experiments conducted at the International Rice Research Institute Farm from 1992 to 2003. Here we report that annual mean maximum and minimum temperatures have increased by 0.35 degrees C and 1.13 degrees C, respectively, for the period 1979-2003 and a close linkage between rice grain yield and mean minimum temperature during the dry cropping season (January to April). Grain yield declined by 10% for each 1 degrees C increase in growing-season minimum temperature in the dry season, whereas the effect of maximum temperature on crop yield was insignificant. This report provides a direct evidence of decreased rice yields from increased nighttime temperature associated with global warming.
DOI:10.1038/nature12434URLPMID:24005415 [本文引用: 2]
Temperature data over the past five decades show faster warming of the global land surface during the night than during the day. This asymmetric warming is expected to affect carbon assimilation and consumption in plants, because photosynthesis in most plants occurs during daytime and is more sensitive to the maximum daily temperature, Tmax, whereas plant respiration occurs throughout the day and is therefore influenced by both Tmax and the minimum daily temperature, Tmin. Most studies of the response of terrestrial ecosystems to climate warming, however, ignore this asymmetric forcing effect on vegetation growth and carbon dioxide (CO2) fluxes. Here we analyse the interannual covariations of the satellite-derived normalized difference vegetation index (NDVI, an indicator of vegetation greenness) with Tmax and Tmin over the Northern Hemisphere. After removing the correlation between Tmax and Tmin, we find that the partial correlation between Tmax and NDVI is positive in most wet and cool ecosystems over boreal regions, but negative in dry temperate regions. In contrast, the partial correlation between Tmin and NDVI is negative in boreal regions, and exhibits a more complex behaviour in dry temperate regions. We detect similar patterns in terrestrial net CO2 exchange maps obtained from a global atmospheric inversion model. Additional analysis of the long-term atmospheric CO2 concentration record of the station Point Barrow in Alaska suggests that the peak-to-peak amplitude of CO2 increased by 23 +/- 11% for a +1 degrees C anomaly in Tmax from May to September over lands north of 51 degrees N, but decreased by 28 +/- 14% for a +1 degrees C anomaly in Tmin. These lines of evidence suggest that asymmetric diurnal warming, a process that is currently not taken into account in many global carbon cycle models, leads to a divergent response of Northern Hemisphere vegetation growth and carbon sequestration to rising temperatures.
DOI:10.1007/s10021-018-0310-9URL [本文引用: 1]
URLPMID:24343268 [本文引用: 1]
DOI:10.1016/j.atmosres.2015.05.014URL [本文引用: 1]
[本文引用: 1]
DOI:10.1038/ncomms6018URLPMID:25318638 [本文引用: 1]
Satellite-derived Normalized Difference Vegetation Index (NDVI), a proxy of vegetation productivity, is known to be correlated with temperature in northern ecosystems. This relationship, however, may change over time following alternations in other environmental factors. Here we show that above 30 degrees N, the strength of the relationship between the interannual variability of growing season NDVI and temperature (partial correlation coefficient RNDVI-GT) declined substantially between 1982 and 2011. This decrease in RNDVI-GT is mainly observed in temperate and arctic ecosystems, and is also partly reproduced by process-based ecosystem model results. In the temperate ecosystem, the decrease in RNDVI-GT coincides with an increase in drought. In the arctic ecosystem, it may be related to a nonlinear response of photosynthesis to temperature, increase of hot extreme days and shrub expansion over grass-dominated tundra. Our results caution the use of results from interannual time scales to constrain the decadal response of plants to ongoing warming.
DOI:10.1038/ncomms7911URLPMID:25903224 [本文引用: 1]
Recent warming significantly advanced leaf onset in the northern hemisphere. This signal cannot be accurately reproduced by current models parameterized by daily mean temperature (T(mean)). Here using in situ observations of leaf unfolding dates (LUDs) in Europe and the United States, we show that the interannual anomalies of LUD during 1982-2011 are triggered by daytime (Tmax) more than by nighttime temperature (T(min)). Furthermore, an increase of 1 degrees C in Tmax would advance LUD by 4.7 days in Europe and 4.3 days in the United States, more than the conventional temperature sensitivity estimated from T(mean). The triggering role of Tmax, rather than the T(min) or T(mean) variable, is also supported by analysis of the large-scale patterns of satellite-derived vegetation green-up in spring in the northern hemisphere (>30 degrees N). Our results suggest a new conceptual framework of leaf onset using daytime temperature to improve the performance of phenology modules in current Earth system models.
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[本文引用: 1]
DOI:10.1126/science.aal1319URLPMID:28280251 [本文引用: 1]
Soil organic carbon harbors three times as much carbon as Earth's atmosphere, and its decomposition is a potentially large climate change feedback and major source of uncertainty in climate projections. The response of whole-soil profiles to warming has not been tested in situ. In a deep warming experiment in mineral soil, we found that CO2 production from all soil depths increased with 4 degrees C warming; annual soil respiration increased by 34 to 37%. All depths responded to warming with similar temperature sensitivities, driven by decomposition of decadal-aged carbon. Whole-soil warming reveals a larger soil respiration response than many in situ experiments (most of which only warm the surface soil) and models.
URLPMID:32064310 [本文引用: 1]
[本文引用: 1]
URL [本文引用: 1]
DOI:10.1126/science.aas9313URLPMID:29674593 [本文引用: 1]
Theory predicts and evidence shows that plant species that use the C4 photosynthetic pathway (C4 species) are less responsive to elevated carbon dioxide (eCO2) than species that use only the C3 pathway (C3 species). We document a reversal from this expected C3-C4 contrast. Over the first 12 years of a 20-year free-air CO2 enrichment experiment with 88 C3 or C4 grassland plots, we found that biomass was markedly enhanced at eCO2 relative to ambient CO2 in C3 but not C4 plots, as expected. During the subsequent 8 years, the pattern reversed: Biomass was markedly enhanced at eCO2 relative to ambient CO2 in C4 but not C3 plots. Soil net nitrogen mineralization rates, an index of soil nitrogen supply, exhibited a similar shift: eCO2 first enhanced but later depressed rates in C3 plots, with the opposite true in C4 plots, partially explaining the reversal of the eCO2 biomass response. These findings challenge the current C3-C4eCO2 paradigm and show that even the best-supported short-term drivers of plant response to global change might not predict long-term results.
DOI:10.1038/s41586-018-0582-4URLPMID:30283137 [本文引用: 1]
Climate warming will influence photosynthesis via thermal effects and by altering soil moisture(1-11). Both effects may be important for the vast areas of global forests that fluctuate between periods when cool temperatures limit photosynthesis and periods when soil moisture may be limiting to carbon gain(4-6,9-11). Here we show that the effects of climate warming flip from positive to negative as southern boreal forests transition from rainy to modestly dry periods during the growing season. In a three-year open-air warming experiment with juveniles of 11 temperate and boreal tree species, an increase of 3.4 degrees C in temperature increased light-saturated net photosynthesis and leaf diffusive conductance on average on the one-third of days with the wettest soils. In all 11 species, leaf diffusive conductance and, as a result, light-saturated net photosynthesis decreased during dry spells, and did so more sharply in warmed plants than in plants at ambient temperatures. Consequently, across the 11 species, warming reduced light-saturated net photosynthesis on the two-thirds of days with driest soils. Thus, low soil moisture may reduce, or even reverse, the potential benefits of climate warming on photosynthesis in mesic, seasonally cold environments, both during drought and in regularly occurring, modestly dry periods during the growing season.
DOI:10.1073/pnas.94.25.13730URLPMID:9391094 [本文引用: 1]
Despite striking differences in climate, soils, and evolutionary history among diverse biomes ranging from tropical and temperate forests to alpine tundra and desert, we found similar interspecific relationships among leaf structure and function and plant growth in all biomes. Our results thus demonstrate convergent evolution and global generality in plant functioning, despite the enormous diversity of plant species and biomes. For 280 plant species from two global data sets, we found that potential carbon gain (photosynthesis) and carbon loss (respiration) increase in similar proportion with decreasing leaf life-span, increasing leaf nitrogen concentration, and increasing leaf surface area-to-mass ratio. Productivity of individual plants and of leaves in vegetation canopies also changes in constant proportion to leaf life-span and surface area-to-mass ratio. These global plant functional relationships have significant implications for global scale modeling of vegetation-atmosphere CO2 exchange.
URLPMID:30089905 [本文引用: 1]
DOI:10.1038/nature15539URLPMID:26595275 [本文引用: 1]
Drought threatens tropical rainforests over seasonal to decadal timescales, but the drivers of tree mortality following drought remain poorly understood. It has been suggested that reduced availability of non-structural carbohydrates (NSC) critically increases mortality risk through insufficient carbon supply to metabolism ('carbon starvation'). However, little is known about how NSC stores are affected by drought, especially over the long term, and whether they are more important than hydraulic processes in determining drought-induced mortality. Using data from the world's longest-running experimental drought study in tropical rainforest (in the Brazilian Amazon), we test whether carbon starvation or deterioration of the water-conducting pathways from soil to leaf trigger tree mortality. Biomass loss from mortality in the experimentally droughted forest increased substantially after >10 years of reduced soil moisture availability. The mortality signal was dominated by the death of large trees, which were at a much greater risk of hydraulic deterioration than smaller trees. However, we find no evidence that the droughted trees suffered carbon starvation, as their NSC concentrations were similar to those of non-droughted trees, and growth rates did not decline in either living or dying trees. Our results indicate that hydraulics, rather than carbon starvation, triggers tree death from drought in tropical rainforest.
