,
,1,*, 韦慧杰1, 陈伟彬1, 朱政财2, 原亚茹1, 张永隆1, 蓝志刚3Effects of plant invasion on soil nitrogen transformation processes and its associated microbes
CHEN Bao-Ming,,1,*, WEI Hui-Jie1, CHEN Wei-Bin1, ZHU Zheng-Cai2, YUAN Ya-Ru1, ZHANG Yong-Long1, LAN Zhi-Gang3通讯作者:
收稿日期:2018-06-09接受日期:2018-11-05网络出版日期:2018-11-20
| 基金资助: |
Received:2018-06-09Accepted:2018-11-05Online:2018-11-20
| Fund supported: |
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陈宝明, 韦慧杰, 陈伟彬, 朱政财, 原亚茹, 张永隆, 蓝志刚. 外来入侵植物对土壤氮转化主要过程及相关微生物的影响. 植物生态学报[J], 2018, 42(11): 1071-1081 doi:10.17521/cjpe.2018.0138
CHEN Bao-Ming, WEI Hui-Jie, CHEN Wei-Bin, ZHU Zheng-Cai, YUAN Ya-Ru, ZHANG Yong-Long, LAN Zhi-Gang.
生物入侵已经成为影响全球生态环境和经济的重大问题。外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(D’Antonio & Vitousek, 1992; Mack et al., 2001; Vilà et al., 2011; Pyšek et al., 2012; D’Antonio & Flory, 2017)。氮(N)循环作为生态系统物质循环的重要组成部分, 其主要过程极易受到生态系统结构与物种组成改变的影响, 外来入侵植物对N循环的影响已成为入侵生态学的研究热点之一(Evans et al., 2001; Knops et al., 2002; Ehrenfeld, 2003; Liao et al., 2008; Castro-Díez et al., 2012; Wang et al., 2015a; McLeod et al., 2016; Jo et al., 2017)。
N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程。目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(Kourtev et al., 1999; Mack et al., 2001; Mack & D’Antonio, 2003; Windham & Ehrenfeld, 2003; Hawkes et al., 2005; Liao et al., 2008; Chen et al., 2009b; Stark & Norton, 2015; McLeod et al., 2016)。
土壤的硝化作用与反硝化作用是两个伴随发生的动态过程。许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(Liao et al., 2008; 刘小文等, 2016), 但也有部分研究发现外来植物入侵区域的土壤N矿化速率低于本地植物生长区域(Evans et al., 2001)。外来入侵植物除了影响硝化过程, 也会因增加反硝化微生物碳源的供给而促进反硝化作用(Rooth et al., 2003; Ehrenfeld, 2010)。由于反硝化作用常发生在厌氧环境, 所以外来入侵植物对湿地生态系统的反硝化作用影响尤为明显。李家兵等(2017)在闽江口鳝鱼滩湿地研究外来入侵植物互花米草(Spartina alterniflora)对N转化的影响, 发现不同季节互花米草入侵对沉积物反硝化速率的影响不同, 在夏季互花米草入侵显著提高了沉积物反硝化速率, 沉积物-水界面N2O交换通量明显升高。然而, 近期Roley等(2018)采用推挽式同位素配对技术(push-pull isotope pairing technique)对比研究了入侵澳大利亚的外来植物芦苇(Phragmites australis)与本地植物长苞香蒲(Typha domingensis)单优群落沉积物的反硝化作用, 发现反硝化作用变化较大, 外来植物芦苇的入侵对反硝化作用的影响并不显著(Roley et al., 2018)。
赵同谦等(2011)综述了外来植物对陆地生态系统N循环的影响途径, 这些影响途径主要包括: 植物的固N作用(Maron & Connors, 1996; Haubensak & D’Antonio, 2011), 植物的N吸收、分配及再利用, 凋落物的分解(Kaproth et al., 2013; 黄成成等, 2018), 土壤生物群落(Dawson & Schrama, 2016)与土壤微环境的改变等。凋落物的分解与养分释放是土壤N转化的主要环节(Ehrenfeld, 2003; Allison & Vitousek, 2004; Hättenschwiler et al., 2005; Jo et al., 2017), 土壤微生物(包括氨氧化微生物)在这些过程中起关键作用(Hawkes et al., 2005; Shannon-Firestone et al., 2015)。外来入侵植物对土壤微生物具有显著的影响(Callaway et al., 2004b; Hawkes et al., 2006; van der Putten et al., 2007), 可见入侵植物通过改变土壤微生物进而影响凋落物的分解与土壤N转化过程。另外, 外来入侵植物往往具有较强的化感作用(Callaway & Aschehoug, 2000; Bais et al., 2003; Hierro & Callaway, 2003; Callaway & Ridenour, 2004), 它们释放的化感物质对N循环过程影响显著(Ridenour & Callaway, 2001; Chen et al., 2009b; Inderjit et al., 2011a, 2011b)。已有许多针对外来植物入侵过程中凋落物的分解和养分释放, 以及入侵植物的化感作用对土壤N转化过程开展的研究。因此, 本文在阐述外来入侵植物对土壤N转化影响的基础上, 重点从外来入侵植物的化感作用与凋落物分解两个方面综述入侵植物对土壤N转化的影响, 并从土壤微生物的角度对入侵植物影响土壤N转化的机制进行了初步探讨。
1 外来入侵植物凋落物与土壤氮转化
凋落物分解与养分释放是生态系统养分循环中的重要过程(Vogt et al., 1991), 它控制着植物养分的再循环以及土壤养分的可利用性(Parker et al., 1984; Koukoura, 1998)。入侵植物通过影响凋落物分解与养分释放过程改变土壤N循环。大多数研究表明, 入侵植物凋落物的分解速率比本地植物凋落物的分解速率快, 导致外来植物入侵会加快系统的养分循环速率, 这主要与入侵植物凋落物的化学组成有关(Allison & Vitousek, 2004; Rothstein et al., 2004; 陈宝明等, 2008; Meisner et al., 2012)。入侵植物凋落物含N量往往比本地种的高, 含N量高的凋落物分解更快, 所以入侵植物的凋落物分解相对更快(Allison & Vitousek, 2004)。Liao等(2008)采用meta分析发现外来入侵植物可以加速被入侵生态系统的凋落物的分解速率, 这会使植物体的N含量上升86%-112%, 植物N含量的增加会进一步提高(+38%)生态系统凋落物的N含量, 进而加快入侵地的凋落物分解与养分的释放。然而, 也有研究表明外来入侵植物的凋落物分解比本地植物的慢。例如, 外来入侵植物Phragmites australis地上部分凋落物的分解速率比本地植物Spartina patens的慢(Windham & Ehrenfeld, 2003); 外来入侵草本植物Aegilops triuncialis使入侵系统的凋落物分解变慢, 进而减缓了入侵系统的养分循环(Rodgers et al., 2008), 入侵植物凋落物分解速率慢可能与外来入侵植物凋落物的木质素含量和多酚含量高有关(Godoy et al., 2010)。外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关。许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(Taylor et al., 1989; Conn & Dighton, 2000), 这说明N含量高的凋落物往往分解较快。当外来入侵植物进入本地群落之后, 外来入侵植物的凋落物会与本地植物的凋落物混合, 通常入侵植物的凋落物N含量较高, 它们与本地植物的凋落物(N含量较低)混合后会加快被入侵生态系统凋落物的分解与养分释放, 这主要与凋落物混合分解的协同效应有关, 也就是说入侵植物与本地植物凋落物混合会产生正的“非加和”效应(Scherer-Lorenzen, 2008; Chapman et al., 2013; Chen et al., 2013; Finerty et al., 2016)。Hättenschwiler等(2005)在其综述中将混合凋落物分解与单一物种凋落物分解的差异归结于以下四个方面: 1)养分含量高的凋落物通常拥有更快的分解速率, 从而会加快混合凋落物中较难分解的凋落物的分解速率; 2)不同凋落物中含有其特异性的化合物(如多酚类物质), 这些化合物可能促进或者抑制凋落物的分解; 3)多个物种的凋落物混合能增加微环境的异质性, 微环境的改变会影响凋落物的分解, 从而导致混合凋落物不同于单一物种凋落物的分解; 4)混合凋落物为土壤动物提供了更丰富的栖息地与食物来源, 同时也能改变土壤动物的行为和取食偏好, 因此土壤动物的改变会影响混合凋落物的分解。
可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(Ehrenfeld, 2003; Liao et al., 2008; Rodgers et al., 2008; Sharma & Raghubanshi, 2009; Chen et al., 2013; Jo et al., 2017), 同时土壤N的可利用性的提高也会促进植物体N含量及凋落物N含量的增加, 会加快入侵地植物的凋落物分解与养分释放, 从而形成“外来入侵植物-加快凋落物分解与养分释放-提高土壤N可利用性-加剧入侵”的正反馈循环效应。
2 外来入侵植物的化感作用对土壤N转化及微生物的影响
许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (Bais et al., 2003; Callaway & Ridenour, 2004; 于兴军等, 2004; Thorpe et al., 2009; 万欢欢等, 2011; Uddin et al., 2017; Warren et al., 2017; Becerra et al., 2018)。外来入侵植物释放的化感物质对土壤N转化过程具有显著影响(Chen et al., 2009b; Thorpe & Callaway, 2011)。例如, 入侵加拿大北部森林的外来植物Kalmia angustifolia凋落物中的单宁显著抑制了微生物酶活性, 减缓了凋落物的分解速度, 进而影响了土壤的N转化速率(Bradley et al., 2000; Joanisse et al., 2007)。有研究发现, 外来入侵植物薇甘菊(Mikania micrantha)水提液显著提高了土壤铵态氮(NH4+)、硝态氮(NO3-)含量和硝化速率(Chen et al., 2009b)。为了进一步阐述改变土壤N转化的化感物质类别是什么, 针对外来入侵植物的特定化感物质进行了相关研究。有研究发现, 入侵北美的外来植物矢车菊(Centaurea stobe)的根系分泌物儿茶素(-catechin)显著降低了土壤的硝化速率(Thorpe & Callaway, 2011); 入侵北美的外来植物虎杖(Polygonum cuspidatum)凋落物中的单宁显著抑制了土壤的N矿化作用(Tharayil et al., 2013)。植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(Chomel et al., 2014, 2016)。我们前期的研究发现, 外来入侵植物薇甘菊释放的化感物质显著改变了本地植物的凋落物分解速率与养分释放量, 进而影响了入侵生态系统的N循环过程(Chen et al., 2007, 2009a)。近期研究发现入侵植物凤仙花(Impatiens glandulifera)造成入侵群落凋落物的分解速率变慢, 这可能与化感物质对分解者(如真菌群落)的影响有关(Helsen et al., 2018)。
探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制。许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(Ni et al., 2006; Watkins et al., 2009; Inderdjit & Putten, 2010; Cipollini et al., 2012; Lorenzo et al., 2013; Zhu et al., 2017; Czaban et al., 2018)。入侵北美的斑点矢车菊(Centaurea maculosa)根部分泌的儿茶酚不仅影响土壤中可培养的细菌数量和特定微生物类群, 而且对根部的病原菌具有抑制作用(Bais et al., 2003); 加拿大一枝黄花(Solidago canadensis)的根系分泌物会抑制土壤中的病原菌, 进而有利于其入侵扩张(Zhang et al., 2009); 铺散矢车菊(Centaurea diffusa)根系分泌的化感物8-羟基喹啉有较强的抗菌能力, 尤其对根际病原微生物产生较大影响(Vivanco et al., 2004; Watkins et al., 2009)。植物释放的化感物质会影响氨氧化微生物的结构与活性, 这是因为土壤微生物利用酚类物质作为碳源, 微生物吸收的酚类物质能够刺激氨氧化细菌(AOB)的活性, 影响氨氧化微生物的结构与活性(Souto et al., 2000), 进而影响土壤的N转化过程(Souto et al., 2000; Ley & Schmidt, 2002)。尽管外来入侵植物的化感作用明显改变了土壤N转化过程(Bradley et al., 2000; Joanisse et al., 2007; Chen et al., 2009a, 2009b; Uddin et al., 2017)与土壤微生物的结构与功能(Inderdjit & Putten, 2010; Lorenzo et al., 2013; Zhu et al., 2017), 但有关外来入侵植物化感作用对氨氧化微生物数量、组成结构与功能的研究还很少, 今后要加强从氨氧化微生物的角度揭示入侵植物的化感作用对N循环影响的机制。
除了认识外来入侵植物的化感作用对土壤微生物的影响(Hierro & Callaway, 2003; Inderjit et al., 2011b; Zubek et al., 2016), 了解土壤微生物对入侵植物化感作用的影响也非常必要。Li等(2017)研究了能够降解紫茎泽兰(Ageratina adenophora)化感物质的微生物的功能, 发现紫茎泽兰入侵的土壤中能够降解化感物质的微生物活性较高, 对化感作用的缓解速度也快于未被入侵的土壤; 并在紫茎泽兰入侵地的土壤微生物中分离出能够降解化感物质的菌株Arthrobacter sp. ZS。说明遭受入侵的土壤在外来植物入侵过程中能够累积降解化感物质的微生物, 进而降低入侵植物的化感作用。未来应加强对降解化感物质微生物的研究, 筛选分离出降解化感物质的菌株, 有望通过它们来降解有害的化感物质, 将有利于入侵植物的防控与入侵地的生态恢复。
3 外来入侵植物对土壤微生物的影响
外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(Kourtev et al., 2002, 2003), 也能改变氨氧化微生物(与N循环密切相关)的结构与功能(Hawkes et al., 2005; McLeod et al., 2016), 还会影响微生物共生体, 进而影响生态系统的N循环过程(Rodríguez-Echeverría et al., 2009; 柏艳芳等, 2011; Dawson & Schrama, 2016)。3.1 外来入侵植物对固氮细菌的影响与反馈作用
外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵。章振亚等(2012)研究了崇明东滩湿地入侵植物互花米草与本地植物芦苇、海三棱藨草(Scirpus × mariqueter)根际固N微生物的多样性, 发现固N菌主要分布在互花米草根际, 而本地植物根际较少; 由于固N微生物能促进入侵植物的土壤养分吸收利用, 所以互花米草根际固N微生物的固N作用对其成功入侵具有重要作用。李会娜等(2009)研究发现外来植物紫茎泽兰入侵提高了土壤自生固N菌、氨氧化细菌和真菌的数量, 提高了土壤养分含量及相关酶活性。说明紫茎泽兰改变了入侵地土壤微生物群落的结构和功能, 这种因微生物的改变引起的土壤酶活性的提高有利于其入侵扩张。另外, 固N的外来植物入侵会显著提高土壤N含量和N的可利用性(Hellmann et al., 2011), 这会进一步加剧外来植物的入侵(Maron & Connors, 1996; Ehrenfeld, 2003; Yelenik et al., 2004)。3.2 外来入侵植物对氨氧化微生物的影响与反馈
土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (Kowalchuk & Stephen, 2001; Hawkes et al., 2005)。隶属变形菌纲的AOB一直被认为是土壤中参与氨氧化作用的唯一微生物类群。然而, 基于宏基因组学发现海洋古菌基因组中含有类似AOB的氨单加氧酶基因(Venter et al., 2004; Treusch et al., 2005)。随后, 研究者从海水中分离培养出氨氧化古菌(ammonia oxidizing archaea, AOA), 证实了氨氧化古菌具有氨氧化作用(Könneke et al., 2005)。AOA广泛存在于森林(Isobe et al., 2012)、草地(Di et al., 2009)、农田(Leininger et al., 2006)等多种陆地生态系统土壤中, 且数量远高于AOB (Leininger et al., 2006)。近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点。野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(Zhang et al., 2011; Piper et al., 2015; McLeod et al., 2016)。Zhang等(2011)调查研究了福建九龙江口红树林自然保护区外来植物互花米草入侵对土壤N转化与氨氧化微生物的影响, 结果表明互花米草入侵不仅改变了AOB群落多样性, 而且显著提高了土壤潜在硝化速率, 这与AOB的数量及其转录表达活性的提高密切相关(Wang et al., 2015b)。Piper等(2015)采用15N同位素分析方法, 研究了加拿大萨斯卡通(Saskatoon)草原外来入侵植物无芒雀麦(Bromus inermis)对入侵地N转化的影响, 发现入侵不仅改变了AOB的丰度, 也改变了AOA的丰度。McLeod等(2016)研究了美国蒙大拿西部草原入侵区域与非入侵区域土壤氨氧化微生物与土壤N的可利用性, 结果表明所有4种入侵植物生长区域的土壤AOB丰度明显比邻近本地植物生长区域的高, 其中3种入侵植物生长区域的硝态氮与潜在硝化速率明显比本地植物生长区域的高。外来入侵草本植物雀麦(Bromus hordeaceus)和燕麦(Avena barbata)总的硝化速率是本地植物的两倍, 入侵导致土壤AOB丰度的增加和组成的改变是其硝化速率增加的原因之一, 说明AOB可能驱动入侵系统土壤的硝化作用, 进而提高土壤NO3-量(Hawkes et al., 2005)。此外, 研究发现外来植物入侵对土壤AOA的影响也较显著, 这种影响随着入侵植物的消退也会减弱。入侵植物柔枝莠竹(Microstegium vimineum)能够改变AOA的群落组成和丰度, 这种影响能够持续2-3年; 进一步分析发现柔枝莠竹入侵对N循环的影响主要与AOA的丰度和群落结构变化有关, 这种影响会随着柔枝莠竹的退化或消失而减弱(Shannon-Firestone et al., 2015)。李科利等(2017)研究了天津市静海县黄顶菊(Flaveria bidentis)入侵重发区土壤与非入侵区土壤AOA的多样性, 发现黄顶菊入侵增加了入侵地根际土AOA的多样性, 这主要与入侵地氨氧化菌群种类的增加有关。
3.3 外来入侵植物对反硝化细菌的影响及其反馈
反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程。外来植物入侵能够改变反硝化细菌的群落结构与功能(Hawkes et al., 2005; Souza-Alonso et al., 2014), Dassonville等(2011)发现外来入侵植物Fallopia spp.能够降低土壤水分含量与土壤反硝化细菌的密度, 进而降低了土壤反硝化酶的活性与反硝化作用, 这种影响能减少被入侵生态系统的N损失(硝态N的淋失与氮氧化物的逸失)。外来植物香蒲(Typha × glauca)的入侵显著提高了土壤无机N含量, 同时也提高了土壤细菌的丰富度和反硝化群落的丰富度(基于nirS基因的测定结果)(Angeloni et al., 2006)。李会娜等(2009)发现, 反硝化细菌数量随着紫茎泽兰入侵程度的加重呈下降趋势。沈荔花等(2007)研究了入侵植物加拿大一枝黄花和本地植物一枝黄花(Solidago decurrens)根际微生物区系, 结果表明加拿大一枝黄花根部土壤中的真菌、细菌和放线菌的数量均高于一枝黄花, 且一枝黄花对根际土壤微生物的生长均表现出抑制效应, 一枝黄花对土壤的反硝化细菌生长的抑制率明显高于加拿大一枝黄花。4 丛枝菌根真菌与外来入侵植物的互相影响
丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(Jansa et al., 2008)。AMF能够影响N的吸收同化、有机N矿化、生物固N、硝化、反硝化等过程, 在N循环中发挥着重要的作用(Veresoglou et al., 2012a, 2012b; 陈永亮等, 2014)。Nuccio等(2013)研究发现AMF Glomus hoi改变了大约10%的细菌群落, 进而加速了凋落物的分解与N的释放。另外, AMF能够通过增强细菌对无机N源的利用, 加速有机N的降解(Johansen et al., 1992)。外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(Walling & Zabinski, 2006; Nijjer et al., 2008)。在土壤有效N低的情况下, AMF显著促进外来入侵植物豚草(Ambrosia artemisiifolia)对N的吸收, 这有利于豚草适应低N生境, 进而促进其成功入侵(黄栋等, 2010)。可见, AMF作为参与N循环的重要微生物, 在外来植物入侵过程中能够改变土壤环境与自身的结构与数量, 进而对外来植物进一步入侵产生反馈作用(Callaway et al., 2004a; 柏艳芳等, 2011)。
外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应。近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系。与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean。另外, 入侵植物的化感作用也会影响植物与AMF的共生关系, Pinzone等(2018)选择AMF型和外生菌根(ECM)型乔木, 研究了外来入侵植物虎杖和欧洲鼠李(Rhamnus cathartica)的化感作用对植物-真菌共生关系的影响, 结果表明入侵植物的化感作用不仅能够直接抑制本地植物种子萌发, 还能够通过减弱本地植物与真菌的共生关系间接地抑制本地植物的生长。此外, 一些具有固N能力的入侵植物在新生境能与当地非特异性固N菌形成共生关系, 与原产地相比这种新的共生关系更能促进外来入侵植物的生长, 进而对入侵产生正反馈效应(Rodríguez-Echeverría et al., 2009; 柏艳芳等, 2011; Callaway et al., 2011)。