DOI:10.1007/s11104-010-0391-5URL [本文引用: 3]
Despite their low carbon (C) content, most subsoil horizons contribute to more than half of the total soil C stocks, and therefore need to be considered in the global C cycle. Until recently, the properties and dynamics of C in deep soils was largely ignored. The aim of this review is to synthesize literature concerning the sources, composition, mechanisms of stabilisation and destabilization of soil organic matter (SOM) stored in subsoil horizons. Organic C input into subsoils occurs in dissolved form (DOC) following preferential flow pathways, as aboveground or root litter and exudates along root channels and/or through bioturbation. The relative importance of these inputs for subsoil C distribution and dynamics still needs to be evaluated. Generally, C in deep soil horizons is characterized by high mean residence times of up to several thousand years. With few exceptions, the carbon-to-nitrogen (C/N) ratio is decreasing with soil depth, while the stable C and N isotope ratios of SOM are increasing, indicating that organic matter (OM) in deep soil horizons is highly processed. Several studies suggest that SOM in subsoils is enriched in microbial-derived C compounds and depleted in energy-rich plant material compared to topsoil SOM. However, the chemical composition of SOM in subsoils is soil-type specific and greatly influenced by pedological processes. Interaction with the mineral phase, in particular amorphous iron (Fe) and aluminum (Al) oxides was reported to be the main stabilization mechanism in acid and near neutral soils. In addition, occlusion within soil aggregates has been identified to account for a great proportion of SOM preserved in subsoils. Laboratory studies have shown that the decomposition of subsoil C with high residence times could be stimulated by addition of labile C. Other mechanisms leading to destabilisation of SOM in subsoils include disruption of the physical structure and nutrient supply to soil microorganisms. One of the most important factors leading to protection of SOM in subsoils may be the spatial separation of SOM, microorganisms and extracellular enzyme activity possibly related to the heterogeneity of C input. As a result of the different processes, stabilized SOM in subsoils is horizontally stratified. In order to better understand deep SOM dynamics and to include them into soil C models, quantitative information about C fluxes resulting from C input, stabilization and destabilization processes at the field scale are necessary.
URLPMID:30166559 [本文引用: 1]
DOI:10.1111/j.1365-3040.2007.01682.xURLPMID:17661749 [本文引用: 2]
DOI:10.1111/(ISSN)1365-2486URL [本文引用: 2]
[本文引用: 1]
DOI:10.1038/nature14338URLPMID:25855454 [本文引用: 1]
Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.
DOI:10.1038/nature08031URLPMID:19478781 [本文引用: 1]
Permafrost soils in boreal and Arctic ecosystems store almost twice as much carbon as is currently present in the atmosphere. Permafrost thaw and the microbial decomposition of previously frozen organic carbon is considered one of the most likely positive climate feedbacks from terrestrial ecosystems to the atmosphere in a warmer world. The rate of carbon release from permafrost soils is highly uncertain, but it is crucial for predicting the strength and timing of this carbon-cycle feedback effect, and thus how important permafrost thaw will be for climate change this century and beyond. Sustained transfers of carbon to the atmosphere that could cause a significant positive feedback to climate change must come from old carbon, which forms the bulk of the permafrost carbon pool that accumulated over thousands of years. Here we measure net ecosystem carbon exchange and the radiocarbon age of ecosystem respiration in a tundra landscape undergoing permafrost thaw to determine the influence of old carbon loss on ecosystem carbon balance. We find that areas that thawed over the past 15 years had 40 per cent more annual losses of old carbon than minimally thawed areas, but had overall net ecosystem carbon uptake as increased plant growth offset these losses. In contrast, areas that thawed decades earlier lost even more old carbon, a 78 per cent increase over minimally thawed areas; this old carbon loss contributed to overall net ecosystem carbon release despite increased plant growth. Our data document significant losses of soil carbon with permafrost thaw that, over decadal timescales, overwhelms increased plant carbon uptake at rates that could make permafrost a large biospheric carbon source in a warmer world.
DOI:10.1105/tpc.16.00113URL [本文引用: 1]
DOI:10.1641/0006-3568(2000)050[0871:GWATEA]2.0.CO;2URL [本文引用: 1]
DOI:10.1073/pnas.0605642104URLPMID:17182748 [本文引用: 1]
Because the flowering and fruiting phenology of plants is sensitive to environmental cues such as temperature and moisture, climate change is likely to alter community-level patterns of reproductive phenology. Here we report a previously unreported phenomenon: experimental warming advanced flowering and fruiting phenology for species that began to flower before the peak of summer heat but delayed reproduction in species that started flowering after the peak temperature in a tallgrass prairie in North America. The warming-induced divergence of flowering and fruiting toward the two ends of the growing season resulted in a gap in the staggered progression of flowering and fruiting in the community during the middle of the season. A double precipitation treatment did not significantly affect flowering and fruiting phenology. Variation among species in the direction and magnitude of their response to warming caused compression and expansion of the reproductive periods of different species, changed the amount of overlap between the reproductive phases, and created possibilities for an altered selective environment to reshape communities in a future warmed world.
DOI:10.1038/s41467-018-04526-9URLPMID:29867087 [本文引用: 2]
Large model uncertainty in projected future soil carbon (C) dynamics has been well documented. However, our understanding of the sources of this uncertainty is limited. Here we quantify the uncertainties arising from model parameters, structures and their interactions, and how those uncertainties propagate through different models to projections of future soil carbon stocks. Both the vertically resolved model and the microbial explicit model project much greater uncertainties to climate change than the conventional soil C model, with both positive and negative C-climate feedbacks, whereas the conventional model consistently predicts positive soil C-climate feedback. Our findings suggest that diverse model structures are necessary to increase confidence in soil C projection. However, the larger uncertainty in the complex models also suggests that we need to strike a balance between model complexity and the need to include diverse model structures in order to forecast soil C dynamics with high confidence and low uncertainty.
DOI:10.1111/1365-2745.12449URL [本文引用: 1]
DOI:10.1007/s00442-014-3159-4URLPMID:25481817 [本文引用: 1]
Respiration is instrumental for survival and growth of plants, but increasing costs of maintenance processes with warming have the potential to change the balance between photosynthetic carbon uptake and respiratory carbon release from leaves. Climate warming may cause substantial increases of leaf respiratory carbon fluxes, which would further impact the carbon balance of terrestrial vegetation. However, downregulation of respiratory physiology via thermal acclimation may mitigate this impact. We have conducted a meta-analysis with data collected from 43 independent studies to assess quantitatively the thermal acclimation capacity of leaf dark respiration to warming of terrestrial plant species from across the globe. In total, 282 temperature contrasts were included in the meta-analysis, representing 103 species of forbs, graminoids, shrubs, trees and lianas native to arctic, boreal, temperate and tropical ecosystems. Acclimation to warming was found to decrease respiration at a set temperature in the majority of the observations, regardless of the biome of origin and growth form, but respiration was not completely homeostatic across temperatures in the majority of cases. Leaves that developed at a new temperature had a greater capacity for acclimation than those transferred to a new temperature. We conclude that leaf respiration of most terrestrial plants can acclimate to gradual warming, potentially reducing the magnitude of the positive feedback between climate and the carbon cycle in a warming world. More empirical data are, however, needed to improve our understanding of interspecific variation in thermal acclimation capacity, and to better predict patterns in respiratory carbon fluxes both within and across biomes in the face of ongoing global warming.
DOI:10.1111/j.1365-2745.2011.01833.xURL [本文引用: 1]
1. Climate extremes, such as severe drought, heat waves and periods of heavy rainfall, can have profound consequences for ecological systems and for human welfare. Global climate change is expected to increase both the frequency and the intensity of climate extremes and there is an urgent need to understand their ecological consequences.2. Major challenges for advancing our understanding of the ecological consequences of climate extremes include setting a climatic baseline to facilitate the statistical determination of when climate conditions are extreme, having sufficient knowledge of ecological systems so that extreme ecological responses can be identified, and finally, being able to attribute a climate extreme as the driver of an extreme ecological response, defined as an extreme climatic event (ECE).3. The papers in this issue represent a cross-section of the emerging field of climate extremes research, including an examination of the palaeo-ecological record to assess patterns and drivers of extreme ecological responses in the late Quaternary, experiments in grasslands assessing a range of ecological responses and the role of ecotypic variation in determining responses to climate extremes, and the quantification of the ecological consequences of a recent ECE in the desert Southwest of the USA.4. Synthesis. The papers in this Special Feature suggest that although the occurrence of ECEs may be common in palaeo-ecological and observational studies, studies in which climate extremes have been experimentally imposed often do not result in ecological responses outside the bounds of normal variability of a system. Thus, ECEs occur much less frequently than their potential drivers and even less frequently than observational studies suggest. Future research is needed to identify the types and time-scales of climate extremes that result in ECEs, the potential for interactions among different types of climate changes and extremes, and the role of genetic, species and trait diversity in determining ecological responses and their evolutionary consequences. These research priorities require the development of alternative research approaches to impose realistic climate extremes on a broad range of organisms and ecosystems.]]>
DOI:10.1890/08-1815.1URLPMID:20120798 [本文引用: 1]
In contrast to pulses in resource availability following disturbance events, many of the most pressing global changes, such as elevated atmospheric carbon dioxide concentrations and nitrogen deposition, lead to chronic and often cumulative alterations in available resources. Therefore, predicting ecological responses to these chronic resource alterations will require the modification of existing disturbance-based frameworks. Here, we present a conceptual framework for assessing the nature and pace of ecological change under chronic resource alterations. The
DOI:10.1111/j.1365-2486.2012.02797.xURLPMID:23504720 [本文引用: 1]
To realistically simulate climate feedbacks from the land surface to the atmosphere, models must replicate the responses of plants to environmental changes. Several processes, operating at various scales, cause the responses of photosynthesis and plant respiration to temperature and CO2 to change over time of exposure to new or changing environmental conditions. Here, we review the latest empirical evidence that short-term responses of plant carbon exchange rates to temperature and CO2 are modified by plant photosynthetic and respiratory acclimation as well as biogeochemical feedbacks. We assess the frequency with which these responses have been incorporated into vegetation models, and highlight recently designed algorithms that can facilitate their incorporation. Few models currently include representations of the long-term plant responses that have been recorded by empirical studies, likely because these responses are still poorly understood at scales relevant for models. Studies show that, at a regional scale, simulated carbon flux between the atmosphere and vegetation can dramatically differ between versions of models that do and do not include acclimation. However, the realism of these results is difficult to evaluate, as algorithm development is still in an early stage, and a limited number of data are available. We provide a series of recommendations that suggest how a combination of empirical and modeling studies can produce mechanistic algorithms that will realistically simulate longer term responses within global-scale models.
DOI:10.1111/gcb.13735URLPMID:28560841 [本文引用: 1]
While temperature responses of photosynthesis and plant respiration are known to acclimate over time in many species, few studies have been designed to directly compare process-level differences in acclimation capacity among plant types. We assessed short-term (7 day) temperature acclimation of the maximum rate of Rubisco carboxylation (Vcmax ), the maximum rate of electron transport (Jmax ), the maximum rate of phosphoenolpyruvate carboxylase carboxylation (Vpmax ), and foliar dark respiration (Rd ) in 22 plant species that varied in lifespan (annual and perennial), photosynthetic pathway (C3 and C4 ), and climate of origin (tropical and nontropical) grown under fertilized, well-watered conditions. In general, acclimation to warmer temperatures increased the rate of each process. The relative increase in different photosynthetic processes varied by plant type, with C3 species tending to preferentially accelerate CO2 -limited photosynthetic processes and respiration and C4 species tending to preferentially accelerate light-limited photosynthetic processes under warmer conditions. Rd acclimation to warmer temperatures caused a reduction in temperature sensitivity that resulted in slower rates at high leaf temperatures. Rd acclimation was similar across plant types. These results suggest that temperature acclimation of the biochemical processes that underlie plant carbon exchange is common across different plant types, but that acclimation to warmer temperatures tends to have a relatively greater positive effect on the processes most limiting to carbon assimilation, which differ by plant type. The acclimation responses observed here suggest that warmer conditions should lead to increased rates of carbon assimilation when water and nutrients are not limiting.
DOI:10.1098/rstb.2007.2184URL [本文引用: 1]
DOI:10.1038/s41559-019-0958-3URLPMID:31427733 [本文引用: 1]
Direct quantification of terrestrial biosphere responses to global change is crucial for projections of future climate change in Earth system models. Here, we synthesized ecosystem carbon-cycling data from 1,119 experiments performed over the past four decades concerning changes in temperature, precipitation, CO2 and nitrogen across major terrestrial vegetation types of the world. Most experiments manipulated single rather than multiple global change drivers in temperate ecosystems of the USA, Europe and China. The magnitudes of warming and elevated CO2 treatments were consistent with the ranges of future projections, whereas those of precipitation changes and nitrogen inputs often exceeded the projected ranges. Increases in global change drivers consistently accelerated, but decreased precipitation slowed down carbon-cycle processes. Nonlinear (including synergistic and antagonistic) effects among global change drivers were rare. Belowground carbon allocation responded negatively to increased precipitation and nitrogen addition and positively to decreased precipitation and elevated CO2. The sensitivities of carbon variables to multiple global change drivers depended on the background climate and ecosystem condition, suggesting that Earth system models should be evaluated using site-specific conditions for best uses of this large dataset. Together, this synthesis underscores an urgent need to explore the interactions among multiple global change drivers in underrepresented regions such as semi-arid ecosystems, forests in the tropics and subtropics, and Arctic tundra when forecasting future terrestrial carbon-climate feedback.
DOI:10.1038/s41586-018-0005-6URLPMID:29618821 [本文引用: 1]
Globally accelerating trends in societal development and human environmental impacts since the mid-twentieth century (1-7) are known as the Great Acceleration and have been discussed as a key indicator of the onset of the Anthropocene epoch (6) . While reports on ecological responses (for example, changes in species range or local extinctions) to the Great Acceleration are multiplying (8, 9) , it is unknown whether such biotic responses are undergoing a similar acceleration over time. This knowledge gap stems from the limited availability of time series data on biodiversity changes across large temporal and geographical extents. Here we use a dataset of repeated plant surveys from 302 mountain summits across Europe, spanning 145 years of observation, to assess the temporal trajectory of mountain biodiversity changes as a globally coherent imprint of the Anthropocene. We find a continent-wide acceleration in the rate of increase in plant species richness, with five times as much species enrichment between 2007 and 2016 as fifty years ago, between 1957 and 1966. This acceleration is strikingly synchronized with accelerated global warming and is not linked to alternative global change drivers. The accelerating increases in species richness on mountain summits across this broad spatial extent demonstrate that acceleration in climate-induced biotic change is occurring even in remote places on Earth, with potentially far-ranging consequences not only for biodiversity, but also for ecosystem functioning and services.
DOI:10.1126/science.1171542URLPMID:19443769 [本文引用: 1]
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DOI:10.1111/jzo.2006.268.issue-4URL [本文引用: 1]
DOI:10.1097/00010694-192907000-00005URL [本文引用: 1]
DOI:10.1111/pce.12417URLPMID:25065257 [本文引用: 1]
The number and intensity of heat waves has increased, and this trend is likely to continue throughout the 21st century. Often, heat waves are accompanied by drought conditions. It is projected that the global land area experiencing heat waves will double by 2020, and quadruple by 2040. Extreme heat events can impact a wide variety of tree functions. At the leaf level, photosynthesis is reduced, photooxidative stress increases, leaves abscise and the growth rate of remaining leaves decreases. In some species, stomatal conductance increases at high temperatures, which may be a mechanism for leaf cooling. At the whole plant level, heat stress can decrease growth and shift biomass allocation. When drought stress accompanies heat waves, the negative effects of heat stress are exacerbated and can lead to tree mortality. However, some species exhibit remarkable tolerance to thermal stress. Responses include changes that minimize stress on photosynthesis and reductions in dark respiration. Although there have been few studies to date, there is evidence of within-species genetic variation in thermal tolerance, which could be important to exploit in production forestry systems. Understanding the mechanisms of differing tree responses to extreme temperature events may be critically important for understanding how tree species will be affected by climate change.
DOI:10.1038/nature18608URLPMID:27362222 [本文引用: 1]
Differences in phenological responses to climate change among species can desynchronise ecological interactions and thereby threaten ecosystem function. To assess these threats, we must quantify the relative impact of climate change on species at different trophic levels. Here, we apply a Climate Sensitivity Profile approach to 10,003 terrestrial and aquatic phenological data sets, spatially matched to temperature and precipitation data, to quantify variation in climate sensitivity. The direction, magnitude and timing of climate sensitivity varied markedly among organisms within taxonomic and trophic groups. Despite this variability, we detected systematic variation in the direction and magnitude of phenological climate sensitivity. Secondary consumers showed consistently lower climate sensitivity than other groups. We used mid-century climate change projections to estimate that the timing of phenological events could change more for primary consumers than for species in other trophic levels (6.2 versus 2.5-2.9 days earlier on average), with substantial taxonomic variation (1.1-14.8 days earlier on average).
DOI:10.5194/bg-6-2099-2009URL [本文引用: 1]
[本文引用: 1]
DOI:10.5194/bg-10-1717-2013URL [本文引用: 1]
Stocks of soil organic carbon represent a large component of the carbon cycle that may participate in climate change feedbacks, particularly on decadal and centennial timescales. For Earth system models (ESMs), the ability to accurately represent the global distribution of existing soil carbon stocks is a prerequisite for accurately predicting future carbon-climate feedbacks. We compared soil carbon simulations from 11 model centers to empirical data from the Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). Model estimates of global soil carbon stocks ranged from 510 to 3040 Pg C, compared to an estimate of 1260 Pg C (with a 95% confidence interval of 890-1660 Pg C) from the HWSD. Model simulations for the high northern latitudes fell between 60 and 820 Pg C, compared to 500 Pg C (with a 95% confidence interval of 380-620 Pg C) for the NCSCD and 290 PgC for the HWSD. Global soil carbon varied 5.9 fold across models in response to a 2.6-fold variation in global net primary productivity (NPP) and a 3.6-fold variation in global soil carbon turnover times. Model-data agreement was moderate at the biome level (R-2 values ranged from 0.38 to 0.97 with a mean of 0.75); however, the spatial distribution of soil carbon simulated by the ESMs at the 1 degrees scale was not well correlated with the HWSD (Pearson correlation coefficients less than 0.4 and root mean square errors from 9.4 to 20.8 kg C m(-2)). In northern latitudes where the two data sets overlapped, agreement between the HWSD and the NCSCD was poor (Pearson correlation coefficient 0.33), indicating uncertainty in empirical estimates of soil carbon. We found that a reduced complexity model dependent on NPP and soil temperature explained much of the 1 degrees spatial variation in soil carbon within most ESMs (R-2 values between 0.62 and 0.93 for 9 of 11 model centers). However, the same reduced complexity model only explained 10% of the spatial variation in HWSD soil carbon when driven by observations of NPP and temperature, implying that other drivers or processes may be more important in explaining observed soil carbon distributions. The reduced complexity model also showed that differences in simulated soil carbon across ESMs were driven by differences in simulated NPP and the parameterization of soil heterotrophic respiration (inter-model R-2 = 0.93), not by structural differences between the models. Overall, our results suggest that despite fair global-scale agreement with observational data and moderate agreement at the biome scale, most ESMs cannot reproduce grid-scale variation in soil carbon and may be missing key processes. Future work should focus on improving the simulation of driving variables for soil carbon stocks and modifying model structures to include additional processes.
[本文引用: 1]
DOI:10.1111/j.1466-8238.2011.00717.xURL [本文引用: 1]
Aim Despite their importance for predicting fluxes to and from terrestrial ecosystems, dynamic global vegetation models have insufficient realism because of their use of plant functional types (PFTs) with constant attributes. Based on recent advances in community ecology, we explore the merits of a traits-based vegetation model to deal with current shortcomings. Location Global. Methods A research review of current concepts and information, providing a new perspective, supported by quantitative analysis of a global traits database. Results Continuous and process-based traitenvironment relations are central to a traits-based approach and allow us to directly calculate fluxes based on functional characteristics. By quantifying community assembly concepts, it is possible to predict trait values from environmental drivers, although these relations are still imperfect. Through the quantification of these relations, effects of adaptation and species replacement upon environmental changes are implicitly accounted for. Such functional links also allow direct calculation of fluxes, including those related to feedbacks through the nitrogen and water cycle. Finally, a traits-based model allows the prediction of new trait combinations and no-analogue ecosystem functions projected to arise in the near future, which is not feasible in current vegetation models. A separate calculation of ecosystem fluxes and PFT occurrences in traits-based models allows for flexible vegetation classifications. Main conclusions Given the advantages described above, we argue that traits-based modelling deserves consideration (although it will not be easy) if one is to aim for better climate projections.