5 研究展望
综上所述, 外来植物入侵明显改变了土壤的硝化、矿化过程以及土壤的N水平, 同时也改变了土壤微生物结构与功能, 这些改变对其进一步入侵产生反馈。然而, 更深入的研究还有待进行, 主要包括以下三个方面。(1) 近年来, 从土壤氨氧化微生物(AOA, AOB)角度探讨外来植物入侵对土壤N转化的影响机制已成为研究热点(Shannon-Firestone et al., 2015; Byrnes et al., 2017)。今后要加强对外来植对物成功入侵后AOA与AOB参与土壤N转化过程的差异的研究, 并探究由外来植物入侵引起的非生物环境的改变(如: 土壤pH值、化感物质、其他营养元素)对AOA和AOB的影响及其机制(Xiao et al., 2017)。另外, 应该加强外来植物入侵引起的温室效应气体氮氧化物(NOx)的释放及其机制(Byrnes et al., 2017), 这些研究能够更深入地了解外来植物入侵对生态系统结构与功能的影响。
(2) AMF能够与大部分入侵植物, 尤其是草本入侵植物的根系形成共生关系(Nijjer et al., 2008), 而AMF能够影响N的吸收同化、有机N矿化、生物固N、硝化、反硝化等过程(Veresoglou et al., 2012a)。未来应加强对AMF和氨氧化微生物之间的相互作用的研究, 以期进一步阐述入侵植物对N循环的影响机制。这有助于人们更好地认识土壤N转化过程的机制, 以及对外来植物入侵的反馈作用, 为今后通过养分资源及土壤微生物的调控开展外来植物入侵的防控提供更加充分的科学依据。
(3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(Bradley et al., 2010; Song et al., 2010a, 2010b; Wang et al., 2010; Dukes et al., 2011; Sheppard et al., 2016; Chen et al., 2017; Liu et al., 2018), 外来入侵植物这些生物特性的改变会影响N循环过程, 今后要加强全球变化背景下外来入侵植物对土壤N转化影响的研究, 为评估未来全球变化背景下外来入侵植物的扩散与入侵风险提供依据。
致谢 感谢广州市科技计划重点项目(201607020027)资助。
参考文献 原文顺序
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DOI:10.1007/s00442-004-1679-zURLPMID:15549401 [本文引用: 3]
Physiological traits that contribute to the establishment and spread of invasive plant species could also have impacts on ecosystem processes. The traits prevalent in many invasive plants, such as high specific leaf areas, rapid growth rates, and elevated leaf nutrient concentrations, improve litter quality and should increase rates of decomposition and nutrient cycling. To test for these ecosystem impacts, we measured initial leaf litter properties, decomposition rates, and nutrient dynamics in 11 understory plants from the Hawaiian islands in control and nitrogen + phosphorus fertilized plots. These included five common native species, four of which were ferns, and six aggressive invasive species, including five angiosperms and one fern. We found a 50-fold variation in leaf litter decay rates, with natives decaying at rates of 0.2-2.3 year6301 and invaders at 1.4-9.3 year6301. This difference was driven by very low decomposition rates in native fern litter. Fertilization significantly increased the decay rates of leaf litter from two native and two invasive species. Most invasive litter types lost nitrogen and phosphorus more rapidly and in larger quantities than comparable native litter types. All litter types except three native ferns lost nitrogen after 100 days of decomposition, and all litter types except the most recalcitrant native ferns lost >50% of initial phosphorus by the end of the experiment (204-735 days). If invasive understory plants displace native species, nutrient cycling rates could increase dramatically due to rapid decomposition and nutrient release from invasive litter. Such changes are likely to cause a positive feedback to invasion in Hawai'i because many invasive plants thrive on nutrient-rich soils.
DOI:10.1111/j.1574-6968.2006.00409.xURLPMID:16958855 [本文引用: 1]
Sediments from Cheboygan Marsh, a coastal freshwater wetland on Lake Huron that has been invaded by an emergent exotic plant, Typha 0103 glauca , were examined to assess the effects of invasion on wetland nutrient levels and sediment microbial communities. Comparison of invaded and uninvaded zones of the marsh indicated that the invaded zone showed significantly lower plant diversity, as well as significantly higher aboveground plant biomass and soil organic matter. The sediments in the invaded zone also showed dramatically higher concentrations of soluble nutrients, including greater than 10-fold higher soluble ammonium, nitrate, and phosphate, which suggests that Typha 0103 glauca invasion may be impacting the wetland's ability to remove nutrients. Terminal restriction fragment length polymorphism analyses revealed significant differences in the composition of total bacterial communities (based on 16S-rRNA genes) and denitrifier communities (based on nirS genes) between invaded and uninvaded zones. This shift in denitrifiers in the sediments may be ecologically significant due to the critical role that denitrifying bacteria play in removal of nitrogen by wetlands.
[本文引用: 3]
入侵植物的入侵改变了入侵地生物群落的结构,导致生物多样性的丧 失.丛枝菌根真菌(AMF)作为陆地生态系统中土壤微生物普遍的组成部分,它的种类和组成能够影响入侵植物的生长表现.这种真菌与寄主(入侵植物)特殊的 关系也暗示了AMF能够影响入侵植物的入侵.反之,入侵植物的入侵同样也会影响AMF的群落结构和功能.本文在简要总结我国入侵植物种类及其危害的基础 上,着重探讨了AMF与入侵植物入侵之间的关系,即AMF对入侵植物入侵过程中的作用、入侵植物入侵后如何影响AMF以及两者之间的相互作用机制.
[本文引用: 3]
入侵植物的入侵改变了入侵地生物群落的结构,导致生物多样性的丧 失.丛枝菌根真菌(AMF)作为陆地生态系统中土壤微生物普遍的组成部分,它的种类和组成能够影响入侵植物的生长表现.这种真菌与寄主(入侵植物)特殊的 关系也暗示了AMF能够影响入侵植物的入侵.反之,入侵植物的入侵同样也会影响AMF的群落结构和功能.本文在简要总结我国入侵植物种类及其危害的基础 上,着重探讨了AMF与入侵植物入侵之间的关系,即AMF对入侵植物入侵过程中的作用、入侵植物入侵后如何影响AMF以及两者之间的相互作用机制.
DOI:10.1126/science.1083245URLPMID:12958360 [本文引用: 3]
Here we present evidence that Centaurea maculosa (spotted knapweed), an invasive species in the western United States, displaces native plant species by exuding the phytotoxin (-)-catechin from its roots. Our results show inhibition of native species' growth and germination in field soils at natural concentrations of (-)-catechin. In susceptible species such as Arabidopsis thaliana, the allelo-chemical triggers a wave of reactive oxygen species (ROS) initiated at the root meristem, which leads to a Ca2+signaling cascade triggering genome-wide changes in gene expression and, ultimately, death of the root system. Our results support a "novel weapons hypothesis" for invasive success.
DOI:10.1111/geb.12676URL [本文引用: 1]
Abstract Aim We studied the novel weapons hypothesis in the context of the broadly distributed tree species Eucalyptus globulus . We evaluated the hypothesis that this Australian species would produce stronger inhibitory effects on species from its non-native range than on species from its native range. Location We worked in four countries where this species is exotic (U.S.A., Chile, India, Portugal) and one country where it is native (Australia). Time period 2009 2012. Major taxa studied Plants. Methods We compared species composition, richness and height of plant communities in 20 paired plots underneath E.globulus individuals and open areas in two sites within its native range and each non-native region. We also compared effects of litter leachates of E.globulus on root growth of seedlings in species from Australia, Chile, the U.S.A. and India. Results In all sites and countries, the plant community under E.globulus canopies had lower species richness than did the plant community in open areas. However, the reduction was much greater in the non-native ranges: species richness declined by an average of 51% in the eight non-native sites versus 8% in the two native Australian sites. The root growth of 15 out of 21 species from the non-native range were highly suppressed by E.globulus litter leachates, whereas the effect of litter leachate varied from facilitation to suppression for six species native to Australia. The mean reduction in root growth for Australian plants was significantly lower than for plants from the U.S.A., Chile and India. Main conclusions Our results show biogeographical differences in the impact of an exotic species on understorey plant communities. Consistent with the novel weapons hypothesis, our findings suggest that different adaptations of species from the native and non-native ranges to biochemical compounds produced by an exotic species may play a role in these biogeographical differences.
DOI:10.1016/j.tree.2009.12.003URLPMID:20097441 [本文引用: 1]
, usually promote invasion, other components, such as changing temperature and precipitation, can help or hinder plant invasion. Additionally, experimental studies and models suggest that invasive plants often respond unpredictably to multiple components of global change acting in concert. Such variability adds uncertainty to existing risk assessments and other predictive tools. Here, we review current knowledge about relationships between plant invasion and global change, and highlight research needed to improve forecasts of invasion risk. Managers should be prepared for both expansion and contraction of invasive plants due to global change, leading to increased risk or unprecedented opportunities for restoration.
DOI:10.1016/S0038-0717(00)00039-0URL [本文引用: 2]
Mechanisms responsible for conifer growth “check” on cutovers invaded by Kalmia angustifolia L. in central Newfoundland were studied by examining effects of added Kalmia and balsam fir ( Abies balsamea (L.) Mill) condensed tannins on black spruce humus N dynamics and microbial community development over 10 weeks using microcosms. Because of the silvicultural implications, interactions of tannins with fertiliser N, applied as (NH 4) 2SO 4, were also studied. Both tannin types significantly reduced NH + 4–N leaching, whereas only Kalmia tannins reduced NO 61 3–N leaching, and then only from non-fertilised humus. Tannins did not significantly affect mineral N leaching from fertilised humus. Fertiliser N increased gross N mineralisation rates such that the increase in actively cycling N was many times greater than the increase in N leaching due to fertiliser N addition. Gross N mineralisation rates were higher in fertilised humus amended with tannins, suggesting possible toxicity of tannins on microbes at high N concentrations. Recovery of added tannins in leachate and in post-treatment humus samples was low. Net anaerobic N mineralisation decreased with tannin additions but increased with fertiliser N additions. There were few significant treatment effects on microbial properties derived from humus respirometry. Microbial biomass and basal respiration rates of all treatments declined by 30 and 37% respectively, indicating a general loss of available C during the experiment. The ratio of C mic-to-N mineralised as well as the nutrient deficiency index was lowest in humus amended with Kalmia tannins, suggesting higher microbial N deficiency in this treatment. Utilisation rates of various C sources by microbial communities showed distinctive patterns between pre-treatment and post-treatment humus samples, but did not reveal distinctive patterns among different treatments. Overall, results suggested that (1) condensed tannins decreased mineral N cycling abiotically by binding to and sequestering organic N sources, (2) fertiliser N counteracted negative effects of condensed tannins on humus N cycling, (3) microbial communities were N limited, which prevented abundant leaching of fertiliser N while maintaining fertiliser N in an active pool, and (4) the physiology and functional diversity of soil heterotrophic communities were controlled by C availability but were unaffected by tannin or fertiliser N additions. Further work is needed to determine the ecological importance of Kalmia tannins, relative to tannins produced by other plants, in reducing humus N availability on spruce cutovers.