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DOI:10.1126/science.1165000URLPMID:19164752 [本文引用: 1]
Persistent changes in tree mortality rates can alter forest structure, composition, and ecosystem services such as carbon sequestration. Our analyses of longitudinal data from unmanaged old forests in the western United States showed that background (noncatastrophic) mortality rates have increased rapidly in recent decades, with doubling periods ranging from 17 to 29 years among regions. Increases were also pervasive across elevations, tree sizes, dominant genera, and past fire histories. Forest density and basal area declined slightly, which suggests that increasing mortality was not caused by endogenous increases in competition. Because mortality increased in small trees, the overall increase in mortality rates cannot be attributed solely to aging of large trees. Regional warming and consequent increases in water deficits are likely contributors to the increases in tree mortality rates.
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URLPMID:25611824 [本文引用: 1]
DOI:10.1073/pnas.1717342115URLPMID:29279381 [本文引用: 1]
One hundred years ago, Andrew D. Hopkins estimated the progressive delay in tree leaf-out with increasing latitude, longitude, and elevation, referred to as
DOI:10.1073/pnas.0503198103URLPMID:16428292 [本文引用: 2]
Recent observations of changes in some tundra ecosystems appear to be responses to a warming climate. Several experimental studies have shown that tundra plants and ecosystems can respond strongly to environmental change, including warming; however, most studies were limited to a single location and were of short duration and based on a variety of experimental designs. In addition, comparisons among studies are difficult because a variety of techniques have been used to achieve experimental warming and different measurements have been used to assess responses. We used metaanalysis on plant community measurements from standardized warming experiments at 11 locations across the tundra biome involved in the International Tundra Experiment. The passive warming treatment increased plant-level air temperature by 1-3 degrees C, which is in the range of predicted and observed warming for tundra regions. Responses were rapid and detected in whole plant communities after only two growing seasons. Overall, warming increased height and cover of deciduous shrubs and graminoids, decreased cover of mosses and lichens, and decreased species diversity and evenness. These results predict that warming will cause a decline in biodiversity across a wide variety of tundra, at least in the short term. They also provide rigorous experimental evidence that recently observed increases in shrub cover in many tundra regions are in response to climate warming. These changes have important implications for processes and interactions within tundra ecosystems and between tundra and the atmosphere.
URLPMID:31819236 [本文引用: 1]
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DOI:10.1038/416389aURLPMID:11919621 [本文引用: 1]
There is now ample evidence of the ecological impacts of recent climate change, from polar terrestrial to tropical marine environments. The responses of both flora and fauna span an array of ecosystems and organizational hierarchies, from the species to the community levels. Despite continued uncertainty as to community and ecosystem trajectories under global change, our review exposes a coherent pattern of ecological change across systems. Although we are only at an early stage in the projected trends of global warming, ecological responses to recent climate change are already clearly visible.
DOI:10.1890/08-2026.1URLPMID:19886480 [本文引用: 2]
A mechanistic understanding of the carbon (C) cycle-climate change feedback is essential for projecting future states of climate and ecosystems. Here we report a novel field mechanism and evidence supporting the hypothesis that nocturnal warming in a temperate steppe ecosystem in northern China can result in a minor C sink instead of a C source as models have predicted. Nocturnal warming increased leaf respiration of two dominant grass species by 36.3%, enhanced consumption of carbohydrates in the leaves (72.2% and 60.5% for sugar and starch, respectively), and consequently stimulated plant photosynthesis by 19.8% in the subsequent days. Our experimental findings confirm previous observations of nocturnal warming stimulating plant photosynthesis through increased draw-down of leaf carbohydrates at night. The enhancement of plant photosynthesis overcompensated the increased C loss via plant respiration under nocturnal warming and shifted the steppe ecosystem from a minor C source (1.87 g C x m(-2) x yr(-1)) to a C sink (21.72 g C x m(-2) x yr(-1)) across the three growing seasons from 2006 to 2008. Given greater increases in daily minimum than maximum temperature in many regions, plant photosynthetic overcompensation may partially serve as a negative feedback mechanism for terrestrial biosphere to climate warming.
DOI:10.1890/14-0292.1URLPMID:26236896 [本文引用: 1]
Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when predicting future decomposition rates and carbon storage in peatlands.
DOI:10.1093/treephys/tpq015URLPMID:20368338 [本文引用: 1]
The response of tree growth to a change in temperature may differ in predictable ways. Trees with conservative growth strategies may have little ability to respond to a changing climate. In addition, high latitude and altitude tree growth may be temperature-limited and thus benefit from some degree of warming, as opposed to warm-adapted species. Using data from 63 studies, we examined whether trees from different functional groups and thermal niches differed in their growth response to a change in growth temperature. We also investigated whether responses predicted for a change in growth temperature (both reduced and elevated) were similar for increased temperatures by repeating the analysis on the subset of raised temperature data to confirm the validity of our results for use in a climate-warming scenario. Using both the temperature-change response and the warming response, we found that elevated temperatures enhanced growth (measured as shoot height, stem diameter and biomass) in deciduous species more than in evergreen trees. Tropical species were indeed more susceptible to warming-induced growth declines than temperate or boreal trees in both analyses. More carbon may be available to allocate to growth at high temperatures because respiration acclimated more strongly than photosynthesis, increasing carbon assimilation but moderating carbon losses. Trees that developed at elevated temperatures did not simply accelerate growth but followed different developmental trajectories than unwarmed trees, allocating more biomass to leaves and less to roots and growing taller for a given stem diameter. While there were insufficient data to analyze trends for particular species, we generated equations to describe general trends in tree growth to temperature changes and to warming for use at large spatial scales or where data are lacking. We discuss the implications of these results in the context of a changing climate and highlight the areas of greatest uncertainty regarding temperature and tree growth where future research is needed.
URLPMID:23812760 [本文引用: 2]
DOI:10.1890/0012-9658(2000)081[3464:ROBAFP]2.0.CO;2URL [本文引用: 1]
DOI:10.1111/ecog.00521URL [本文引用: 1]
As the earth is getting warmer, many animals and plants have shifted their timing of breeding towards earlier dates. However, there is substantial variation between populations in phenological shifts that typically goes unexplained. Identification of the different location and species characteristics that drive such variable responses to global warming is crucial if we are to make predictions for how projected climate change scenarios will play out on local and global scales. Here we conducted a phylogenetically controlled meta-analysis of breeding phenology across frogs, toads and salamanders to examine the extent of variation in amphibian breeding phenology in response to global climate change. We show that there is strong geographic variation in response to global climate change, with species at higher latitudes exhibiting a more pronounced shift to earlier breeding than those at lower latitudes. Our analyses suggest that this latitude effect is a result of both the increased temperature (but not precipitation) at higher latitudes as well as a greater responsiveness by northern populations of amphibians to this change in temperature. We suggest that these effects should reinforce any direct effect of increasing warming at higher latitudes on breeding phenology. In contrast, we found very little contribution from other location factors or species traits. There was no evidence for a phylogenetic signal on advancing breeding phenology or responsiveness to temperature, suggesting that the amphibians that have been studied to date respond similarly to global warming.
DOI:10.5194/gmd-8-1789-2015URL [本文引用: 1]
DOI:10.1038/ncomms13723URLPMID:27958276 [本文引用: 1]
Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. We show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH4 emissions. However, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20-30 cm of peat from experimental plots have higher CH4 production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH4 and CO2 are produced primarily from decomposition of surface-derived modern photosynthate, not catotelm C. There are no differences in microbial abundances, dissolved organic matter concentrations or degradative enzyme activities among treatments. These results suggest that although surface peat will respond to increasing temperature, the large reservoir of catotelm C is stable under current anoxic conditions.
DOI:10.1126/science.1116913URLPMID:16284173 [本文引用: 1]
Rapid global warming of 5 degrees to 10 degrees C during the Paleocene-Eocene Thermal Maximum (PETM) coincided with major turnover in vertebrate faunas, but previous studies have found little floral change. Plant fossils discovered in Wyoming, United States, show that PETM floras were a mixture of native and migrant lineages and that plant range shifts were large and rapid (occurring within 10,000 years). Floral composition and leaf shape and size suggest that climate warmed by approximately 5 degrees C during the PETM and that precipitation was low early in the event and increased later. Floral response to warming and/or increased atmospheric CO2 during the PETM was comparable in rate and magnitude to that seen in postglacial floras and to the predicted effects of anthropogenic carbon release and climate change on future vegetation.
URLPMID:22622576 [本文引用: 1]
DOI:10.1038/nature02403URLPMID:15103368 [本文引用: 1]
Bringing together leaf trait data spanning 2,548 species and 175 sites we describe, for the first time at global scale, a universal spectrum of leaf economics consisting of key chemical, structural and physiological properties. The spectrum runs from quick to slow return on investments of nutrients and dry mass in leaves, and operates largely independently of growth form, plant functional type or biome. Categories along the spectrum would, in general, describe leaf economic variation at the global scale better than plant functional types, because functional types overlap substantially in their leaf traits. Overall, modulation of leaf traits and trait relationships by climate is surprisingly modest, although some striking and significant patterns can be seen. Reliable quantification of the leaf economics spectrum and its interaction with climate will prove valuable for modelling nutrient fluxes and vegetation boundaries under changing land-use and climate.
DOI:10.1038/NCLIMATE1486URL [本文引用: 1]
Plant growth often responds rapidly to experimentally simulated climate change(1,2). Feedbacks can modulate the initial responses(3), but these feedbacks are difficult to detect when they operate on long timescales(4). We transplanted intact plant-soil mesocosms down an elevation gradient to expose them to a warmer climate and used collectors and interceptors to simulate changes in precipitation. Here, we show that warming initially increased aboveground net primary productivity in four grassland ecosystems, but the response diminished progressively over nine years. Warming altered the plant community, causing encroachment by species typical of warmer environments and loss of species from the native environment-trends associated with the declining response of plant productivity. Warming stimulated soil nitrogen turnover, which dampened but did not reverse the temporal decline in the productivity, response. Warming also enhanced N losses, which may have weakened the expected biogeochemical feedback where warming stimulates N mineralization and plant growth(1,5,6). Our results, describing the responses of four ecosystems to nearly a decade of simulated climate change, indicate that short-term experiments are insufficient to capture the temporal variability and trend of ecosystem responses to environmental change and their modulation through biogeochemical and ecological feedbacks.
DOI:10.1038/NGEO2093URL [本文引用: 6]
Feedbacks between the terrestrial carbon cycle and climate change could affect many ecosystem functions and services, such as food production, carbon sequestration and climate regulation. The rate of climate warming varies on diurnal and seasonal timescales. A synthesis of global air temperature data reveals a greater rate of warming in winter than in summer in northern mid and high latitudes, and the inverse pattern in some tropical regions. The data also reveal a decline in the diurnal temperature range over 51% of the global land area and an increase over only 13%, because night-time temperatures in most locations have risen faster than daytime temperatures. Analyses of satellite data, model simulations and in situ observations suggest that the impact of seasonal warming varies between regions. For example, spring warming has largely stimulated ecosystem productivity at latitudes between 30 degrees and 90 degrees N, but suppressed productivity in other regions. Contrasting impacts of day- and night-time warming on plant carbon gain and loss are apparent in many regions. We argue that ascertaining the effects of non-uniform climate warming on terrestrial ecosystems is a key challenge in carbon cycle research.
DOI:10.1111/gcb.12172URLPMID:23505019 [本文引用: 3]
Biogeochemical models have been developed to account for more and more processes, making their complex structures difficult to be understood and evaluated. Here, we introduce a framework to decompose a complex land model into traceable components based on mutually independent properties of modeled biogeochemical processes. The framework traces modeled ecosystem carbon storage capacity (Xss ) to (i) a product of net primary productivity (NPP) and ecosystem residence time (tauE ). The latter tauE can be further traced to (ii) baseline carbon residence times (tau'E ), which are usually preset in a model according to vegetation characteristics and soil types, (iii) environmental scalars (xi), including temperature and water scalars, and (iv) environmental forcings. We applied the framework to the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model to help understand differences in modeled carbon processes among biomes and as influenced by nitrogen processes. With the climate forcings of 1990, modeled evergreen broadleaf forest had the highest NPP among the nine biomes and moderate residence times, leading to a relatively high carbon storage capacity (31.5 kg cm(-2) ). Deciduous needle leaf forest had the longest residence time (163.3 years) and low NPP, leading to moderate carbon storage (18.3 kg cm(-2) ). The longest tauE in deciduous needle leaf forest was ascribed to its longest tau'E (43.6 years) and small xi (0.14 on litter/soil carbon decay rates). Incorporation of nitrogen processes into the CABLE model decreased Xss in all biomes via reduced NPP (e.g., -12.1% in shrub land) or decreased tauE or both. The decreases in tauE resulted from nitrogen-induced changes in tau'E (e.g., -26.7% in C3 grassland) through carbon allocation among plant pools and transfers from plant to litter and soil pools. Our framework can be used to facilitate data model comparisons and model intercomparisons via tracking a few traceable components for all terrestrial carbon cycle models. Nevertheless, more research is needed to develop tools to decompose NPP and transient dynamics of the modeled carbon cycle into traceable components for structural analysis of land models.
[本文引用: 4]
DOI:10.1111/gcb.2009.15.issue-6URL [本文引用: 1]
DOI:10.1111/j.1469-8137.2008.02488.xURLPMID:19086179 [本文引用: 1]
Better understanding of the responses of terrestrial plant species under global nitrogen (N) enrichment is critical for projection of changes in structure, functioning, and service of terrestrial ecosystems. Here, a meta-analysis of data from 304 studies was carried out to reveal the general response patterns of terrestrial plant species to the addition of N. Across 456 terrestrial plant species included in the analysis, biomass and N concentration were increased by 53.6 and 28.5%, respectively, under N enrichment. However, the N responses were dependent upon plant functional types, with significantly greater biomass increases in herbaceous than in woody species. Stimulation of plant biomass by the addition of N was enhanced when other resources were improved. In addition, the N responses of terrestrial plants decreased with increasing latitude and increased with annual precipitation. Dependence of the N responses of terrestrial plants on biological realms, functional types, tissues, other resources, and climatic factors revealed in this study can help to explain changes in species composition, diversity, community structure and ecosystem functioning under global N enrichment. These findings are critical in improving model simulation and projection of terrestrial carbon sequestration and its feedbacks to global climate change, especially when progressive N limitation is taken into consideration.
DOI:10.1093/aob/mct079URLPMID:23585496 [本文引用: 1]
BACKGROUND AND AIMS: Phenology is one of most sensitive traits of plants in response to regional climate warming. Better understanding of the interactive effects between warming and other environmental change factors, such as increasing atmosphere nitrogen (N) deposition, is critical for projection of future plant phenology. METHODS: A 4-year field experiment manipulating temperature and N has been conducted in a temperate steppe in northern China. Phenology, including flowering and fruiting date as well as reproductive duration, of eight plant species was monitored and calculated from 2006 to 2009. KEY RESULTS: Across all the species and years, warming significantly advanced flowering and fruiting time by 0.64 and 0.72 d per season, respectively, which were mainly driven by the earliest species (Potentilla acaulis). Although N addition showed no impact on phenological times across the eight species, it significantly delayed flowering time of Heteropappus altaicus and fruiting time of Agropyron cristatum. The responses of flowering and fruiting times to warming or N addition are coupled, leading to no response of reproductive duration to warming or N addition for most species. Warming shortened reproductive duration of Potentilla bifurca but extended that of Allium bidentatum, whereas N addition shortened that of A. bidentatum. No interactive effect between warming and N addition was found on any phenological event. Such additive effects could be ascribed to the species-specific responses of plant phenology to warming and N addition. CONCLUSIONS: The results suggest that the warming response of plant phenology is larger in earlier than later flowering species in temperate grassland systems. The effects of warming and N addition on plant phenology are independent of each other. These findings can help to better understand and predict the response of plant phenology to climate warming concurrent with other global change driving factors.
DOI:10.1016/j.soilbio.2018.05.009URL [本文引用: 2]
DOI:10.1038/nclimate1836URL [本文引用: 1]
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DOI:10.1038/nclimate2940URL [本文引用: 1]
DOI:10.1007/s11120-013-9874-6URLPMID:23801171 [本文引用: 1]
Most plants show considerable capacity to adjust their photosynthetic characteristics to their growth temperatures (temperature acclimation). The most typical case is a shift in the optimum temperature for photosynthesis, which can maximize the photosynthetic rate at the growth temperature. These plastic adjustments can allow plants to photosynthesize more efficiently at their new growth temperatures. In this review article, we summarize the basic differences in photosynthetic reactions in C3, C4, and CAM plants. We review the current understanding of the temperature responses of C3, C4, and CAM photosynthesis, and then discuss the underlying physiological and biochemical mechanisms for temperature acclimation of photosynthesis in each photosynthetic type. Finally, we use the published data to evaluate the extent of photosynthetic temperature acclimation in higher plants, and analyze which plant groups (i.e., photosynthetic types and functional types) have a greater inherent ability for photosynthetic acclimation to temperature than others, since there have been reported interspecific variations in this ability. We found that the inherent ability for temperature acclimation of photosynthesis was different: (1) among C3, C4, and CAM species; and (2) among functional types within C3 plants. C3 plants generally had a greater ability for temperature acclimation of photosynthesis across a broad temperature range, CAM plants acclimated day and night photosynthetic process differentially to temperature, and C4 plants was adapted to warm environments. Moreover, within C3 species, evergreen woody plants and perennial herbaceous plants showed greater temperature homeostasis of photosynthesis (i.e., the photosynthetic rate at high-growth temperature divided by that at low-growth temperature was close to 1.0) than deciduous woody plants and annual herbaceous plants, indicating that photosynthetic acclimation would be particularly important in perennial, long-lived species that would experience a rise in growing season temperatures over their lifespan. Interestingly, across growth temperatures, the extent of temperature homeostasis of photosynthesis was maintained irrespective of the extent of the change in the optimum temperature for photosynthesis (T opt), indicating that some plants achieve greater photosynthesis at the growth temperature by shifting T opt, whereas others can also achieve greater photosynthesis at the growth temperature by changing the shape of the photosynthesis-temperature curve without shifting T opt. It is considered that these differences in the inherent stability of temperature acclimation of photosynthesis would be reflected by differences in the limiting steps of photosynthetic rate.
DOI:10.1104/pp.109.146514URLPMID:19837817 [本文引用: 1]
The activation of Rubisco in vivo requires the presence of the regulatory protein Rubisco activase. To elucidate its role in maintaining CO(2) assimilation rate at high temperature, we examined the temperature response of CO(2) assimilation rate at 380 microL L(-1) CO(2) concentration (A(380)) and Rubisco activation state in wild-type and transgenic tobacco (Nicotiana tabacum) with reduced Rubisco activase content grown at either 20 degrees C or 30 degrees C. Analyses of gas exchange and chlorophyll fluorescence showed that in the wild type, A(380) was limited by ribulose 1,5-bisphosphate regeneration at lower temperatures, whereas at higher temperatures, A(380) was limited by ribulose 1,5-bisphosphate carboxylation irrespective of growth temperatures. Growth temperature induced modest differences in Rubisco activation state that declined with measuring temperature, from mean values of 76% at 15 degrees C to 63% at 40 degrees C in wild-type plants. At measuring temperatures of 25 degrees C and below, an 80% reduction in Rubisco activase content was required before Rubisco activation state was decreased. Above 35 degrees C, Rubisco activation state decreased slightly with more modest decreases in Rubisco activase content, but the extent of the reductions in Rubisco activation state were small, such that a 55% reduction in Rubisco activase content did not alter the temperature sensitivity of Rubisco activation and had no effect on in vivo catalytic turnover rates of Rubisco. There was a strong correlation between Rubisco activase content and Rubisco activation state once Rubisco activase content was less that 20% of wild type at all measuring temperatures. We conclude that reduction in Rubisco activase content does not lead to an increase in the temperature sensitivity of Rubisco activation state in tobacco.