DOI:10.1016/j.soilbio.2016.12.029URL [本文引用: 2]
61Biological nitrification inhibition-BNI suppresses N2O emission from urine patches.61BNI:Brachiaria humidicolacv. Tully (BT)02>Brachiaria hybridcv. Mulato (BM).61Soil N2O emission was lower from urine patches in soils under BT than BM.61Ammonia oxidizing archaeal nitrifiers were particularly suppressed under BT.61High BNI of tropical forage grasses tightens N cycling in archaea-dominated soils.
DOI:10.1126/science.290.5491.521URLPMID:11039934 [本文引用: 1]
Invading exotic plants are thought to succeed primarily because they have escaped their natural enemies, not because of novel interactions with their new neighbors. However, we find that Centaurea diffusa, a noxious weed in North America, has much stronger negative effects on grass species from North America than on closely related grass species from communities to which Centaurea is native. Centaurea's advantage against North American species appears to be due to differences in the effects of its root exudates and how these root exudates affect competition for resources. Our results may help to explain why some exotic species so successfully invade natural plant communities.
[本文引用: 1]
DOI:10.1890/1540-9295(2004)002[0436:NWISAT]2.0.CO;2URL [本文引用: 2]
DOI:10.1890/02-0775URL [本文引用: 1]
Soil microbes may affect the way exotic invasive plants interact with native neighbors. We investigated the effects of soil fungi on interactions between the invasive weed Centaurea maculosa (spotted knapweed) and six species native to the intermountain prairies of the northwestern United States. We also compared the effect of C. maculosa on the composition of the soil microbial community to that of the native species. In the field, fungicide (Benomyl) reduced AM mycorrhizal colonization of C. maculosa roots by >80%. Fungicide did not significantly reduce non-AM fungi. When grown alone, the biomass of C. maculosa was not affected by the fungicide application. However, depending on the combination of native competitor and fungicide, C. maculosa biomass varied from 10-fold decreases to 1.9-fold increases. In untreated soils, C. maculosa grew larger in the presence of Festuca idahoensis or Koeleria cristata than when alone. When fungicide was applied these positive effects of Festuca and Koeleria on C. maculosa did not occur. A third native grass, Pseudoroegneria spicata, had much stronger competitive effects on C. maculosa than Festuca or Koeleria, and fungicide reduced the competitive effects of Pseudoroegneria. Fungicide increased Centaurea biomass when competing with the forb Gallardia aristata. However, fungicide did not affect the way two other forbs; Achillea millefolium and Linum lewisii, interacted with C. maculosa. Rhizosphere microbial communities in the root zones of the three native bunchgrass species differed from that of C. maculosa. However, despite the strong effects of soil fungi in field interactions and differences in microbial community composition, soil biota from different plant rhizospheres did not affect the growth of C. maculosa in the absence of native competitors in greenhouse experiments. Our results suggest that successful invasions by exotic plant species can be affected by complex and often beneficial effects of local soil microbial communities. These effects were not manifest as simple direct effects, but become apparent only when native plants, invasive plants, and soil microbial communities were interacting at the same time.
DOI:10.1038/nature02322URLPMID:14973484 [本文引用: 1]
Invasive plants are an economic problem and a threat to the conservation of natural systems. Escape from natural enemies might contribute to successful invasion, with most work emphasizing the role of insect herbivores; however, microbial pathogens are attracting increased attention. Soil biota in some invaded ecosystems may promote 'exotic' invasion, and plant-soil feedback processes are also important. Thus, relatively rare species native to North America consistently demonstrate negative feedbacks with soil microbes that promote biological diversity, whereas abundant exotic and native species demonstrate positive feedbacks that reduce biological diversity. Here we report that soil microbes from the home range of the invasive exotic plant Centaurea maculosa L. have stronger inhibitory effects on its growth than soil microbes from where the weed has invaded in North America. Centaurea and soil microbes participate in different plant-soil feedback processes at home compared with outside Centaurea's home range. In native European soils, Centaurea cultivates soil biota with increasingly negative effects on the weed's growth, possibly leading to its control. But in soils from North America, Centaurea cultivates soil biota with increasingly positive effects on itself, which may contribute to the success of this exotic species in North America.
DOI:10.1007/s11104-011-0893-9URL [本文引用: 1]
DOI:10.1371/journal.pone.0062671URLPMID:23658639 [本文引用: 1]
Abstract To what extent microbial community composition can explain variability in ecosystem processes remains an open question in ecology. Microbial decomposer communities can change during litter decomposition due to biotic interactions and shifting substrate availability. Though relative abundance of decomposers may change due to mixing leaf litter, linking these shifts to the non-additive patterns often recorded in mixed species litter decomposition rates has been elusive, and links community composition to ecosystem function. We extracted phospholipid fatty acids (PLFAs) from single species and mixed species leaf litterbags after 10 and 27 months of decomposition in a mixed conifer forest. Total PLFA concentrations were 70% higher on litter mixtures than single litter types after 10 months, but were only 20% higher after 27 months. Similarly, fungal-to-bacterial ratios differed between mixed and single litter types after 10 months of decomposition, but equalized over time. Microbial community composition, as indicated by principal components analyses, differed due to both litter mixing and stage of litter decomposition. PLFA biomarkers a150908090 and cy170908090, which indicate gram-positive and gram-negative bacteria respectively, in particular drove these shifts. Total PLFA correlated significantly with single litter mass loss early in decomposition but not at later stages. We conclude that litter mixing alters microbial community development, which can contribute to synergisms in litter decomposition. These findings advance our understanding of how changing forest biodiversity can alter microbial communities and the ecosystem processes they mediate.
DOI:10.1093/aobpla/plx028URLPMID:5534020 [本文引用: 1]
Abstract Although many studies have documented the effects of global warming on invasive plants, little is known about whether the effects of warming on plant invasion differ depending on the imposed change in different diurnal temperature ranges (DTR). We tested the impact of warming with DTR change on seed germination and seedling growth of eight species in the family Asteraceae. Four of these are invasive (Eupatorium catarium, Mikania micrantha, Biodens pilosa var. radiate, Ageratum conyzoides) in China, and four are native (Sonchus arvensis, Senecios candens, Pterocypsela indica, Eupatorium fortunei). Four temperature treatments were set in growth chambers (three warming by 3 C with different DTRs and control), and experiments were run to mimic wintertime and summertime conditions. The control treatment (Tc) was set to the mean temperature for the corresponding time of year, and the three warming treatments were symmetric (i.e. equal night-and-day) (DTRsym), asymmetric warming with increased (DTRinc) and decreased (DTRdec) DTR. The warming treatments did not affect seed germination of invasive species under any of the conditions, but DTRsym and DTRinc increased seed germination of natives relative to the control, suggesting that warming may not increase success of these invasive plant species via effects on seed germination of invasive plants relative to native plants. The invasive plants had higher biomass and greater stem allocation than the native ones under all of the warming treatments. Wintertime warming increased the biomass of the invasive and wintertime DTRsym and DTRinc increased that of the native plants, whereas summertime asymmetric warming decreased the biomass of the invasives but not the natives. Therefore, warming may not facilitate invasion of these invasive species due to the suppressive effects of summertime warming (particularly the asymmetric warming) on growth. Compared with DTRsym, DTRdec decreased the biomass of both the invasive and native plants, while the asymmetric summer warming treatments (DTRinc and DTRdec) decreased the biomass of the invasive but not the native plants. In addition, wintertime DTRinc did not enhance the biomass of all the plants relative to DTRsym. Our results were obtained in an unrealistic setting; the growth conditions in chambers (e.g. low light, low herbivory, no competition) are quite different from natural conditions (high light, normal herbivory and competition), which may influence the effects of warming on the seedling establishment and growth of both invasive and native plants. Nonetheless, our work highlights the importance of asymmetric warming, particularly in regards to the comparison with the effects of symmetric warming on both invasive and native plants. Conclusions regarding the effects of future warming should be made cautiously because warming with different DTRs may suggest different implications for invasion, and effects of warming may be different in different seasons.
URL [本文引用: 1]
Previous studies showed that extracts of Mikania micrantha influence the balance between various components of soil microflora. Such changes may alter the litter decompostion of native plants in an invaded ecosystem. The effects of aqueous extracts of the invasive plant M micrantha on litter decompositon and nutrient release were studied. Litter of four native woody plants (Ficus virens, Litsea glutinosa, Cinnamomum camphora and Acacia richii) in Southern China was collected. Aqueous extracts of M.micrantha significantly influenced the litter decomposition and nutrient release of test plants spp. The extracts increased the litter decompostion rates of F virens and A. richii but decreased that of L. glutinosa. Besides, the extracts increased the C and N release from litter of F virens, decreased that of L. glutinosa but had no significant effect on A. richii. Without extract treatment, there was significantly negative correlation between litter decomposition rate and litter C: N ratio, while no significant correlation existed in extract treatments, implying that M. micrantha extracts influenced the litter decomposition processes.
[本文引用: 2]
DOI:10.1371/journal.pone.0066289URLPMID:3688783 [本文引用: 2]
A common hypothesis to explain the effect of litter mixing is based on the difference in litter N content between mixed species. Although many studies have shown that litter of invasive non-native plants typically has higher N content than that of native plants in the communities they invade, there has been surprisingly little study of mixing effects during plant invasions. We address this question in south China whereMikania micranthaH.B.K., a non-native vine, with high litter N content, has invaded many forested ecosystems. We were specifically interested in whether this invader accelerated decomposition and how the strength of the litter mixing effect changes with the degree of invasion and over time during litter decomposition. Using litterbags, we evaluated the effect of mixing litter ofM. micranthawith the litter of 7 native resident plants, at 3 ratios: M1(1∶4,66=66exotic:native litter), M2(1∶1) and M3(4∶1,66=66exotic:native litter) over three incubation periods. We compared mixed litter with unmixed litter of the native species to identify if a non-additive effect of mixing litter existed. We found that there were positive significant non-additive effects of litter mixing on both mass loss and nutrient release. These effects changed with native species identity, mixture ratio and decay times. Overall the greatest accelerations of mixture decay and N release tended to be in the highest degree of invasion (mix ratio M3) and during the middle and final measured stages of decomposition. Contrary to expectations, the initial difference in litter N did not explain species differences in the effect of mixing but overall it appears that invasion byM. micranthais accelerating the decomposition of native species litter. This effect on a fundamental ecosystem process could contribute to higher rates of nutrient turnover in invaded ecosystems.
DOI:10.3321/j.issn:0529-6579.2008.06.010URL [本文引用: 1]
(1∶4), M(1∶1) and M(4∶1). After 60—days decay, the litter decomposition rate and nutrient (C, N) release were determined. The results showed that under M, the mixed litter decomposition rate decreased, while, under M, the mixed litter decomposition rate increased. In addition, C released from the mixed litter decreased, while N release increased, and N released the most under M.The increased N release might represent positive feedback to Mikania micrantha invasion.
DOI:10.3321/j.issn:0529-6579.2008.06.010URL [本文引用: 1]
(1∶4), M(1∶1) and M(4∶1). After 60—days decay, the litter decomposition rate and nutrient (C, N) release were determined. The results showed that under M, the mixed litter decomposition rate decreased, while, under M, the mixed litter decomposition rate increased. In addition, C released from the mixed litter decreased, while N release increased, and N released the most under M.The increased N release might represent positive feedback to Mikania micrantha invasion.
DOI:10.1007/s10530-008-9336-9URL [本文引用: 5]
Allelopathy has been regarded as a mechanism for successful exotic plant invasion. However, it is not clear if and what effects of allelopathic substances may exert on soil nutrient. The exotic plant Mikania micrantha H.B.K. ( M. micrantha ) has invaded many forests in south China, and recent studies have suggested it has allelopathic potential for other plants and soil microbial community. Thus, we hypothesized that M. micrantha could influence soil nutrients and N transformation through allelopathy. We measured total C and N, NO 3 61 , NH 4 + and pH of the soil beneath M. micrantha and the adjacent open soil, and then measured the above soil properties after treating soil with 3 concentrations of aqueous extracts of M. micrantha (T 1 : 0.00502g02ml 611 ; T 2 : 0.02502g02ml 611 ; T 3 : 0.10002g02ml 611 ). In addition, a bioassay was conducted to determine the allelopathic potential of the soil beneath M . micrantha . The results showed that M . micrantha significantly affected soil nutrients and N transformation. Soil beneath M. micrantha had inhibitory effects on seed germination and seedling growth of test plant, and had significantly higher C, N, ammonia, net nitrification rate than those of open soil. The plant extracts decreased soil pH, and T 1 decreased it the most, and it increased soil C and N, and T 1 represented the greatest increase in both C and N. The extracts also increased both NO 3 61 and NH 4 + in soil, whereas no significant difference existed among the 3 extract treatments. Compared to the water control, the soil net mineralization rate was higher under T 1 , while lower under T 2 and T 3 . However, the extracts increased the soil nitrification rates under all the treatments (T 1 , T 2 and T 3 ). Our results suggest that the water soluble allelochemicals of M . micrantha improve soil nutrient availability, through which the invasive plant M. micrantha may successfully invade and establish in new habitats.
DOI:10.5846/stxb201309242346URL [本文引用: 1]
作为植物需求量最大的营养元素,氮素是陆地生态系统初级生产力的主要限制因子.丛枝菌根真菌能与地球上 80％以上的陆生植物形成菌根共生体,帮助宿主植物吸收土壤中的P、N等矿质养分.目前,丛枝菌根真菌与氮素循环相关研究侧重于真菌对氮素的吸收形态以及 共生体中氮的传输代谢机制,却忽略了丛枝菌根真菌在固氮过程、矿化与吸收过程、硝化过程、反硝化过程以及氮素淋洗过程等土壤氮素循环过程中所起到的潜在作 用,并且越来越多的证据也表明丛枝菌根真菌是影响土壤氮素循环过程的重要因子.总结了丛枝菌根真菌可利用的氮素形态及真菌的氮代谢转运相关基因的研究现 状;重点分析了丛枝菌根真菌在调控土壤氮素循环过程中的潜在作用以及在生态系统中的重要生态学意义,同时提出了丛枝菌根真菌在土壤氮素循环过程中一些需要 深入研究的问题.
DOI:10.5846/stxb201309242346URL [本文引用: 1]
作为植物需求量最大的营养元素,氮素是陆地生态系统初级生产力的主要限制因子.丛枝菌根真菌能与地球上 80％以上的陆生植物形成菌根共生体,帮助宿主植物吸收土壤中的P、N等矿质养分.目前,丛枝菌根真菌与氮素循环相关研究侧重于真菌对氮素的吸收形态以及 共生体中氮的传输代谢机制,却忽略了丛枝菌根真菌在固氮过程、矿化与吸收过程、硝化过程、反硝化过程以及氮素淋洗过程等土壤氮素循环过程中所起到的潜在作 用,并且越来越多的证据也表明丛枝菌根真菌是影响土壤氮素循环过程的重要因子.总结了丛枝菌根真菌可利用的氮素形态及真菌的氮代谢转运相关基因的研究现 状;重点分析了丛枝菌根真菌在调控土壤氮素循环过程中的潜在作用以及在生态系统中的重要生态学意义,同时提出了丛枝菌根真菌在土壤氮素循环过程中一些需要 深入研究的问题.