[本文引用: 1]
DOI:10.1111/gcb.13830URLPMID:28727222 [本文引用: 1]
DOI:10.1038/nclimate2549URL [本文引用: 1]
DOI:10.1093/jpe/rtn002URL [本文引用: 1]
Aims We aim to construct a comprehensive global database of litter decomposition rate (k value) estimated by surface floor litterbags, and investigate the direct and indirect effects of impact factors such as geographic factors (latitude and altitude), climatic factors (mean annual tempePlrature, MAT; mean annual precipitation, MAP) and litter quality factors (the contents of N, P, K, Ca, Mg and C:N ratio, lignin:N ratio) on litter decomposition.Methods We compiled a large data set of litter decomposition rates (k values) from 110 research sites and conducted simple, multiple regression and path analyses to explore the relationship between the k values and impact factors at the global scale.Important findings The k values tended to decrease with latitude (LAT) and lignin content (LIGN) of litter but increased with temperature, precipitation and nutrient concentrations at the large spatial scale. Single factor such as climate, litter quality and geographic variable could not explain litter decomposition rates well. However, the combination of total nutrient (TN) elements and C:N accounted for 70.2% of the variation in the litter decomposition rates. The combination of LAT, MAT, C:N and TN accounted for 87.54% of the variation in the litter decomposition rates. These results indicate that litter quality is the most important direct regulator of litter decomposition at the global scale. This data synthesis revealed significant relationships between litter decomposition rates and the combination of climatic factor (MAT) and litter quality (C:N, TN). The global-scale empirical relationships developed here are useful for a better understanding and modeling of the effects of litter quality and climatic factors on litter decomposition rates.]]>
[本文引用: 1]
DOI:10.1111/gcb.13723URLPMID:28417528 [本文引用: 1]
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The Millennial model: in search of measurable pools and transformations for modeling soil carbon in the new century
1
2018
... 土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(
On underestimation of global vulnerability to tree mortality and forest die-off from hotter drought in the Anthropocene
1
2015
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
A global overview of drought and heat- induced tree mortality reveals emerging climate change risks for forests
1
2010
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Temperature sensitivities of extracellular enzyme Vmax and Km across thermal environments
1
2018
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Plant nitrogen concentration, use efficiency, and contents in a tallgrass prairie ecosystem under experimental warming
1
2005
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink
1
2015
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
The roles of hydraulic and carbon stress in a widespread climate-induced forest die-off
1
2012
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
On the developmental dependence of leaf respiration: responses to short- and long-term changes in growth temperature
1
2006
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Terrestrial biogeochemical feedbacks in the climate system
2
2010
... 生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Using temperature-dependent changes in leaf scaling relationships to quantitatively account for thermal acclimation of respiration in a coupled global climate-vegetation model
1
2008
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Response of plant respiration to changes in temperature: mechanisms and consequences of variations in Q10 values and acclimation//Lambers H, Ribas-Carbo M. Plant Respiration
1
2005
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Thermal acclimation and the dynamic response of plant respiration to temperature
3
2003
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
... ), 并产生温度敏感性下降的现象(
... )与呼吸底物和腺苷酸的限制(
A metaanalysis of experimental warming effects on terrestrial nitrogen pools and dynamics
3
2013
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Photosynthetic response and adaptation to temperature in higher plants
2
1980
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Changes in plant community composition lag behind climate warming in lowland forests
1
2011
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Globally rising soil heterotrophic respiration over recent decades
1
2018
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Climate fails to predict wood decomposition at regional scales
1
2014
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Widespread seasonal compensation effects of spring warming on northern plant productivity
1
2018
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
The sensitivity of photosynthesis to O2 and CO2 concentration identifies strong Rubisco control above the thermal optimum
1
2017
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Dynamic responses of terrestrial ecosystem carbon cycling to global climate change
1
1998
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Poleward expansion of mangroves is a threshold response to decreased frequency of extreme cold events
1
2014
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Soil burial contributes to deep soil organic carbon storage
1
2014
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
Global convergence in the vulnerability of forests to drought
1
2012
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Europe-wide reduction in primary productivity caused by the heat and drought in 2003
1
2005
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Tropical rain forest tree growth and atmospheric carbon dynamics linked to interannual temperature variation during 1984-2000
1
2003
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Ecological forecasts: an emerging imperative
1
2001
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Environmental effects on peppermint (Mentha piperita L.). II. Effects of temperature on photosynthesis, photorespiration and dark respiration in peppermint with reference to oil composition
1
1980
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Diverse responses of phenology to global changes in a grassland ecosystem
1
2006
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
A global synthesis of animal phenological responses to climate change
1
2018
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Is NPP proportional to GPP? Waring’s hypothesis 20 years on
1
2019
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Mycorrhizal mediation of plant and ecosystem responses to soil warming//Mohan JE. Ecosystem Consequences of Soil Warming
1
2019
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model
1
2000
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
Rubisco activase constrains the photosynthetic potential of leaves at high temperature and CO2
1
2000
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Acclimation of light and dark respiration to experimental and seasonal warming are mediated by changes in leaf nitrogen in Eucalyptus globulus
1
2017
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Quantifying global soil carbon losses in response to warming
2
2016
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
... 的挑战, 该研究整合分析了143个实验数据, 发现
Robust leaf trait relationships across species under global environmental changes
1
2020
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Iterative near-term ecological forecasting: needs, opportunities, and challenges
1
2018
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Climate change alters stoichiometry of phosphorus and nitrogen in a semiarid grassland
2
2012
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
... ).目前, 更多的研究主要关注增温对植物和微生物体内碳氮磷计量关系的影响(
Decadal soil carbon accumulation across Tibetan permafrost regions
1
2017
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
Understanding the rapid summer warming and changes in temperature extremes since the mid-1990s over Western Europe
1
2017
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Antarctic climate cooling and terrestrial ecosystem response
1
2002
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Source and sink carbon dynamics and carbon allocation in the Amazon basin
1
2015
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Tropical forest leaves may darken in response to climate change
1
2018
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Climate warming and tree carbon use efficiency in a whole-tree13CO2 tracer study
1
2019
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Impacts of global environmental change drivers on non-structural carbohydrates in terrestrial plants
2
2020
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Plant carbon metabolism and climate change: elevated CO2 and temperature impacts on photosynthesis, photorespiration and respiration
2
2019
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
... ;
Maximum and minimum temperature trends for the globe
1
1997
... IPCC第五次评估报告指出, 全球气温的升高在昼夜间和季节间均呈现出明显的不对称性, 即平均夜间增温幅度大于白天增温幅度(
Climatic change and the broad-scale distribution of terrestrial ecosystem complexes
1
1985
... 关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪.古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(
生态系统对全球变暖的响应
1
2018
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
生态系统对全球变暖的响应
1
2018
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
Air temperature and winter mortality: implications for the persistence of the invasive mussel, Perna viridis in the intertidal zone of the south-eastern United States
1
2011
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Anthropogenic contribution to global occurrence of heavy-precipitation and high- temperature extremes
1
2015
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Rapid changes in flowering time in British plants
1
2002
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Effects of soil freezing disturbance on soil solution nitrogen, phosphorus, and carbon chemistry in a northern hardwood ecosystem
1
2001
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
Contrasting biosphere response to climate extremes: revisiting the western Russian Heatwave 2010 and other events
1
2018
... 陆地植被对于长期温度变化具有一定的适应性, 可在一定程度上减少极端事件的破坏性(
The temperature response of soil microbial efficiency and its feedback to climate
1
2013
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Climate-carbon cycle feedback analysis: results from the C4MIP model intercomparison
1
2006
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
How positive is the feedback between climate change and the carbon cycle?