DOI:10.1111/1365-2745.12205URL [本文引用: 1]
Over a century of agricultural abandonment across the Mediterranean region has favoured the installation of the pioneer expansionist species Aleppo pine (Pinus halepensis Miller). This species synthesizes a wide range of secondary metabolites that are partially released during needle decomposition, and which can thus affect the ‘brown food chain’. Litter decomposition is a key process connecting ecosystem structure and function, and involving microbial and faunal components.The goal of this study was to determine the effect of chemical compounds from Aleppo pine needles on the litter decomposition process along a gradient of Mediterranean forest secondary succession. Using in situ litterbags, we compared the dynamics of decomposers, particularly the relative contributions of fungal and mesofauna biomass to litter mass loss (calculations based on the measured decomposer biomass, published fungal growth efficiency and mesofauna feeding rate), against the dynamics of secondary metabolites associated with decomposed needles in three successional stages (early, middle and late, i.e. pinewoods that were aged 10, 30 and over 60 years old).Our first key finding was that fungi accounted for the largest portion of overall litter mass loss (60–79%) and detritivorous mesofauna contributed to 8–12%. In the early stage of succession, fungal biomass after 6 months of decomposition was lower than in middle and late stages, and may be responsible for the delay in litter colonization by mesofauna. We linked this result to a clearly longer residence time for phenolic compounds in young pine forest, leading to an overall slowdown in the decomposition process.Synthesis. Litter phenolic content emerged as a key functional trait for predicting litter decomposition, delaying the colonization of litter by decomposers in Mediterranean forest ecosystems. Another key finding is that the relative contributions of fungi and detritivores to needle mass loss were different between the successional stages. From the food-web perspective, the organic matter available for higher trophic levels thus remains unchanged beyond 30 years after pine colonization.
DOI:10.1111/1365-2745.12644URL [本文引用: 1]
Summary A broad and diversified group of compounds, secondary metabolites, are known to govern species interactions in ecosystems. Recent studies have shown that secondary metabolites can also play a major role in ecosystem processes, such as plant succession or in the process of litter decomposition, by governing the interplay between plant matter and soil organisms. We reviewed the ecological role of the three main classes of secondary metabolites and the methodological challenges and novel avenues for their study. We highlight emerging general patterns of the impacts of secondary metabolites on decomposer communities and litter decomposition and argue for the consideration of secondary compounds as key drivers of soil functioning and ecosystem functioning. Synthesis . Gaining a greater understanding of plant oil organisms relationships and underlying mechanisms, including the role of secondary metabolites, could improve our ability to understand ecosystem processes. We outline some promising directions for future research that would stimulate studies aiming to understand the interactions of secondary metabolites across a range of spatio-temporal scales. Detailed mechanistic knowledge could help us to develop models for the process of litter decomposition and nutrient cycling in ecosystems and help us to predict future impacts of global changes on ecosystem functioning.
DOI:10.1007/s10886-012-0133-7URLPMID:22585095 [本文引用: 1]
AbstractStudies of allelopathy in terrestrial systems have experienced tremendous growth as interest has risen in describing biochemical mechanisms responsible for structuring plant communities, determining agricultural and forest productivity, and explaining invasive behaviors in introduced organisms. While early criticisms of allelopathy involved issues with allelochemical production, stability, and degradation in soils, an understanding of the chemical ecology of soils and its microbial inhabitants has been increasingly incorporated in studies of allelopathy, and recognized as an essential predictor of the outcome of allelopathic interactions between plants. Microbes can mediate interactions in a number of ways with both positive and negative outcomes for surrounding plants and plant communities. In this review, we examine cases where soil microbes are the target of allelopathic plants leading to indirect effects on competing plants, provide examples where microbes play either a protective effect on plants against allelopathic competitors or enhance allelopathic effects, and we provide examples where soil microbial communities have changed through time in response to allelopathic plants with known or potential effects on plant communities. We focus primarily on interactions involving wild plants in natural systems, using case studies of some of the world most notorious invasive plants, but we also provide selected examples from agriculturally managed systems. Allelopathic interactions between plants cannot be fully understood without considering microbial participants, and we conclude with suggestions for future research.
DOI:10.1016/S0038-0717(99)00178-9URL [本文引用: 1]
The influence of litter quality on root growth, ectomycorrhizal communities and decay processes was investigated through a litter bag experiment. Litter bags containing either pine needles, oak leaves or oak+pine mix were placed within the O horizon of a lowland pitch pine ( Pinus rigida) forest in the New Jersey Pinelands. Upon retrieval, ingrown pine roots were removed and quantified for total length and percent ectomycorrhizal colonization by morphotype. Phosphatase activity was determined for dominant morphotypes. In addition, litter decay rates and N and P litter content were measured. Mixed litter (oak+pine) had highest total pine root ingrowth. Dominant ectomycorrhizal morphotypes differed in response to litter type. A tuberculate form dominated (35%) in pine litters while distinctly different nontuberculate morphotypes dominated in oak and mixed litters. High phosphatase activity of morphotypes was correlated with high phosphorus immobilization during oak leaf decay. Results indicate that a mix of forest litters (oak and pine) optimizes retention of scarce nutrients such as nitrogen and phosphorus. The diverse chemical environment of these different litter types induces different ectomycorrhizal community development which show functional differences in the way phosphorus is likely to be cycled. The influence of litter type on diversity and function of ectomycorhizae is an important step in identifying linkages between biodiversity of this group and ecosystem functions.
DOI:10.1016/j.soilbio.2018.04.012URL [本文引用: 1]
Secondary metabolites secreted by microbes and plants act as mediators in plant-microbe interactions including nutrient uptake. However, until now very little is known about their role in nutrient assimilation, particularly amino acids, which are important compounds due to their high N content. Here we show that the addition of flavonoid secondary metabolites, derived from clover, to soil changed the bacterial diversity, enhanced the flux of asparagine, and increased the pools of glutamine/glutamate in the soil. This indicates that flavonoids are functionally important qualitative and quantitative components of clover root exudates. Furthermore, the addition of microbial secondary metabolites negatively affected clover uptake of asparagine and plant performance, which demonstrates that microbial competition for nutrients may have multiple physiological targets in the plant. Finally, the detection of intact asparagine in clover roots confirms that amino acid uptake is significant to the plant in agricultural soil. In conclusion, amino-acid flow in the clover rhizosphere can be modified by the effects of clover-derived flavonoids on the bacterial community structure, which affects the flux and pools of amino acids; microbial secondary metabolites, which reduce clover uptake of asparagine; and direct recapture of amino acids by clover.
DOI:10.1111/1365-2745.12879URL [本文引用: 1]
Summary Hundreds of studies have evaluated the dynamics of plant invasions and their impacts on native plant communities and ecosystem functions, but most are limited in duration to only one or a few years. As such, we have a poor understanding of how invader dynamics and impacts change over time. This special feature presents six studies that use literature reviews, field studies and experiments to examine long-term patterns in invader effects on species, communities and ecosystems. All studies in the special feature focus on data collected over multiple years and two studies provide data that cover multiple decades. One study provides a review and framework for understanding how invaders impact plant ycorrhiza mutualisms and two studies focus on long-term ecosystem changes in response to invasion and fire. The next two studies examine how invaders respond to successional change and climate conditions over time, and the final study shows that invaders can shift selection regimes and the evolutionary trajectory of native plant populations. Synthesis . Articles in this special feature demonstrate changes in the dynamics of invasive plant populations and their community and ecosystem impacts over time. Together they illustrate that findings from a snapshot in time may poorly describe years-long outcomes of invasions, and they highlight the need for long-term studies of biological invasions.
DOI:10.1146/annurev.es.23.110192.000431URL [本文引用: 1]
Biological invasions into wholly new regions are a consequence of a far reaching but under-appreciated component of global environmental change, the human-caused breakdown of biogeographic barriers to species dispersal. Human activity moves species from place to place both accidentally and deliberately-and it does so at rates that are without precedent in the last tens of millions of years. As a result, taxa that evolved in isolation from each other are being forced into contact in an instant of evolutionary time.
DOI:10.1007/s10530-011-9954-5URL [本文引用: 1]
Big Asian knotweeds ( Fallopia spp .) are among the most invasive plant species in north-western Europe. We suggest that their success is partially explained by biological and chemical niche construction. In this paper, we explored the microbial mechanisms by which the plant modifies the nitrogen cycle. We found that Fallopia spp . decreased potential denitrification enzyme activity (DEA) by reducing soil moisture and reducing denitrifying bacteria density in the soil. The plant also reduced potential ammonia and nitrite oxydizing bacteria enzyme activities (respectively, AOEA and NOEA) in sites with high AOEA and NOEA in uninvaded situation. Modification of AOEA and NOEA were not correlated to modifications of the density of implicated bacteria. AOB and Nitrobacter -like NOB community genetic structures were significantly different in respectively two and three of the four tested sites while the genetic structure of denitrifying bacteria was not affected by invasion in none of the tested sites. Modification of nitrification and denitrification functioning in invaded soils could lead to reduced nitrogen loss from the ecosystem through nitrate leaching or volatilization of nitrous oxides and dinitrogen and could be considered as a niche construction mechanism of Fallopia.
DOI:10.1111/1365-2745.12619URL [本文引用: 2]
Summary Understanding how invasions by exotic plant species occur has been and still is a fundamental goal in the field of invasion ecology. Recently, research focus has shifted to below-ground mechanisms of invasion, which has provided valuable insights into the role of soil microbes in the invasion process. Research on how soil microbes drive plant invasions has produced a multitude of potential mechanisms and hypotheses, and we have taken this timely opportunity to organize these hypotheses, explore interrelations among them and with other drivers of invasion and identify areas requiring more in-depth study. Synthesis . This special feature brings together current research on soil microbes as drivers and responders of invasion, highlighting the methods that can be used to advance our understanding of how, when and which soil microbes play a role in the invasion process. Further advances in the field can be made by increasing realism in experiments, making wider use of molecular methods and culturing of microbial isolates and considering the importance of microbes relative to other invasion drivers.
DOI:10.1038/ngeo613URL [本文引用: 1]
[本文引用: 1]
DOI:10.1007/s10021-002-0151-3URL [本文引用: 4]
DOI:10.1146/annurev-ecolsys-102209-144650URL [本文引用: 1]
Exotic species affect the biogeochemical pools and fluxes of materials and energy, thereby altering the fundamental structure and function of their ecosystems. Rapidly accumulating evidence from many species of both animal and plant invaders suggests that invasive species often increase pool sizes, particularly of biomass, and promote accelerated flux rates, but many exceptions can be found. Ec...
DOI:10.2307/3060921URL [本文引用: 2]
The introduction of nonnative plant species may decrease ecosystem stability by altering the availability of nitrogen (N) for plant growth. Invasive species can impact N availability by changing litter quantity and quality, rates of N2-fixation, or rates of N loss. We quantified the effects of invasion by the annual grass Bromus tectorum on N cycling in an arid grassland on the Colorado Plateau (USA). The invasion occurred in 1994 in two community types in an undisturbed grassland. This natural experiment allowed us to measure the immediate responses following invasion without the confounding effects of previous disturbance. Litter biomass and the C:N and lignin:N ratios were measured to determine the effects on litter dynamics. Long-term soil incubations (415 d) were used to measure potential microbial respiration and net N mineralization. Plant-available N was quantified for two years in situ with ion-exchange resin bags, and potential changes in rates of gaseous N loss were estimated by measuring denitrification enzyme activity. Bromus invasion significantly increased litter biomass, and Bromus litter had significantly greater C:N and lignin:N ratios than did native species. The change in litter quantity and chemistry decreased potential rates of net N mineralization in sites with Bromus by decreasing nitrogen available for microbial activity. Inorganic N was 50% lower on Hilaria sites with Bromus during the spring of 1997, but no differences were observed during 1998. The contrasting differences between years are likely due to moisture availability; spring precipitation was 15% greater than average during 1997, but 52% below average during spring of 1998. Bromus may cause a short-term decrease in N loss by decreasing substrate availability and denitrification enzyme activity, but N loss is likely to be greater in invaded sites in the long term because of increased fire frequency and greater N volatilization during fire. We hypothesize that the introduction of Bromus in conjunction with land-use change has established a series of positive feedbacks that will decrease N availability and alter species composition.
DOI:10.1111/1365-2745.12602URL [本文引用: 1]
Summary It has long been recognized that leaf traits exert a crucial control on litter decomposition, a key process for nutrient cycling, and that invading species can greatly alter such soil processes via changes in mixed litter trait composition. Trait effects on ecosystem processes are hypothesized to operate via changes in either dominant trait values in the community (often calculated as community-weighted mean trait values; CWM) or trait functional diversity (dissimilarity between species trait values; FD). Few have studied the effects of these community trait components in tandem due to their interdependence. We studied litter mixture decomposition using three exotic and six native European tree species with a range in litter decomposability, to disentangle the unique and combined roles of CWM and FD in explaining net litter mixture mass loss. We showed that while CWM exerted the strongest effect on mass loss, FD modulated its effects, increasing mass loss in mixtures with low mean decomposability and decreasing mass loss in mixtures with high mean decomposability. Litter species identity and native/exotic status explained relatively little additional variation in mass loss after accounting for CWM and FD. We further showed that alterations to CWM and FD were more important than the replacement of a native species with an exotic counterpart in predicting mass loss. Synthesis: Our results indicate that the effect of adding an exotic or losing a native species on litter decomposition rate can be predicted from how a species alters both CWM and FD trait values. This supports the idea that the repercussions of exotic species on ecosystem processes depends on the extent that introduced species bear novel traits or trait values and so on how functionally dissimilar a species is compared to the existing species in the community.
DOI:10.1007/s00442-009-1512-9URLPMID:20155374 [本文引用: 1]
Leaf traits related to the performance of invasive alien species can influence nutrient cycling through litter decomposition. However, there is no consensus yet about whether there are consistent differences in functional leaf traits between invasive and native species that also manifest themselves through their "after life" effects on litter decomposition. When addressing this question it is important to avoid confounding effects of other plant traits related to early phylogenetic divergences and to understand the mechanism underlying the observed results to predict which invasive species will exert larger effects on nutrient cycling. We compared initial leaf litter traits, and their effect on decomposability as tested in standardized incubations, in 19 invasive-native pairs of co-familial species from Spain. They included 12 woody and seven herbaceous alien species representative of the Spanish invasive flora. The predictive power of leaf litter decomposition rates followed the order: growth form > family > status (invasive vs. native) > leaf type. Within species pairs litter decomposition tended to be slower and more dependent on N and P in invaders than in natives. This difference was likely driven by the higher lignin content of invader leaves. Although our study has the limitation of not representing the natural conditions from each invaded community, it suggests a potential slowing down of the nutrient cycle at ecosystem scale upon invasion.
DOI:10.1146/annurev.ecolsys.36.112904.151932URL [本文引用: 2]
DOI:10.1007/s10530-010-9904-7URL [本文引用: 1]
Whether a novel trait of an invader directly contributes to increased establishment of that invader is a relatively unstudied question in plant ecology. Nitrogen (N)-fixing shrubs comprise a significant subset of grassland invaders worldwide, which suggests the potential importance of the novel trait of N-fixation in the invasion process. We indirectly tested the importance of N-fixation in the invasion of Genista monspessulana (French broom) in a California grassland by alleviating N and phosphorus (P) limitation to the grassland matrix. Grassland productivity was co-limited by N and P; N alone did not release the resident vegetation, and did not affect Genista performance. Genista was strongly limited by P: seedlings had more nodules, greater leaf N concentration, and higher growth and survival with P additions. When N was added with P, however, growth of the resident vegetation was 50 70% greater than with N or P alone, accompanied by decreases in Genista performance. This suggests that the advantage conferred to Genista by N-fixation was dampened when the resident vegetation was released from nutrient limitation.
DOI:10.1007/s11104-005-4826-3URL [本文引用: 1]
DOI:10.1111/j.1461-0248.2005.00802.xURL [本文引用: 6]
Plant invasions have dramatic aboveground effects on plant community composition, but their belowground effects remain largely uncharacterized. Soil microorganisms directly interact with plants and mediate many nutrient transformations in soil. We hypothesized that belowground changes to the soil microbial community provide a mechanistic link between exotic plant invasion and changes to ecosystem nutrient cycling. To examine this possible link, monocultures and mixtures of exotic and native species were maintained for 4 years in a California grassland. Gross rates of nitrogen (N) mineralization and nitrification were quantified with 15N pool dilution and soil microbial communities were characterized with DNA-based methods. Exotic grasses doubled gross nitrification rates, in part by increasing the abundance and changing the composition of ammonia-oxidizing bacteria in soil. These changes may translate into altered ecosystem N budgets after invasion. Altered soil microbial communities and their resulting effects on ecosystem processes may be an invisible legacy of exotic plant invasions.
[本文引用: 1]
DOI:10.1002/ecs2.2097URL [本文引用: 1]
Abstract Invasive alien plant effects on ecosystem functions are often difficult to predict across environmental gradients due to the context-dependent interactions between the invader and the recipient communities. Adopting a functional trait-based framework could provide more mechanistic predictions for invasive species' impacts. In this study, we contrast litter decomposition rates among communities with and without the invasive plant Impatiens glandulifera in five regions along a 1600km long latitudinal gradient in Europe. Across this gradient, four functional traits, namely leaf dry matter content (LDMC), specific leaf area (SLA), stem-specific density (SSD), and plant height, are correlated to rates of litter decomposition of standardized rooibos (labile), green tea (recalcitrant), and I.glandulifera litter. Our results show that both invaded and non-invaded plant communities had a higher expression of acquisitive traits (low LDMC and SSD, high SLA) with increasing temperature along the latitudinal gradient, partly explaining the variation in decomposition rates along the gradient. At the same time, invasion shifted community trait composition toward more acquisitive traits across the latitudinal gradient. These trait changes partly explained the increased litter decomposition rates of the labile litter fraction of rooibos and I.glandulifera litter in invaded communities, a shift that was most evident in the warmer study regions. Plant available nitrogen was lower in invaded communities, likely due to high nutrient uptake by I.glandulifera . Meanwhile, the coldest study region was characterized by a reversed effect of invasion on decomposition rates. Here, community traits related to low litter quality and potential allelopathic effects of the invader resulted in reduced litter decomposition rates, suggesting a threshold temperature at which invader effects on litter decomposition turn positive. This study therefore illustrates how functional trait changes toward acquisitive traits can help explain invader-induced changes in ecosystem functions such as increased litter decomposition.
DOI:10.1023/A:1026208327014URL [本文引用: 2]
The primary hypothesis for the astonishing success of many exotics as community invaders relative to their importance in their native communities is that they have escaped the natural enemies that...
URL [本文引用: 1]
为探究克隆繁殖性入侵植物空心莲子草在不同生境下的生长特性,以更好地了解其整体的生存策略,利用15N同位素标定技术评估空心莲子草在陆生(Ⅰ)、湿生(Ⅱ)、水生(Ⅲ)3种不同生境相互转换中的氮素迁移效率,并对不同生境中的空心莲子草生物量分配和表型可塑性差异进行分析研究。结果表明,在不同生境中,空心莲子草氮素迁移量和各构件的生物量均存在显著差异。氮素迁移量存在显著差异(P<0.05),具体生境体现为Ⅱ>Ⅲ>Ⅰ；Ⅱ较Ⅲ平均增长23.32%,较Ⅰ平均增长54.49%。空心莲子草植株总生物量Ⅱ最大,Ⅰ最小。地下生物量投资与生境含水量呈显著负相关,体现为Ⅰ>Ⅱ>Ⅲ,茎生物量投资比叶生物量投资平均高15.57%。在不同生境中,空心莲子草株高和茎节长度均体现为Ⅱ>Ⅲ>Ⅰ,陆生、湿生、水生3种不同生境的母株处理下,Ⅱ株高分别较Ⅲ和Ⅰ增长39%、189%,52%、116%,56%、127%；茎节长度分别增长36%、150%,63%、117%,57%、94%。空心莲子草在不同生境下的氮素迁移量、各构件的生物量以及分配格局表现出的显著差异显示了其在湿生生境下具备更强的氮素迁移利用、表型可塑性和对异质环境的适应能力,揭示了克隆繁殖植物空心莲子草在湿地生境中具有更强的入侵性。该研究可为空心莲子草防控提供理论指导依据。
URL [本文引用: 1]
为探究克隆繁殖性入侵植物空心莲子草在不同生境下的生长特性,以更好地了解其整体的生存策略,利用15N同位素标定技术评估空心莲子草在陆生(Ⅰ)、湿生(Ⅱ)、水生(Ⅲ)3种不同生境相互转换中的氮素迁移效率,并对不同生境中的空心莲子草生物量分配和表型可塑性差异进行分析研究。结果表明,在不同生境中,空心莲子草氮素迁移量和各构件的生物量均存在显著差异。氮素迁移量存在显著差异(P<0.05),具体生境体现为Ⅱ>Ⅲ>Ⅰ；Ⅱ较Ⅲ平均增长23.32%,较Ⅰ平均增长54.49%。空心莲子草植株总生物量Ⅱ最大,Ⅰ最小。地下生物量投资与生境含水量呈显著负相关,体现为Ⅰ>Ⅱ>Ⅲ,茎生物量投资比叶生物量投资平均高15.57%。在不同生境中,空心莲子草株高和茎节长度均体现为Ⅱ>Ⅲ>Ⅰ,陆生、湿生、水生3种不同生境的母株处理下,Ⅱ株高分别较Ⅲ和Ⅰ增长39%、189%,52%、116%,56%、127%；茎节长度分别增长36%、150%,63%、117%,57%、94%。空心莲子草在不同生境下的氮素迁移量、各构件的生物量以及分配格局表现出的显著差异显示了其在湿生生境下具备更强的氮素迁移利用、表型可塑性和对异质环境的适应能力,揭示了克隆繁殖植物空心莲子草在湿地生境中具有更强的入侵性。该研究可为空心莲子草防控提供理论指导依据。
URL [本文引用: 1]
通过温室控制试验,研究了氮碳素添加及丛枝菌根(AM)对外来入侵植物豚草生长的影响.结果表明:氮素添 加对豚草的形态指标、生物量及其分配特征和生长速率均没有显著影响,却使豚草地上器官和根的氮含量显著增加;碳素添加增加了土壤中的有效氮含量,促使豚草 增加营养吸收器官的生物量分配以缓解养分(氮素)胁迫,导致分枝数、总叶面积、比叶面积和叶生物量比明显降低,总生物量显著减少.豚草与AM真菌共生增强 了其适应土壤氮素变化的能力,增加了比叶面积,提高了豚草的资源获取能力,其作用在土壤有效氮含量低时更加明显.AM真菌对豚草适应低氮生境有着重要意 义.
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通过温室控制试验,研究了氮碳素添加及丛枝菌根(AM)对外来入侵植物豚草生长的影响.结果表明:氮素添 加对豚草的形态指标、生物量及其分配特征和生长速率均没有显著影响,却使豚草地上器官和根的氮含量显著增加;碳素添加增加了土壤中的有效氮含量,促使豚草 增加营养吸收器官的生物量分配以缓解养分(氮素)胁迫,导致分枝数、总叶面积、比叶面积和叶生物量比明显降低,总生物量显著减少.豚草与AM真菌共生增强 了其适应土壤氮素变化的能力,增加了比叶面积,提高了豚草的资源获取能力,其作用在土壤有效氮含量低时更加明显.AM真菌对豚草适应低氮生境有着重要意 义.
DOI:10.1016/j.tree.2010.06.006URLPMID:20638747 [本文引用: 2]
Soil communities can have profound effects on invasions of ecosystems by exotic plant species. We propose that there are three main pathways by which this can happen. First, plant oil feedback interactions in the invaded range are neutral to positive, whereas native plants predominantly suffer from negative soil feedback effects. Second, exotic plants can manipulate local soil biota by enhancing pathogen levels or disrupting communities of root symbionts, while suffering less from this than native plants. Third, exotic plants produce allelochemicals toxic to native plants that cannot be detoxified by local soil communities, or that become more toxic following microbial conversion. We discuss the need for integrating these three pathways in order to further understand how soil communities influence exotic plant invasions.
DOI:10.1890/10-0400.1URLPMID:21618911 [本文引用: 1]
Some invasive plant species appear to strongly suppress neighbors in their nonnative ranges but much less so in their native range. We found that in the field in its native range in Mexico, the presence of Ageratina adenophora, an aggressive Neotropical invader, was correlated with higher plant species richness than found in surrounding plant communities where this species was absent, suggesting facilitation. However, in two nonnative ranges, China and India, A. adenophora canopies were correlated with much lower species richness than the surrounding communities, suggesting inhibition. Volatile organic compound (VOC) signals may contribute to this striking biogeographical difference and the invasive success of A. adenophora. In controlled experiments volatiles from A. adenophora litter caused higher mortality of species native to India and China, but not of species native to Mexico. The effects of A. adenophora VOCs on seedling germination and growth did not differ between species from the native range and species from the nonnative ranges of the invader. Litter from A. adenophora plants from nonnative populations also produced VOCs that differed quantitatively in the concentrations of some chemicals than litter from native populations, but there were no chemicals unique to one region. Biogeographic differences in the concentrations of some volatile compounds between ranges suggest that A. adenophora may be experiencing selection on biochemical composition in its nonnative ranges.
DOI:10.1016/j.tree.2011.08.003URLPMID:21920626 [本文引用: 2]
Plants can release chemicals into the environment that suppress the growth and establishment of other plants in their vicinity: a process known as ‘allelopathy’. However, chemicals with allelopathic functions have other ecological roles, such as plant defense, nutrient chelation, and regulation of soil biota in ways that affect decomposition and soil fertility. These ecosystem-scale roles of allelopathic chemicals can augment, attenuate or modify their community-scale functions. In this review we explore allelopathy in the context of ecosystem properties, and through its role in exotic invasions consider how evolution might affect the intensity and importance of allelopathic interactions.
DOI:10.1111/j.1574-6941.2011.01294.xURLPMID:22224831 [本文引用: 1]
Nitrification has been believed to be performed only by autotrophic ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) until the recent discovery of ammonia-oxidizing archaea (AOA). Meanwhile, it has been questioned whether AOB are significantly responsible for NH3 oxidation in acidic forest soils. Here, we investigated nitrifying communities and their activity in highly acidified soils of three subtropical forests in southern China that had received chronic high atmospheric N deposition. Nitrifying communities were analyzed using PCR- and culture (most probable number)-based approaches. Nitrification activity was analyzed by measuring gross soil nitrification rates using a 15N isotope dilution technique. AOB were not detected in the three forest soils: neither via PCR of 16S rRNA and ammonia monooxygenase (amoA) genes nor via culture-based approaches. In contrast, an extraordinary abundance of the putative archaeal amoA was detected (3.2 0103 1080900091.2 0103 109 g soil0908081). Moreover, this abundance was correlated with gross soil nitrification rates. This indicates that amoA-possessing archaea rather than bacteria were predominantly responsible for nitrification of the soils. Furthermore, sequences of the genus Nitrospira, a dominant group of soil NOB, were detected. Thus, nitrification of acidified subtropical forest soils in southern China could be performed by a combination of AOA and NOB.
DOI:10.1111/j.1469-8137.2007.02294.xURLPMID:18042204 [本文引用: 1]
090004 Arbuscular mycorrhizal fungal (AMF) communities were established in pots using fungal isolates from a single field in Switzerland. It was tested whether multispecies mixtures provided more phosphorus and supported greater plant growth than single AMF species. 090004 Two host plants, medic ( Medicago truncatula ) and leek ( Allium porrum ), were inoculated with three AMF species ( Glomus mosseae , G. claroideum and G. intraradices ), either separately or in mixtures. The composition of the AMF communities in the roots was assessed using real-time PCR to determine the copy number of large ribosomal subunit genes. 090004 Fungal communities in the roots were usually dominated by one AMF species ( G. mosseae ). The composition of the communities depended on both plant identity and the time of harvest. Leek colonized by a mixture of G. claroideum and G. intraradices acquired more P than with either of the two AMF separately. 090004 Direct evidence is provided for functional complementarity among species within the AMF community colonizing a single root system. Competition among the species poses a major challenge in interpreting experiments with mixed inoculations, but this is greatly facilitated by use of real-time PCR.
DOI:10.1111/1365-2745.12732URL [本文引用: 3]
Abstract Although it is widely believed that non-native invasive species threaten the functional integrity of forest ecosystems, their impact on important ecosystem processes such as nitrogen (N) cycling is not well understood. To examine how invasive species alter ecosystem N dynamics, we established monocultures of five phylogenetic pairs of native and non-native invasive understory woody species common to Eastern U.S. forests. After three years, we found invaders increased N cycling by enhancing the flow of N to the soil through greater litter N production and litter N content, and increased the uptake of available soil N, via greater fine root production and specific root length. Synthesis Our results highlight the importance of linking above- and below-ground processes to better understand invader impacts on ecosystem nutrient processes. The rapid shifts in soil N processes as a result of invader dominance observed in our study suggest that invaders may be an important driver of forest ecosystem functioning.
DOI:10.1111/j.1469-8137.2007.02113.xURLPMID:17635228 [本文引用: 2]
090004 Kalmia angustifolia is an ericaceous shrub that can rapidly spread on recently harvested boreal forest sites, causing a slow-down in soil nutrient cycling and reduced growth of spruce seedlings. It has been hypothesized that tannins released from Kalmia litter suppress soil enzyme activity, and are thus important in controlling ecosystem structure and processes. 090004 Here the effects of different concentrations of tannins extracted from both Kalmia and black spruce ( Picea mariana ) foliage were tested on enzyme activities of soil extracts. Then the effects of various Kalmia 090009black spruce litter mixtures on soil enzyme activity were investigated. Lastly, the correlation between Kalmia cover in the field and soil enzyme activity was measured. 090004 Both tannin types suppressed 0205-glucosidase and acid phosphatase activities, and the magnitude of these effects was concentration-dependent. 0205-glucosidase and amidase activity decreased linearly with an increasing Kalmia : spruce litter ratio added to soil. A field survey of 24 sites revealed a negative relationship between percentage Kalmia cover and 0205-glucosidase activity. 090004 Collectively, results of the three experiments converge to support the claim that enzyme inhibition by litter tannins has evolved as an important mechanism controlling ecosystem processes and structure following Kalmia invasion on recently disturbed forest sites.
DOI:10.1111/j.1469-8137.1992.tb04232.xURL [本文引用: 1]
Hyphal transport of nitrogen from a 15 N-labelled ammonium source by a VA-mycorrhizal fungus was studied under controlled experimental conditions. Cucumis sativus L. cv. Aminex (F1 hybrid) was grown alone or together with Glomus intraradices Schenck and Smith in containers with a hyphal compartment separated from the rooting medium by a fine nylon mesh. Lateral movement of the applied 15 N towards the roots was minimized by using a nitrification inhibitor (N-serve) and a hyphal buffer compartment. Recovery of 15 N by mycorrhizal and non-mycorrhizal plants was 6 and 0%, respectively, after a labelling period of 23 days. The corresponding figures, without N-serve added, were 4 and 7%. A prolongation of the labelling period by 8 days (N-serve applied) resulted in an increase in the 15 N recovery by mycorrhizal plants to 30% of the applied 15 N. Non-mycorrhizal plants contained only traces of 15 N. The external hyphae depleted the soil in the hyphal compartment efficiently for inorganic N. In contrast, hyphal compartments of control containers still contained considerable amounts of inorganic N. The 15 N assimilated by the external hyphae in one hyphal compartment was not translocated in significant amounts to the external hyphae in another hyphal compartment. The possible implication of this for inter-plant N transfer by VA hyphal connections is discussed.