1
2003
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
全球变化与陆地生态系统研究: 回顾与展望
1
2005
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
全球变化与陆地生态系统研究: 回顾与展望
1
2005
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
Recent spring phenology shifts in western Central Europe based on multiscale observations
1
2014
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Declining global warming effects on the phenology of spring leaf unfolding
2
2015
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
... 围绕以上生态系统关键过程, 我们通过梳理已发表的文献资料, 进一步评估了其中10个受关注度较高过程响应气候变暖的置信度(
Nighttime ecology: the “nocturnal problem” revisited
1
2019
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
Drought predisposes pi?on-juniper woodlands to insect attacks and mortality
1
2013
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Phenological response to climate change in China: a meta-analysis
1
2015
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Key ecological responses to nitrogen are altered by climate change
2
2016
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
... ).在增温引起干旱的生态系统中, 有机质矿化速率、磷的扩散速率降低, 植物和微生物对养分的吸收将受到水分胁迫(
Litter decay controlled by temperature, not soil properties, affecting future soil carbon
1
2017
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Attaining whole-ecosystem warming using air and deep-soil heating methods with an elevated CO2 atmosphere
1
2017
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
Biological responses to the press and pulse of climate trends and extreme events
1
2018
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Are treelines advancing? A global meta-analysis of treeline response to climate warming
1
2009
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
1
2013
... IPCC第五次评估报告指出, 全球气温的升高在昼夜间和季节间均呈现出明显的不对称性, 即平均夜间增温幅度大于白天增温幅度(
Ecosystem traits linking functional traits to macroecology
1
2019
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Terrestrial ecosystem carbon dynamics and climate feedbacks
2
2008
... 生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Convergence in the temperature response of leaf respiration across biomes and plant functional types
1
2016
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Non-structural carbon compounds in temperate forest trees
1
2003
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Effects of temperature on the gas exchange of leaves in the light and dark
1
1969
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Determination of world plant formations from simple climatic data
1
1947
... 关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪.古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(
The bioclimatic law
1
1920
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Air temperature optima of vegetation productivity across global biomes
1
2019
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
1
2001
... 自20世纪60年代以来, 国际科学联合会(ICSU)陆续启动了国际生物学计划(IBP)与国际地圈生物圈计划(IGBP), 极大地推动了陆地生态系统响应气候变化的研究.1988年成立的政府间气候变化委员会(IPCC), 陆续出版了多种形式的气候变化评估报告.其中, 第三次IPCC报告(
2
2013
... 围绕以上生态系统关键过程, 我们通过梳理已发表的文献资料, 进一步评估了其中10个受关注度较高过程响应气候变暖的置信度(
... Evidence, agreement and thus confidence of key ecosystem processes in response to climate warming. “Evidence” shows the number of studies that report on ecosystem processes. “Agreement” indicates the percentage of evidence supporting the specific warming response. Confidence is the product of “Evidence” and “Agreement” and is based on the confidence concept in the fifth IPCC report (
Global Warming of 1.5 °C: an IPCC Special Report on the Impacts of Global Warming of 1.5 °C Above Pre-industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change
1
2018
... 关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪.古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(
Research frontiers in climate change: effects of extreme meteorological events on ecosystems
1
2008
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Temperature sensitivity of soil respiration rates enhanced by microbial community response
1
2014
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Increased activity of northern vegetation inferred from atmospheric CO2 measurements
1
1996
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Global shifts in the phenological synchrony of species interactions over recent decades
1
2018
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Long-term sensitivity of soil carbon turnover to warming
1
2005
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Robustness and uncertainties in the new CMIP5 climate model projections
1
2013
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Permafrost carbon-climate feedbacks accelerate global warming
2
2011
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
... ;
Carbon fluxes acclimate more strongly to elevated growth temperatures than to elevated CO2 concentrations in a northern conifer
1
2016
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Plant functional traits have globally consistent effects on competition
1
2016
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Root structure and functioning for efficient acquisition of phosphorus: matching morphological and physiological traits
1
2006
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Warming effects on permafrost ecosystem carbon fluxes associated with plant nutrients
1
2017
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
Soil carbon sensitivity to temperature and carbon use efficiency compared across microbial-ecosystem models of varying complexity
1
2014
... 土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(
More replenishment than priming loss of soil organic carbon with additional carbon input
1
2018
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Modeling the primary productivity of the world//Lieth H, Whittaker RH. Primary Productivity of the Biosphere
1
1975
... 关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪.古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(
Climate warming and biomass accumulation of terrestrial plants: a meta-analysis
1
2010
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Delayed autumn phenology in the Northern Hemisphere is related to change in both climate and spring phenology
1
2016
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Responses of ecosystem carbon cycle to experimental warming: a meta-analysis
1
2013
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
Acclimatization of soil respiration to warming in a tall grass prairie
2
2001
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Parameter identifiability, constraint, and equifinality in data assimilation with ecosystem models
2
2009
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Sustainability of terrestrial carbon sequestration: a case study in Duke Forest with inversion approach
1
2003
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
Assimilation of remotely-sensed leaf area index into a dynamic vegetation model for gross primary productivity estimation
2
2017
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Evolutionary history resolves global organization of root functional traits
1
2018
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Climate warming reduces the temporal stability of plant community biomass production
2017
The variation of productivity and its allocation along a tropical elevation gradient: a whole carbon budget perspective
1
2017
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Disentangling effects of an experimentally imposed extreme temperature event and naturally associated desiccation on Arctic tundra
1
2006
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Drivers and mechanisms of tree mortality in moist tropical forests
1
2018
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Satellite-based evidence for shrub and graminoid tundra expansion in northern Quebec from 1986 to 2010
1
2012
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Using models to guide field experiments: a priori predictions for the CO2 response of a nutrient- and water-limited native Eucalypt woodland
1
2016
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
Using ecosystem experiments to improve vegetation models
3
2015
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
... 整合实验、野外调查观测与模型方法研究陆地生态系统响应与适应气候变暖的思路框架.图中的实验与模型的整合参考了
... Conceptual framework of experiments, field observations, and modeling to study response and adaptation of terrestrial ecosystems to warming. The integration of experiments and models in the figure was adapted from
Macroclimate and lignin control of litter decomposition rates
1
1978
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Soil warming, carbon-nitrogen interactions, and forest carbon budgets
1
2011
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world
3
2017
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
... 生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(
Soil warming and carbon-cycle feedbacks to the climate system
1
2002
... 生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(
Responses of leaf traits to climatic gradients: adaptive variation versus compositional shifts
1
2015
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Plant phenological anomalies in Germany and their relation to air temperature and NAO
1
2003
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
European phenological response to climate change matches the warming pattern
1
2006
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Impacts of nitrogen addition on plant species richness and abundance: a global meta- analysis
1
2019
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Long-term control of Peary caribou numbers by unpredictable, exceptionally severe snow or ice conditions in a non-equilibrium grazing system
1
2009
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
The temperature sensitivity of soil organic matter decomposition is constrained by microbial access to substrates
1
2018
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Decoupling of microbial carbon, nitrogen, and phosphorus cycling in response to extreme temperature events
1
2017
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
History of Botanical Science
1
1981
... 关于陆地生态系统响应与适应气候变化方面的研究, 最早可以追溯到公元前3世纪.古希腊哲学家提奥夫拉斯图斯(Theophrastus)通过植物移栽实验, 发现植物的落叶与常绿特征随着气候条件的变化会发生规律性改变(
Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities
1
2011
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Increased plant growth in the northern high latitudes from 1981 to 1991
1
1997
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Climate-driven increases in global terrestrial net primary production from 1982 to 1999
2003
Global patterns and substrate-based mechanisms of the terrestrial nitrogen cycle
1
2016
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Thermal optimality of net ecosystem exchange of carbon dioxide and underlying mechanisms
3
2012
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
... 陆地植被对于长期温度变化具有一定的适应性, 可在一定程度上减少极端事件的破坏性(
Model-data synthesis for the next generation of forest free-air CO2 enrichment (FACE) experiments
1
2016
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
Community-level phenological response to climate change
1
2013
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Exploring drivers of litter decomposition in a greening Arctic: results from a transplant experiment across a treeline
1
2018
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Influences of species, latitudes and methodologies on estimates of phenological response to global warming
1
2007
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
A globally coherent fingerprint of climate change impacts across natural systems
1
2003
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Recent plant diversity changes on Europe’s mountain summits
1
2012
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Climate-smart soils
1
2016
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Rice yields decline with higher night temperature from global warming
1
2004
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
Asymmetric effects of daytime and night-time warming on Northern Hemisphere vegetation
2
2013
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
... ), 并促进干旱区的植物生长与生态系统生产力(
Litter decomposition in Yellowstone grasslands: the roles of large herbivores, litter quality, and climate
1
2019
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Human-induced nitrogen-phosphorus imbalances alter natural and managed ecosystems across the globe
1
2013
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
A review on the scientific understanding of heatwaves—Their measurement, driving mechanisms, and changes at the global scale
1
2015
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Growing season extension and its impact on terrestrial carbon cycle in the Northern Hemisphere over the past 2 decades
1
2007
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Evidence for a weakening relationship between interannual temperature variability and northern vegetation activity
1
2014
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Leaf onset in the northern hemisphere triggered by daytime temperature
1
2015
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
青藏高原生态系统对气候变化的响应及其反馈
1
2019
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