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DOI:10.1046/j.1461-0248.2002.00332.xURL [本文引用: 1]
Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positive feedbacks on the rate of nitrogen cycling. Alternatively, plant species can also control the inputs and losses of nitrogen from ecosystems.Our current understanding of litter decomposition shows that most nitrogen present within litter is not released during decomposition but incorporated into soil organic matter. This nitrogen retention is caused by an increase in the relative nitrogen content in decomposing litter and a much lower carbon-to-nitrogen ratio of soil organic matter. The long time lag between plant litter formation and the actual release of nitrogen from the litter results in a bottleneck, which prevents feedbacks of plant quality differences on nitrogen cycling. Instead, rates of gross nitrogen mineralization, which are often an order of magnitude higher than net mineralization, indicate that nitrogen cycling within ecosystems is dominated by a microbial nitrogen loop. Nitrogen is released from the soil organic matter and incorporated into microbial biomass. Upon their death, the nitrogen is again incorporated into the soil organic matter. However, this microbial nitrogen loop is driven by plant-supplied carbon and provides a strong negative feedback through nitrogen cycling on plant productivity. Evidence supporting this hypothesis is strong for temperate grassland ecosystems. For other terrestrial ecosystems, such as forests, tropical and boreal regions, the data are much more limited. Thus, current evidence does not support the view that differences in the efficiency of plant nitrogen use lead to positive feedbacks.In contrast, soil microbes are the dominant factor structuring ecosystem nitrogen cycling. Soil microbes derive nitrogen from the decomposition of soil organic matter, but this microbial activity is driven by recent plant carbon inputs. Changes in plant carbon inputs, resulting from plant species shifts, lead to a negative feedback through microbial nitrogen immobilization. In contrast, there is abundant evidence that plant species impact nitrogen inputs and losses, such as: atmospheric deposition, fire-induced losses, nitrogen leaching, and nitrogen fixation, which is driven by carbon supply from plants to nitrogen fixers. Additionally, plants can influence the activity and composition of soil microbial communities, which has the potential to lead to differences in nitrification, denitrification and trace nitrogen gas losses. Plant species also impact herbivore behaviour and thereby have the potential to lead to animal-facilitated movement of nitrogen between ecosystems.Thus, current evidence supports the view that plant species can have large impacts on ecosystem nitrogen cycling. However, species impacts are not caused by differences in plant quantity and quality, but by plant species impacts on nitrogen inputs and losses.
DOI:10.1038/nature03911URLPMID:16177789 [本文引用: 1]
Abstract For years, microbiologists characterized the Archaea as obligate extremophiles that thrive in environments too harsh for other organisms. The limited physiological diversity among cultivated Archaea suggested that these organisms were metabolically constrained to a few environmental niches. For instance, all Crenarchaeota that are currently cultivated are sulphur-metabolizing thermophiles. However, landmark studies using cultivation-independent methods uncovered vast numbers of Crenarchaeota in cold oxic ocean waters. Subsequent molecular surveys demonstrated the ubiquity of these low-temperature Crenarchaeota in aquatic and terrestrial environments. The numerical dominance of marine Crenarchaeota--estimated at 10(28) cells in the world's oceans--suggests that they have a major role in global biogeochemical cycles. Indeed, isotopic analyses of marine crenarchaeal lipids suggest that these planktonic Archaea fix inorganic carbon. Here we report the isolation of a marine crenarchaeote that grows chemolithoautotrophically by aerobically oxidizing ammonia to nitrite--the first observation of nitrification in the Archaea. The autotrophic metabolism of this isolate, and its close phylogenetic relationship to environmental marine crenarchaeal sequences, suggests that nitrifying marine Crenarchaeota may be important to global carbon and nitrogen cycles.
DOI:10.1016/s1146-609x(98)80015-5URL [本文引用: 1]
The rate of litter loss, and the release of N, P, K, Ca during litter decomposition of two C4 plants (Dichanthium ischaemum L. and Chrysopogon gryllus L.) and one C3 plant (Festuca ovina H. ) were studied for 24 months. This was achieved by placing leaf and culm litter in nylon screen bags close to the soil surface, sampling every three months to mease the changes in litter weight and chemical composition during the experimental period. Litter decomposition was faster during the first 12 months for both leaves and culms of all species. The order was D. ischaemum > F. ovina > C. gryllus. The mean rate litter loss for the 12 and 24 month period was similar for leaf and culm litter. Nitrogen accumulation was observed during the entire experimental period for all species. Phosphorus release had occurred during the experimental period in the decreasing order: C. gryllus > D. ischaemum > F. ovina. Potassium release was observed after 12 and 24 months in the decreasing order D. ischaemum > C. gryllus > F. ovina, while calcium was accumulating. The decomposition rates were similar for C4 and C3 plants and their contribution to nutrient cycling depended on the release of the various elements during decomposition.
DOI:10.1023/A:1010048909563URL [本文引用: 1]
DOI:10.2307/3071850URL [本文引用: 1]
Exotic plant species are increasingly becoming the focus of research and have been identified as a component of human-induced global change. Successful invaders may alter soil conditions, but the effect of exotic species on soil microbial communities has not been studied. We studied two exotic understory plant species (Japanese barberry [Berberis thunbergii] and Japanese stilt grass [Microstegium vimineum]) in hardwood forests in northern New Jersey, USA. We sampled bulk and rhizosphere soils under the two exotic species, as well as under a co-occurring native species (blueberry [Vaccinium spp.]). We indexed the structure (by measuring phospholipid fatty acid [PLFA] profiles) and function (by measuring enzyme activities and substrate-induced respiration [SIR] profiles) of microbial communities in the sampled soils. Soils under the three species differed in microbial community structure and function. These differences were observed in both the rhizosphere and bulk soil samples. Differences in the structural variables were correlated to differences in the functional variables as demonstrated by canonical correlation analysis. These results indicate that successful exotic invasive species can have profound effects on the microbial community of the soil.
DOI:10.1016/S0038-0717(03)00120-2URL [本文引用: 1]
Invasions of exotic plant species are among the most pervasive and important threats to natural ecosystems, however, the effects of plant invasions on soil processes and the soil biota have rarely been investigated. We grew two exotic and a native under-story plant species in the same mineral soil from a non-invaded forest stand in order to test whether observed differences in the field could be experimentally produced in the greenhouse. We characterized changes in the soil microbial community structure (as indexed by PLFAs) and function (as indexed by enzyme activities and SIR), as well as changes in potential nitrogen mineralization rates. We found that the invasion of two very dissimilar exotic species into the under-story of deciduous forests in eastern North America can rapidly cause changes in most of the studied soil properties. At the end of the three-month incubation, soils under the exotic species had significantly different PLFA, enzyme and SIR profiles than both initial soils and soils where native shrubs had been grown. We also observed a significant increase in pH and nitrification rates under one of the exotic plants. Such changes in the soil are potentially long-term (e.g. changes in soil pH) and are therefore likely to promote the re-invasion of these and other exotics. Both management of exotic plant invasions and the restoration of native communities must take into account exotic species effects on the soil.
DOI:10.1146/annurev.micro.55.1.485URL [本文引用: 1]
DOI:10.1038/nature04983URLPMID:16915287 [本文引用: 2]
Ammonia oxidation is the first step in nitrification, a key process in the global nitrogen cycle that results in the formation of nitrate through microbial activity. The increase in nitrate availability in soils is important for plant nutrition, but it also has considerable impact on groundwater pollution owing to leaching. Here we show that archaeal ammonia oxidizers are more abundant in soils than their well-known bacterial counterparts. We investigated the abundance of the gene encoding a subunit of the key enzyme ammonia monooxygenase (amoA) in 12 pristine and agricultural soils of three climatic zones. amoA gene copies of Crenarchaeota (Archaea) were up to 3,000-fold more abundant than bacterial amoA genes. High amounts of crenarchaeota-specific lipids, including crenarchaeol, correlated with the abundance of archaeal amoA gene copies. Furthermore, reverse transcription quantitative PCR studies and complementary DNA analysis using novel cloning-independent pyrosequencing technology demonstrated the activity of the archaea in situ and supported the numerical dominance of archaeal over bacterial ammonia oxidizers. Our results indicate that crenarchaeota may be the most abundant ammonia-oxidizing organisms in soil ecosystems on Earth.
DOI:10.1016/S0038-0717(02)00032-9URL [本文引用: 1]
these questions. The soils came from high elevation mountain talus slopes, which are a poorly studied ex- Microbial biomass generally increases with organic matter accre- treme environment. tion in soils, but little is known about the relative proportion of specific microbial functional groups that compose the biomass. We measured Mountain talus slopes are composed of unconsoli- the biomass of... [Show full abstract]
DOI:10.3864/j.issn.0578-1752.2009.11.025URL [本文引用: 2]
【目的】通过比较外来植物紫茎泽兰不同入侵程度样地的土壤微生物、酶活性及肥力变化,以期揭 示外来植物入侵对土壤生态的影响机制。【方法】本文采用传统培养的方法研究了紫茎泽兰对入侵地土壤微生物群落的结构变化;比较了入侵对8种土壤肥力因子和 3种土壤酶活性的影响。【结果】紫茎泽兰入侵提高了土壤有机质、NO3--N、NH4＋-N、有效磷、有效钾和土壤脲酶、磷酸酶和蔗糖酶的含量。重度入侵 生境中铵态氮含量最高达53.00mg·kg^-1,分别是空白对照土、混生当地植物土和单一当地植物土的14.1、9.9和5.9倍。脲酶含量在重度为 2.87,显著高于当地植物区,并为空白区的3.9倍。培养结果表明紫茎泽兰入侵提高了土壤自生固氮菌、氨氧化细菌和真菌的数量。【结论】紫茎泽兰改变了 入侵地土壤微生物群落结构和功能,暗示着微生物的改变引起土壤酶活性的改变进而影响了土壤肥力,形成对自身生长有利的微生态环境以利于入侵扩张。
DOI:10.3864/j.issn.0578-1752.2009.11.025URL [本文引用: 2]
【目的】通过比较外来植物紫茎泽兰不同入侵程度样地的土壤微生物、酶活性及肥力变化,以期揭 示外来植物入侵对土壤生态的影响机制。【方法】本文采用传统培养的方法研究了紫茎泽兰对入侵地土壤微生物群落的结构变化;比较了入侵对8种土壤肥力因子和 3种土壤酶活性的影响。【结果】紫茎泽兰入侵提高了土壤有机质、NO3--N、NH4＋-N、有效磷、有效钾和土壤脲酶、磷酸酶和蔗糖酶的含量。重度入侵 生境中铵态氮含量最高达53.00mg·kg^-1,分别是空白对照土、混生当地植物土和单一当地植物土的14.1、9.9和5.9倍。脲酶含量在重度为 2.87,显著高于当地植物区,并为空白区的3.9倍。培养结果表明紫茎泽兰入侵提高了土壤自生固氮菌、氨氧化细菌和真菌的数量。【结论】紫茎泽兰改变了 入侵地土壤微生物群落结构和功能,暗示着微生物的改变引起土壤酶活性的改变进而影响了土壤肥力,形成对自身生长有利的微生态环境以利于入侵扩张。
DOI:10.13671/j.hjkxxb.2016.0234URL [本文引用: 2]
2014年4、7、10月和2015年1月在闽江口鳝鱼滩湿地选择未被入侵的短叶茳芏(Cyperus malaccensis)群落(A)、互花米草入侵斑块边缘(B)以及互花米草(Spartina alterniflora)入侵斑块中央(C)为研究对象,基于时空互代研究方法,探讨互花米草入侵序列下湿地沉积物硝化-反硝化变化规律.结果表明:在互花米草入侵序列中,湿地沉积物硝化速率为0.19~1.66μmol·m~(-2)·h~(-1),反硝化速率为12.41~27.19μmol·m~(-2)·h~(-1).沉积物硝化-反硝化作用存在明显的季节变化,硝化速率表现为夏季春季秋季冬季,反硝化速率表现为夏季秋季冬季春季;入侵不同状态下,沉积物硝化速率表现为BCA,反硝化速率表现为CBA.互花米草入侵提高了沉积物-水界面N_2O交换通量.互花米草入侵引起的沉积物pH、NH_4~+-N、含水量、容重和电导率等理化性质的改变是导致不同入侵阶段沉积物硝化-反硝化速率以及N_2O释放差异的重要原因.
DOI:10.13671/j.hjkxxb.2016.0234URL [本文引用: 2]
2014年4、7、10月和2015年1月在闽江口鳝鱼滩湿地选择未被入侵的短叶茳芏(Cyperus malaccensis)群落(A)、互花米草入侵斑块边缘(B)以及互花米草(Spartina alterniflora)入侵斑块中央(C)为研究对象,基于时空互代研究方法,探讨互花米草入侵序列下湿地沉积物硝化-反硝化变化规律.结果表明:在互花米草入侵序列中,湿地沉积物硝化速率为0.19~1.66μmol·m~(-2)·h~(-1),反硝化速率为12.41~27.19μmol·m~(-2)·h~(-1).沉积物硝化-反硝化作用存在明显的季节变化,硝化速率表现为夏季春季秋季冬季,反硝化速率表现为夏季秋季冬季春季;入侵不同状态下,沉积物硝化速率表现为BCA,反硝化速率表现为CBA.互花米草入侵提高了沉积物-水界面N_2O交换通量.互花米草入侵引起的沉积物pH、NH_4~+-N、含水量、容重和电导率等理化性质的改变是导致不同入侵阶段沉积物硝化-反硝化速率以及N_2O释放差异的重要原因.
DOI:10.13758/j.cnki.tr.2017.05.029URL [本文引用: 1]
为了明确入侵植物黄顶菊对土壤氮循环关键过程硝化作用的影响机制,本研究通过对其入侵地和未入侵地、根围土和根际土氨氧化古菌(ammonia-oxidizing archaea,AOA)的群落多样性分析,探讨了AOA对黄顶菊入侵的响应规律.结果表明:黄顶菊入侵增加了入侵地根围土AOA的多样性,AOA的Shannon指数表现为:入侵地根围土>入侵地根际土>未入侵地土壤,且差异显著.铵态氮含量与pH的变化都会影响土壤AOA的群落结构.系统发育树分析表明,土壤AOA主要隶属于氨氧化古菌的Nitrososphaera cluster.黄顶菊入侵导致的AOA的多样性水平的提升主要是由于入侵地氨氧化菌群种类增加所致.
DOI:10.13758/j.cnki.tr.2017.05.029URL [本文引用: 1]
为了明确入侵植物黄顶菊对土壤氮循环关键过程硝化作用的影响机制,本研究通过对其入侵地和未入侵地、根围土和根际土氨氧化古菌(ammonia-oxidizing archaea,AOA)的群落多样性分析,探讨了AOA对黄顶菊入侵的响应规律.结果表明:黄顶菊入侵增加了入侵地根围土AOA的多样性,AOA的Shannon指数表现为:入侵地根围土>入侵地根际土>未入侵地土壤,且差异显著.铵态氮含量与pH的变化都会影响土壤AOA的群落结构.系统发育树分析表明,土壤AOA主要隶属于氨氧化古菌的Nitrososphaera cluster.黄顶菊入侵导致的AOA的多样性水平的提升主要是由于入侵地氨氧化菌群种类增加所致.
DOI:10.1111/1365-2664.12878URL
1. Soil microbes are important in mediating allelopathic interactions between invasive and native plants in the field. However, it was not known how these interactions vary in the process of biological invasions and the effects of soil microbes; this knowledge may facilitate understanding the dynamics and mechanisms of biological invasions and managing invaded ecosystems. 2. We conducted competition and seed germination experiments to determine the allelopathic effects of Ageratina adenophora in soils from 42 sites with varying abundances of the invasive plant. Then we isolated the microbes that could degrade the allelochemicals of the invasive plant and tested their functions. 3. In both experiments, the allelopathic effects of the invasive plant were much stronger in soils from non-invaded sites than in soils from invaded sites. Activities of the allelochemical-degrading microbes were higher and degradation of the allelochemicals of the invasive plant was faster in soils from invaded sites than in soils from non-invaded sites. In living soils from 30 sites with increasing abundance of A. adenophora, the allelopathic effects of the invasive plant decreased and degradation of the allelochemicals and activity of the allelochemicaldegrading microbes gradually increased. 4. Two bacterial strains were isolated from the soils. Inoculation of Arthrobacter sp. ZS, which was isolated from soil invaded by A. adenophora, greatly increased the degradation of the allelochemicals, thereby decreasing its allelopathic effects. 5. Synthesis and applications. Our results indicate that soils may accumulate microbes that can degrade allelochemicals in the process of biological invasions, gradually reducing the allelopathic effects of invasive species. The effects of soil microbes should be considered when studying dynamics and mechanisms of biological invasions. Application of allelochemicaldegrading microbes may facilitate ecological restoration of invaded or newly disturbed ecosystems by alleviating allelopathic inhibition of invasive plants on native plants.
DOI:10.1111/nph.2008.177.issue-3URL [本文引用: 4]
DOI:10.1038/s41598-018-21546-zURLPMID:29453340 [本文引用: 1]
Galinsoga quadriradiata, an annual herbaceous plant originating in Central and South America, has caused great harm to agriculture and natural communities in China recently. However, the distribution and influence of this invader are poorly documented. It is also unclear how climate change will affect the expansion of G. quadriradiata. In this study, we built a series of maximum entropy... [Show full abstract]
DOI:10.3969/j.issn.1004-1524.2016.02.19URL [本文引用: 1]
选取撂荒田地为试验样地,以入侵植物豚草(Ambrosia artemisiifolia L.)为对象,以土著优势物种窃衣(Torilis scabra Thunb.)为参照,通过对入侵植物和土著植物根际土壤的采样分析,研究了入侵植物对入侵地土壤特性及土壤碳氮转化的影响.结果表明,与土著物种窃衣相比,豚草入侵使土壤有机质含量增加89.13％,全氮含量增加42.15％,铵态氮含量增加43.69％,硝态氮含量增加35.36％,微生物量碳增加52.08％,微生物量氮增加61.26％,氮净矿化速率增加1.41倍,氮净氢化速率增加2.06倍,但硝化速率和反硝化速率变化不明显.由此可见,豚草显著改变了入侵地土壤的理化特性,加速了土壤碳氮转化过程.
DOI:10.3969/j.issn.1004-1524.2016.02.19URL [本文引用: 1]
选取撂荒田地为试验样地,以入侵植物豚草(Ambrosia artemisiifolia L.)为对象,以土著优势物种窃衣(Torilis scabra Thunb.)为参照,通过对入侵植物和土著植物根际土壤的采样分析,研究了入侵植物对入侵地土壤特性及土壤碳氮转化的影响.结果表明,与土著物种窃衣相比,豚草入侵使土壤有机质含量增加89.13％,全氮含量增加42.15％,铵态氮含量增加43.69％,硝态氮含量增加35.36％,微生物量碳增加52.08％,微生物量氮增加61.26％,氮净矿化速率增加1.41倍,氮净氢化速率增加2.06倍,但硝化速率和反硝化速率变化不明显.由此可见,豚草显著改变了入侵地土壤的理化特性,加速了土壤碳氮转化过程.
DOI:10.1016/j.soilbio.2012.08.018URL [本文引用: 2]
Acacia dealbata Link, an Australian tree legume, is one of the most invasive species in south-eastern Europe. The invasive success of A. dealbata is partially attributed to its ability to release allelopathic compounds that affect native plant species, but the allelopathic effect on soil microbes has been little explored. Here, we used natural leachates to assess the bioactivity of these allelochemicals on soil microorganisms in native Mediterranean pine and mixed forests. Soil samples were treated either with acacia canopyleachate or the corresponding canopy leachate. Soil microbial communities were analyzed using Biolog Ecoplatesi (TM) and PCR-DGGE. Allelochemicals naturally released by A. dealbata clearly modified soil bacterial functional diversity in the pine forest where acacia leachate significantly increased the consumption of carbohydrates and amino acids and reduced the utilization of carboxylic acids. Acacia leachates also lead to a significant reduction in bacterial richness and diversity in the pine forest soil. However, the soil microorganisms of mixed oak forest were insensitive to allelochemical activity. Our results show that the allelopathic effects of A. dealbata on soil microbes depend on ecosystem type and that soil bacteria are more sensitive than soil fungi to the allelochemicals released by A. dealbata. We conclude that the higher sensitivity of pine forest soil microbiota to allelochemicals introduced by A. dealbata can contribute to the process of invasion. (C) 2012 Elsevier Ltd. All rights reserved.
DOI:10.1890/1051-0761(2003)013[0154:EGACOS]2.0.CO;2URL [本文引用: 1]
Exotic invasive grasses and fire have altered plant species composition in the seasonal submontane woodlands of Hawaii Volcanoes National Park. These changes have affected both structural and functional aspects of the plant community, which could have consequences for soil nitrogen (N) dynamics and N availability to plants. To determine if, when, and how soil N dynamics were altered by grass invasion, we measured net and gross N mineralization and nitrification during wet and dry seasons across three vegetation types: (1) experimental grass removal plots within unburned woodland created to simulate the native ecosystem that may have existed prior to invasion; (2) woodland invaded by grasses; and (3) invaded woodland converted to grassland by fire. Grass invasion into woodland shifted the timing, but not the amount, of N available. After conversion to grassland, N-cycling rates were 3.4 times greater. The wet season accounted for 35% of annual net N mineralization in the grass removal treatment, 75% in the grass-invaded woodland, and 90% in the grassland. Soil transplant experiments showed that this shift was caused by an interaction between season and the effects of vegetation type on controls over soil N transformations. The effects of grasses on soil organic matter (SOM) composition enhanced net N mineralization during the wet season, whereas their effects on microclimate depressed net mineralization during the dry season. During the wet season, higher net rates in the grassland were caused by higher rates of gross N mineralization, which were negatively correlated with SOM carbon : N ratio. During the dry season, lower net N mineralization rates in the presence of grasses were due to a larger proportion of gross mineralization being immobilized, which was positively related to soil moisture. These results indicate that changes in plant species composition can alter soil N availability through effects on microclimate as well as more frequently studied effects on SOM composition. Both of these effects appear to have consequences for ecosystem function and should be considered in the design of restoration strategies for ecosystems impacted by exotic plants.
DOI:10.2307/3060923URL [本文引用: 2]
Biological invaders can alter ecosystem processes via multiple pathways, yet few studies have compared the relative importance of these pathways. We assessed the impacts of exotic, invasive grasses on ecosystem nitrogen (N) cycling in the seasonal submontane woodlands of Hawaii Volcanoes National Park, where native grasses have been historically rare. Exotic grasses have become abundant over the past 30 yr and have altered two controls over N cycling: plant species composition and fire regime. Here we synthesize the results of a long-term investigation of species impacts in this system. To determine effects of grasses and fire on internal N cycling, we compared litterfall, decomposition, N mineralization from soil organic matter (SOM), and plant N uptake and production in invaded unburned forest, grass-removal plots within the forest, and woodland converted to grassland by fire. We measured ecosystem N loss via fire by comparing N pools among unburned, naturally burned, and experimentally burned sites. We also assessed the effects of fire on annual N fixation in the unburned forest vs. the grassland. Exotic grasses had relatively small effects on N cycling in the unburned woodland despite being abundant in the understory for 30 yr. Grasses contributed ~30% of fine litterfall and primary-production mass and N in the unburned woodland. However, these contributions did not result in significantly increased totals because litterfall and production of Metrosideros polymorpha, the dominant native tree, was reduced in the invaded woodland relative to grass-removal plots, presumably due to competition with grasses. Although area-weighted decomposition was lower in the grass-removal treatment than in the control, net N mineralization from litter and SOM were similar between these treatments. Annual plant N uptake was similar to annual net N mineralization from SOM in both treatments. By contrast, the burned grassland exhibited much lower rates of litterfall and production mass and N, but higher rates of net N mineralization from SOM than the woodland. As a result, total annual plant N uptake was only 17% of annual net mineralization. This change was primarily due to the loss of native species. Aboveground N pools were significantly reduced with fire. Native species were largely eliminated by fire. However, across all burned and unburned sites there was no change in total ecosystem N because the N contained in biomass was relatively small compared to N in litter and soil. Soil contained >95% of ecosystem N in all sites. Only in the high-intensity experimental burn was there significant loss of N from the soil pool. Fire reduced N inputs through asymbiotic N fixation mainly due to the loss of M. polymorpha, whose litter is an important site of asymbiotic N fixation, and alteration of the soil O-layer. This reduction in N inputs makes it unlikely that fixation activity will replace N lost via combustion before the next fire. Fire and the ensuing loss of native species led to decreased N inputs, increased rates of N mineralization from litter and SOM, and dramatically reduced plant N uptake, potentially leading to a more leaky N cycle. It appears that the indirect effects of grasses on N cycling via the elimination of native species by fire is the most important pathway though which exotic grasses alter ecosystem N dynamics in this system.
DOI:10.1007/BF00328732URLPMID:28307102 [本文引用: 2]
Invasions by exotic weedy plants frequently occur in highly disturbed or otherwise anthropogenically altered habitats. Here we present evidence that, within California coastal prairie, invasion also can be facilitated by a native nitrogen-fixing shrub, bush lupine (Lupinus arboreus). Bush lupines fix nitrogen and grow rapidly, fertilizing the sandy soil with nitrogen-rich litter. The dense lupine canopy blocks light, restricting vegetative growth under bushes. Heavy insect herbivory kills lupines, opening exposed nitrogen-rich sites within the plant community. Eventual re-establishment of lupine occurs because of an abundant and long-lived seed bank. Lupine germination, rapid growth, shading and fertilization of sites, and then death after only a few years, results in a mosaic of nutrient-rich sites that are available to invading species. To determine the role of bush lupine death and nitrogen enrichment in community composition, we examined nutrient dynamics and plant community characteristics within a site only recently colonized by lupine, comparing patches where lupines had recently died or were experimentally killed with adjacent areas lacking lupine. In experimentally killed patches, instantaneous pool sizes of exchangeable ammonium and nitrate nitrogen were higher than in adjacent sites free of lupine. Seedlings of the introduced grass Bromus diandrus accumulated 48% greater root biomass and 93% more shoot biomass when grown in a greenhouse in soil collected under experimentally killed lupines compared to B. diandrus seedlings grown in soil collected at least 1 m away from lupines. At the end of the spring growing season, total above-ground live plant biomass was more than twice as great in dead lupine patches as in the adjacent lupine-free grassland, but dead lupine patches contained 47% fewer plant species and 57% fewer native species. Sites where lupines have repeatedly died and reestablished during recent decades support an interstitial grassland community high in productivity but low in diversity, composed of mostly weedy introduced annual plants. In contrast, at a site only recently colonized by bush lupines, the interstitial grassland consists of a less productive but more diverse set of native and introduced species. We suggest that repeated bouts of lupine germination, establishment, and death can convert a rich native plant community into a less diverse collection of introduced weeds.
DOI:10.1111/1365-2745.12584URL [本文引用: 5]
Summary Exotic plant invasion is often associated with dramatic increases in above-ground net primary productivity and soil nitrogen. However, most evidence for these increases comes from correlative studies of single species, leaving open the question of whether invasive plants drive these processes and whether they are consistent among invaders. We combined field surveys and measurements within experimental plantings to examine how plant productivity, soil nitrogen and the abundance of ammonia-oxidizing bacteria (AOB) change in response to invasions by four exotic species. The relationship between plant productivity and soil nitrate differed among native and invasive species, suggesting a fundamental disparity in the effects of natives and invaders on ecosystem processes. In field surveys, dense patches of all invasive species had higher abundances of AOB than native-dominated sites. Three of the four invasive species had higher productivity, soil nitrate concentrations and rates of potential nitrification as compared to nearby native-dominated communities. In our experimental plantings, we found that two invasive species drove increases in soil nitrate and one invader caused increased productivity after a single season. Synthesis . Our results highlight the importance of the N cycling soil microbial community in how exotic invasive plants alter ecosystem function and show that shifts in function can occur rapidly.
DOI:10.1371/journal.pone.0031596URLPMID:3281088 [本文引用: 1]
Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener.
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DOI:10.1111/1462-2920.12081URLPMID:23360621 [本文引用: 1]
SummaryArbuscular mycorrhizal fungi (AMF) perform an important ecosystem service by improving plant nutrient capture from soil, yet little is known about how AMF influence soil microbial communities during nutrient uptake. We tested whether an AMF modifies the soil microbial community and nitrogen cycling during litter decomposition. A two-chamber microcosm system was employed to create a root-free soil environment to control AMF access to 13C- and 15N-labelled root litter. Using a 16S rRNA gene microarray, we documented that approximately 10% of the bacterial community responded to the AMF, Glomus hoi. Taxa from the Firmicutes responded positively to AMF, while taxa from the Actinobacteria and Comamonadaceae responded negatively to AMF. Phylogenetic analyses indicate that AMF may influence bacterial community assembly processes. Using nanometre-scale secondary ion mass spectrometry (NanoSIMS) we visualized the location of AMF-transported 13C and 15N in plant roots. Bulk isotope ratio mass spectrometry revealed that the AMF exported 4.9% of the litter 15N to the host plant (Plantago lanceolata .), and litter-derived 15N was preferentially exported relative to litter-derived 13C. Our results suggest that the AMF primarily took up N in the inorganic form, and N export is one mechanism by which AMF could modify the soil microbial community and decomposition processes.
DOI:10.2307/1942501URL [本文引用: 1]
Carbon and nitrogen dynamics were analyzed during the decomposition of litter and roots of the desert ephemeral pepperweed (Lepidium lasiocarpum). We treated litter bags with the insecticide chlordane and the fungicides benomyl and captan to eliminate or restrict groups of soil biota. The mass losses of buried litter (51, 39, and 25% for untreated, insecticide-treated, and fungicide-insecticide-treated material, respectively) were higher than those of the respective root treatments (35, 18, and 15%) at 96 d. The mass loss of untreated material was correlated with numbers of detritivorous-fungivorous microarthropods, and only a small percentage of this loss was as CO"2: 27 and 42% for litter and roots, respectively. In the absence of microarthropods a higher percentage of mass-loss carbon could be accounted for as CO"2: 33 and 76% for litter and roots, respectively, indicating that mass loss was due primarily to litter removal by microarthropod activity and not to mineralization. Litter removal by microarthropods was less dependent on abiotic constraints such as soil moisture (r = 0.65, P < .001) than was mass loss when microarthropods were absent (r = 0.79, P < .001). In the absence of microarthropods, mass loss was more closely coupled with biomass of grazers, such as nematodes, which require free water for activity (r = 0.99, P < .0001). Unlike mass loss, carbon mineralization was highest in untreated roots, suggesting a stimulation of microbial activity by microarthropods, while in untreated litter no stimulation was observed when compared to insecticide treatments. This difference was primarily a function of fungivorous microarthropod density, with overgrazing occurring in the untreated litter. Nitrogen budgets indicated the importance of microarthropods in the turnover of root nitrogen. In the presence of microarthropods 132% of the initial root nitrogen could be accounted for after 96 d, while in the absence of microarthropods 270% could be accounted for. This net immobilization of nitrogen was primarily in the soil organic fraction around the roots and was associated with fungal development. Data from this study re-emphasize the importance of microarthropods as regulators of decomposition in deserts and suggest that predation by nematodes or protozoa on bacteria and fungi contributes to rate regulation. Nitrogen flux data suggest that when spring ephemeral plant production is high, decomposition of ephemeral roots with attendant nitrogen immobilization can reduce the nitrogen available to creosotebush, Larrea tridentata, thus reducing shrub production. Higher taxa of soil biota, i.e., nematodes and microarthropods, may thus be important regulators of nitrogen fluxes and of mass loss in decomposition.