青藏高原生态系统对气候变化的响应及其反馈
1
2019
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
The whole-soil carbon flux in response to warming
1
2017
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
Water scaling of ecosystem carbon cycle feedback to climate warming
1
2019
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Two decades of terrestrial carbon fluxes from a carbon cycle data assimilation system (CCDAS)
1
2005
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
The world-wide “fast-slow” plant economics spectrum: a traits manifesto
1
2014
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Unexpected reversal of C3 versus C4 grass response to elevated CO2 during a 20-year field experiment
1
2018
... 生物地球化学循环各个过程相互关联且紧密耦合, 因此气候变暖可以通过改变陆地水、氮、磷循环间接调控碳循环和陆地-大气系统之间的反馈作用(
Effects of climate warming on photosynthesis in boreal tree species depend on soil moisture
1
2018
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
From tropics to tundra: global convergence in plant functioning
1
1997
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Ecosystem warming extends vegetation activity but heightens vulnerability to cold temperatures
1
2018
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
Death from drought in tropical forests is triggered by hydraulics not carbon starvation
1
2015
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Deep soil organic matter —A key but poorly understood component of terrestrial C cycle
3
2011
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
... ;
... ).例如, 在深层土壤碳循环过程中, 新的土壤有机碳输入会激发深层土壤有机碳的分解(
Subcontinental heat wave triggers terrestrial and marine, multi-taxa responses
1
2018
... 陆地植被对于长期温度变化具有一定的适应性, 可在一定程度上减少极端事件的破坏性(
The temperature response of C3 and C4 photosynthesis
2
2007
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Carbon dynamics in topsoil and in subsoil may be controlled by different regulatory mechanisms
2
2010
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
... ).而且, 在对气候变化的响应方面, 深层土壤有机碳的机理和浅层土壤有很大的区别, 例如深层土壤面对扰动更加容易矿化(
1
2012
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Climate change and the permafrost carbon feedback
1
2015
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
The effect of permafrost thaw on old carbon release and net carbon exchange from tundra
1
2009
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
Effects of moderate heat stress on photosynthesis: importance of thylakoid reactions, rubisco deactivation, reactive oxygen species, and thermotolerance provided by isoprene
1
2005
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Global warming and terrestrial ecosystems: a conceptual framework for analysis
1
2000
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Divergence of reproductive phenology under climate warming
1
2007
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Model structures amplify uncertainty in predicted soil carbon responses to climate change
2
2018
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Evidence for long-term shift in plant community composition under decadal experimental warming
1
2015
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
General patterns of acclimation of leaf respiration to elevated temperatures across biomes and plant types
1
2015
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
The ecological role of climate extremes: current understanding and future prospects
1
2011
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
A framework for assessing ecosystem dynamics in response to chronic resource alterations induced by global change
1
2009
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Plant respiration and photosynthesis in global-scale models: incorporating acclimation to temperature and CO2
1
2013
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Short-term acclimation to warmer temperatures accelerates leaf carbon exchange processes across plant types
1
2017
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Greenhouse gas mitigation in agriculture
1
2008
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
A meta- analysis of 1119 manipulative experiments on terrestrial carbon-cycling responses to global change
1
2019
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Accelerated increase in plant species richness on mountain summits is linked to warming
1
2018
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Seasons and life cycles
1
2009
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Soil organic carbon pools in the northern circumpolar permafrost region
1
2009
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
Population dynamics of two sympatric antelope species, grey rhebok (Pelea capreolus) and mountain reedbuck (Redunca fulvorufula), in a highveld grassland region of South Africa
1
2006
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Composition of natural organic materials and their decomposition in the soil. IV. The nature and rapidity of decomposition of the various organic complexes in different plant materials, under aerobic conditions
1
1929
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Responses of tree species to heat waves and extreme heat events
1
2015
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Phenological sensitivity to climate across taxa and trophic levels
1
2016
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Carbon-nitrogen interactions regulate climate- carbon cycle feedbacks: results from an atmosphere-ocean general circulation model
1
2009
... 气候变暖深刻地影响了陆地生态系统中碳、氮、磷与水等物质的循环过程及其相互之间的耦合关系.如
Changes in leaf nitrogen and carbohydrates underlie temperature and CO2 acclimation of dark respiration in five boreal tree species
1
1999
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
Causes of variation in soil carbon simulations from CMIP5 Earth system models and comparison with observations
1
2013
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
The relative impacts of daytime and night-time warming on photosynthetic capacity in Populus deltoides
1
2002
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
Going beyond limitations of plant functional types when predicting global ecosystem- atmosphere fluxes: exploring the merits of traits-based approaches
1
2012
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Predicting soil carbon loss with warming
1
2018
... 土壤有机碳是陆地有机碳库的重要组成部分, 也是陆地生态系统反馈未来气候变化的主要不确定性来源(
Widespread increase of tree mortality rates in the western United States
1
2009
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Causal feedbacks in climate change
1
2015
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Inclusion of ecologically based trait variation in plant functional types reduces the projected land carbon sink in an earth system model
1
2015
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Global warming leads to more uniform spring phenology across elevations
1
2018
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Plant community responses to experimental warming across the tundra biome
2
2006
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
A systemic overreaction to years versus decades of warming in a subarctic grassland ecosystem
1
2019
... 在目前大部分模型中, 气候变暖与陆地碳循环之间存在显著的正反馈关系(
Global decomposition experiment shows soil animal impacts on decomposition are climate-dependent
1
2008
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Ecological responses to recent climate change
1
2002
... 随着全球增温趋势的不断加剧, 极端低温和高温事件呈现出破坏性大、突发性强、难以预测等特点(
Photosynthetic overcompensation under nocturnal warming enhances grassland carbon sequestration
2
2009
... 围绕以上生态系统关键过程, 我们通过梳理已发表的文献资料, 进一步评估了其中10个受关注度较高过程响应气候变暖的置信度(
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
Vegetation exerts a greater control on litter decomposition than climate warming in peatlands
1
2015
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Differential responses to changes in growth temperature between trees from different functional groups and biomes: a review and synthesis of data
1
2010
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
Thermal acclimation of photosynthesis: on the importance of adjusting our definitions and accounting for thermal acclimation of respiration
2
2014
... 植物光合与呼吸作用对温度升高都存在短期顺应(acclimation)与长期适应(adaptation)机制.该现象早期发现于植物的光合作用中, 即高温条件促使光合最适温度升高(
... ).其程度在不同植物物种之间存在明显差异(
Response of bog and fen plant communities to warming and water-table manipulations
1
2000
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Quo vadis amphibia? Global warming and breeding phenology in frogs, toads and salamanders
1
2014
... 近年来, 许多研究开始关注植物与动物物候对气候变暖的响应差异(
Representing life in the Earth system with soil microbial functional traits in the MIMICS model
1
2015
... 土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(
Stability of peatland carbon to rising temperatures
1
2016
... 目前, 我们对深层土壤(例如30 cm以下)物质循环过程的理解较浅, 例如仅了解深层土壤物质具有更长的碳滞留时间(
Transient floral change and rapid global warming at the Paleocene-Eocene boundary
1
2005
... 生态学领域通常基于大尺度的观测以及小尺度的控制实验来探究气候变暖在植物群落尺度的生态学效应.大尺度的观测结果显示, 气候变暖正在推动世界范围内物种分布向高纬度和高海拔地区迁移(
Warming experiments underpredict plant phenollogical responses to climate change
1
2012
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
The worldwide leaf economics spectrum
1
2004
... 植物功能性状是与植物生长、生存、竞争和繁殖紧密相关的一系列功能属性(
Biogeochemical and ecological feedbacks in grassland responses to warming
1
2012
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Terrestrial carbon cycle affected by non-uniform climate warming
6
2014
... 围绕以上生态系统关键过程, 我们通过梳理已发表的文献资料, 进一步评估了其中10个受关注度较高过程响应气候变暖的置信度(
... ). The figure was adapted from
... IPCC第五次评估报告指出, 全球气温的升高在昼夜间和季节间均呈现出明显的不对称性, 即平均夜间增温幅度大于白天增温幅度(
... 昼夜的不对称增温会对生态系统产生不同影响, 即白天增温能够在光合最适温度范围内提高植物的碳吸收能力(
... ).截至目前, 关于陆地生态系统如何响应昼夜不对称增温的实验研究仍然局限于草地生态系统(
... ).此外, 不同季节的增温可能会通过“滞后” (
Traceable components of terrestrial carbon storage capacity in biogeochemical models
3
2013
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
... ;
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
Terrestrial ecosystem model performance in simulating productivity and its vulnerability to climate change in the northern permafrost region
4
2017
... 生态系统生产力分配方面的首要问题是陆地生态系统净初级生产力与总初级生产力之间的比例(NPP/GPP)是否随气候变化发生改变.最近,
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
... 生态系统的可持续性发展包含生态系统及其服务在未来会如何变化, 人类的行为决策将如何影响生态系统的发展轨迹等核心问题.回答或解决这些问题需要生态系统的关键过程具有较高的可模拟和可预测能力(
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
Response of ecosystem carbon exchange to warming and nitrogen addition during two hydrologically contrasting growing seasons in a temperate steppe
1
2009
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Global response patterns of terrestrial plant species to nitrogen addition
1
2008
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Independent effects of warming and nitrogen addition on plant phenology in the Inner Mongolian steppe
1
2013
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Interactive effects of warming and nitrogen addition on fine root dynamics of a young subtropical plantation
2
2018
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
Temperature and vegetation seasonality diminishment over northern lands
1
2013
... IPCC第五次评估报告指出, 全球气温的升高在昼夜间和季节间均呈现出明显的不对称性, 即平均夜间增温幅度大于白天增温幅度(
气候变暖对陆地生态系统碳循环的影响
2
2007
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
... 土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(
气候变暖对陆地生态系统碳循环的影响
2
2007
... 针对陆地生态系统响应与适应气候变暖这一新兴领域, 近年来国内已有多个研究团队进行了综述研究(
... 土壤微生物作为土壤中活的有机体系, 是生态系统养分循环和能量流动的重要纽带(
Tundra soil carbon is vulnerable to rapid microbial decomposition under climate warming
1
2016
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Temperature response of photosynthesis in C3, C4, and CAM plants: temperature acclimation and temperature adaptation
1
2014
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Effect of Rubisco activase deficiency on the temperature response of CO2 assimilation rate and Rubisco activation state: insights from transgenic tobacco with reduced amounts of Rubisco activase
1
2009
... 在植物响应与适应温度变化的生理生态学方向, 光合与呼吸作用一直是研究的重点内容.总体而言, 植物光合速率与呼吸速率随着温度的变化呈现出不同的响应曲线.植物的光合速率在最适温度区间(20-30 ℃)达到最大值, 而在过高的温度区间迅速下降(
Community structure and composition in response to climate change in a temperate steppe
1
2011
... 虽然目前已有大量的观测与实验证据说明气候变暖能改变陆地植物群落的结构, 但是对于其生态学机理仍缺乏统一认识.这主要是由于气候变暖不仅通过温度升高直接影响物种的生理生态过程, 还可以通过改变土壤水分条件与养分利用效率等调控植物群落的种内和种间关系, 从而间接影响群落结构的动态.例如, 北半球苔原的湿润区比干燥区具有更高的物种多样性(
Spatiotemporal pattern of gross primary productivity and its covariation with climate in China over the last thirty years
1
2018
... 多尺度生态系统观测数据为生态系统模型发展提供必要的数据和科学理论支持, 而模型是研究生态系统在全球尺度上变化的重要工具(
Decoupling of nitrogen and phosphorus in terrestrial plants associated with global changes
1
2015
... 相对于碳、氮之间的紧密耦合性而言, 气候变化可能导致磷循环与二者发生解耦合的趋势(
Rates of litter decomposition in terrestrial ecosystems: global patterns and controlling factors
1
2008
... 植物凋落物在生态系统的物质循环过程中具有重要作用(
Impacts of climate warming on plants phenology during recent 40 years in China
1
2002
... 植物的展叶、落叶、开花与结果等物候事件对温度变化极为敏感.目前, 中高纬度地区的春季和秋季物候对气候变暖的响应受到了****的广泛关注.大量的地面和遥感观测数据表明气候变暖促使春季物候提前(
Attribution of seasonal leaf area index trends in the northern latitudes with “optimally” integrated ecosystem models
1
2017
... 冻土区贮存了约1 700 Gt土壤碳, 约为大气碳库的2倍, 其微小扰动都会对全球碳循环产生重要影响(
Greening of the Earth and its drivers
1
2016
... 气候变暖对生态系统生产力的影响有明显的水热依赖性, 即在湿润寒冷的生态系统表现为正效应, 但在干旱高温生态系统存在负作用(