DOI:10.1007/s11258-018-0816-4URL [本文引用: 1]
Non-native plants often dominate novel habitats where they did not co-evolve with the local species. The novel weapons hypothesissuggests that non-native plants bring competitive traits against...
DOI:10.1007/s11258-014-0431-yURL [本文引用: 2]
Invasive plants have variable effects on net nitrogen cycling, but how invasion alters gross N cycling is poorly understood. We examine how Bromus inermis (smooth brome) invasion affects gross N cycling rates and investigate potential mechanisms for the changes including relationships between smooth brome and ammonia-oxidizing bacteria (AOB) and archaea (AOA), plant community productivity, and litter quality. Gross nitrogen cycling rates, AOA and AOB population sizes, and plant community productivity were examined in native and invaded plots in smooth brome-invaded rough fescue grassland in central Saskatchewan, Canada. Despite no changes in inorganic nitrogen between invaded and native grassland soils, gross nitrogen mineralization rates and total soil nitrogen were higher in invaded soils. Invaded areas had greater plant productivity and litter production, which likely stimulated microbial activity and higher gross mineralization rates. Nitrification rates did not differ between invaded and native soils. Smooth brome had a weak positive effect on AOA in the B horizon but not in the A horizon, and AOB responded positively in both horizons. These results demonstrate that the full effects of plant invasion on soil N cycling may be masked in net N cycling rate measures.
DOI:10.1111/j.1365-2486.2011.02636.xURLPMID:3597245 [本文引用: 1]
With the growing body of literature assessing the impact of invasive alien plants on resident species and ecosystems, a comprehensive assessment of the relationship between invasive species traits and environmental settings of invasion on the characteristics of impacts is needed. Based on 287 publications with 1551 individual cases that addressed the impact of 167 invasive plant species belonging to 49 families, we present the first global overview of frequencies of significant and non-significant ecological impacts and their directions on 15 outcomes related to the responses of resident populations, species, communities and ecosystems. Species and community outcomes tend to decline following invasions, especially those for plants, but the abundance and richness of the soil biota, as well as concentrations of soil nutrients and water, more often increase than decrease following invasion. Data mining tools revealed that invasive plants exert consistent significant impacts on some outcomes (survival of resident biota, activity of resident animals, resident community productivity, mineral and nutrient content in plant tissues, and fire frequency and intensity), whereas for outcomes at the community level, such as species richness, diversity and soil resources, the significance of impacts is determined by interactions between species traits and the biome invaded. The latter outcomes are most likely to be impacted by annual grasses, and by wind pollinated trees invading mediterranean or tropical biomes. One of the clearest signals in this analysis is that invasive plants are far more likely to cause significant impacts on resident plant and animal richness on islands rather than mainland. This study shows that there is no universal measure of impact and the pattern observed depends on the ecological measure examined. Although impact is strongly context dependent, some species traits, especially life form, stature and pollination syndrome, may provide a means to predict impact, regardless of the particular habitat and geographical region invaded.
DOI:10.1007/s004420000533URLPMID:28547460 [本文引用: 1]
The relative importance of allelopathy and resource competition in plant-plant interactions has been vigorously debated but seldom tested. We used activated carbon to manipulate the effects of root exudates of Centaurea maculosa, a noxious weed in much of western North America, on root elongation rates and growth of the native bunchgrass Festuca idahoensis in order to investigate the relative importance of allelopathy in the total interference of Centaurea. In root observation chambers, Festuca root elongation rates decreased to 50% of the control, beginning 4 days before contacting Centaurea roots in silica sand. However, when activated carbon, which has a high affinity for adsorbing to organic compounds, was added to the sand the effects of Centaurea roots on Festuca root elongation were reduced. In other experiments, Festuca plants were 50% smaller when grown with Centaurea than with conspecifics in pure silica sand. However, Festuca growth with Centaurea in mixtures of sand and activated carbon were 85% larger than Festuca grown with Centaurea in silica sand without carbon. These results suggest that allelopathy accounts for a substantial proportion of the total interference of Centaurea on Festuca, shifting the balance of competition in favor of Centaurea. However, Centaurea outperformed Festuca even in the presence of activated carbon, demonstrating the importance of the combined roles of resource competition and allelopathy.
DOI:10.1007/s00442-008-1089-8URLPMID:18612654 [本文引用: 2]
The invasion of non-native plants can alter the diversity and activity of soil microorganisms and nutrient cycling within forests. We used field studies to analyze the impact of a successful invasive groundcover, Alliaria petiolata, on fungal diversity, soil nutrient availability, and pH in five northeastern US forests. We also used laboratory and greenhouse experiments to test three mechanisms by which A. petiolata may alter soil processes: (1) the release of volatile, cyanogenic glucosides from plant tissue; (2) the exudation of plant secondary compounds from roots; and (3) the decomposition of litter. Fungal community composition was significantly different between invaded and uninvaded soils at one site. Compared to uninvaded plots, plots invaded by A. petiolata were consistently and significantly higher in N, P, Ca and Mg availability, and soil pH. In the laboratory, the release of volatile compounds from the leaves of A. petiolata did not significantly alter soil N availability. Similarly, in the greenhouse, the colonization of native soils by A. petiolata roots did not alter soil nutrient cycling, implying that the exudation of secondary compounds has little effect on soil processes. In a leaf litter decomposition experiment, however, green rosette leaves of A. petiolata significantly increased the rate of decomposition of native tree species. The accelerated decomposition of leaf litter from native trees in the presence of A. petiolata rosette leaves shows that the death of these high-nutrientcontent leaves stimulates decomposition to a greater extent than any negative effect that secondary compounds may have on the activity of the microbes decomposing the native litter. The results presented here, integrated with recent related studies, suggest that this invasive plant may change soil nutrient availability in such a way as to create a positive feedback between site occupancy and continued proliferation.
DOI:10.1007/s10530-008-9280-8URL [本文引用: 2]
The ability to form symbiotic associations with soil microorganisms and the consequences for plant growth were studied for three woody legumes grown in five different soils of a Portuguese coastal dune system. Seedlings of the invasive Acacia02longifolia and the natives Ulex02europaeus and Cytisus02grandiflorus were planted in the five soil types in which at least one of these species appear in the studied coastal dune system. We found significant differences between the three woody legumes in the number of nodules produced, final plant biomass and shoot 15 N content. The number of nodules produced by A.02longifolia was more than five times higher than the number of nodules produced by the native legumes. The obtained 15 N values suggest that both A.02longifolia and U.02europaeus incorporated more biologically-fixed nitrogen than C.02grandiflorus which is also the species with the smallest distribution . Finally, differences were also found between the three species in the allocation of biomass in the different studied soils. Acacia02longifolia displayed a lower phenotypic plasticity than the two native legumes which resulted in a greater allocation to aboveground biomass in the soils with lower nutrient content. We conclude that the invasive success of A.02longifolia in the studied coastal sand dune system is correlated to its capacity to nodulate profusely and to use the biologically-fixed nitrogen to enhance aboveground growth in soils with low N content.
DOI:10.1111/fwb.13073URL [本文引用: 2]
Abstract Wetlands are often biogeochemical hotspots, and they can remove excess N via denitrification and assimilatory uptake. Wetlands are also susceptible to plant invasions, but the effect of invasive plants on denitrification in freshwater wetland sediments is not well-studied. Two distinct mechanisms suggest the potential for invasive plants to alter denitrification. First, invasive plants often produce more biomass than non-invasive species, thus potentially providing additional carbon (C) for denitrifiers. Second, some invasive wetland plants funnel more oxygen into the root zone than non-invasive plants, potentially stimulating coupled nitrification–denitrification. Using the push–pull isotope pairing technique, we measured denitrification and coupled nitrification–denitrification in the sediments beneath monoculture plots of Phragmites australis and Typha domingensis , and beneath unvegetated sediments, in an urban wetland in Melbourne, Australia. We also measured pore water nutrient concentrations and calculated the diffusive flux of nutrients from the sediments into the overlying water column. We hypothesised that plots containing P.australis would have the highest denitrification and coupled nitrification–denitrification rates, followed by plots containing T.domingensis , with the lowest rates in the unvegetated plots, as a result of higher C and oxygen availability. Instead, we found that denitrification and coupled nitrification–denitrification rates were highly variable, with no difference among plot type. However, we did find that diffusive flux of ammonium from the sediments into the water column was lower in the vegetated plots than in the unvegetated plots, suggesting that vegetation enhances wetland N retention via plant assimilatory uptake.
[本文引用: 1]
DOI:10.1007/s10021-004-0009-yURL [本文引用: 1]
We evaluated the effects of the exotic tree Fraxinus uhdei on decomposition dynamics and nutrient turnover in a montane Hawaiian rainforest. We used reciprocal transplants of litterbags between forests dominated by Fraxinus and by the native Metrosideros polymorpha to distinguish between endogenous (litter quality) and exogenous (for example, microclimate, nutrient availability, microbial and invertebrate communities) effects of Fraxinus on mass loss and nutrient dynamics of decomposing litter. Fraxinus produced greater quantities of litter that was thinner, had higher N and P concentrations, and lower concentrations of lignin and soluble polyphenols. Microbes decomposing Fraxinus litter produced fewer enzymes involved in N and P acquisition and more of those involved in cellulose degradation. Differences in litter quality and microbial activity resulted in a strong effect of litter type on rates of mass loss, whereby Fraxinus litter decomposed and released nutrients at nearly twice the rate of Metrosideros litter (k = 0.82 versus 0.48), regardless of site of decomposition. Although site of decomposition had no effect on rates of litter mass loss, Fraxinus litter decomposed under a Fraxinus canopy mineralized approximately 20% less P after one year than Fraxinus litter decomposed under a Metrosideros canopy. Furthermore, Fraxinus litter decomposed under a Fraxinus canopy immobilized greater amounts of N and P in the early stages of decay, suggesting that the large amounts of N and P in Fraxinus litterfall have raised nutrient availability to decomposers in the forest floor. Greater immobilization of N and P under a Fraxinus canopy may act as a governor on rates of nutrient cycling, limiting the degree to which Fraxinus invasion accelerates N and P cycling in this system.
DOI:10.1111/j.1365-2435.2008.01389.xURL [本文引用: 1]
1. A number of biodiversity experiments have shown that plant diversity plays a significant role for ecosystem functioning. However, diversity effects on processes involving multi-trophic interactions such as litter decomposition are rather rare. In these experiments, plant diversity is usually categorized into taxonomic units or functional groups. Continuous measures of functional diversity that are based on measurable traits, in contrast, may be a more flexible way to analyse the functional significance of biodiversity. 2. Litter decomposition is a key process in ecosystem biogeochemistry. To understand the consequences of altered biodiversity for ecosystem functioning, it is thus crucial to quantify any potential diversity effects on decomposition processes. 3. I performed several complementary decomposition trials within the BIODiversity and Ecological Processes in Terrestrial Herbaceous ecosystems (BIODEPTH) experiment, which established a gradient of plant species richness and number of functional groups. I hypothesized that decomposition rates increase with increasing plant diversity due to non-additive litter mixing effects and more favourable microenvironmental conditions. 4. Decomposition rates of both standard materials and community-specific litter increased with the number of functional groups and with a continuous measure of functional diversity. Species richness, in contrast, had no or rather small positive effects on decomposition. Presence of nitrogen-fixing legumes strongly enhanced decomposition, via effects on both litter quality and on the decomposition microenvironment. 5. The predominance of functional diversity rather than of species richness effects suggests that profound knowledge on functional attributes of plant species is the key to understand and to predict biodiversity decomposition relationships.
DOI:10.1016/j.soilbio.2015.07.017URL [本文引用: 3]
61Microstegium vimineum increases the abundance of ammonia-oxidizing archaea.61M. vimineum alters the community composition of ammonia oxidizers.61M. vimineum's impacts are seasonal, and have strong annual variation.61These impacts gradually declined when M. vimineum naturally declined at a site.61These impacts are therefore not likely to result in soil legacies.
DOI:10.1016/j.apsoil.2009.03.002URL [本文引用: 1]
Invasive species can alter the soil nutrient pools and processes in ecosystems that they invade by altering the quality and quantity of litter inputs. Studies have shown the impact of vegetative understory invasions on soil nitrogen (N) availability in forest ecosystems. In the dry deciduous Vindhyan forest of India we studied the effect of one of the world's most noxious weeds, lantana ( Lantana camara L.) on soil N availability and N-mineralization beneath the forest canopy and lantana canopy. We observed that the lantana litter inputs increase with increasing lantana cover and the chemical composition of lantana litter was also very much different from the native forest species litter. High N, low lignin content of the lantana litter and favorable microclimate beneath lantana canopy favored faster decomposition and release of N. This alteration in litter inputs and chemistry beneath the lantana canopy positively and significantly altered soil N availability, N-mineralization, and total soil N. The results imply that a positive feed back nutrient cycle might exist beneath the lantana canopy which may favor its growth (cover) by increasing the nutrients beneath its canopy.
DOI:10.3969/j.issn.1000-6850.2007.04.075URL [本文引用: 1]
以外来入侵杂草加拿大一枝黄花和土著种一枝黄花为研究材料,检测了这两种植物的根部土壤中微生物区系和微生物生理类群的变化。结果表明,具化感作用潜力的加拿大一枝黄花明显影响了土壤中根部微生物群落多样性。具体表现在加拿大一枝黄花根部土壤中的真菌数量低于对照土,而细菌和放线菌的数量则有增多。土著种一枝黄花对根部土壤中微生物的生长均为抑制效应。进一步分析显示,加拿大一枝黄花的根系分泌物对土壤的亚硝酸细菌、好气性自生固氮菌、硫化细菌、氨化细菌和好气性纤维素分解菌的数量具有促进作用,而对反硝化细菌、嫌气性纤维素分解菌和反硫化细菌的生长有抑制效应。据此,文中还探讨了影响外来入侵植物扩散力的生态机制。
DOI:10.3969/j.issn.1000-6850.2007.04.075URL [本文引用: 1]
以外来入侵杂草加拿大一枝黄花和土著种一枝黄花为研究材料,检测了这两种植物的根部土壤中微生物区系和微生物生理类群的变化。结果表明,具化感作用潜力的加拿大一枝黄花明显影响了土壤中根部微生物群落多样性。具体表现在加拿大一枝黄花根部土壤中的真菌数量低于对照土,而细菌和放线菌的数量则有增多。土著种一枝黄花对根部土壤中微生物的生长均为抑制效应。进一步分析显示,加拿大一枝黄花的根系分泌物对土壤的亚硝酸细菌、好气性自生固氮菌、硫化细菌、氨化细菌和好气性纤维素分解菌的数量具有促进作用,而对反硝化细菌、嫌气性纤维素分解菌和反硫化细菌的生长有抑制效应。据此,文中还探讨了影响外来入侵植物扩散力的生态机制。
DOI:10.20417/nzjecolURL [本文引用: 1]
DOI:10.1093/jxb/erq220URLPMID:20627901 [本文引用: 1]
More intense, more frequent, and longer heat waves are expected in the future due to global warming, which could have dramatic ecological impacts. However, few studies have involved invasive species. The aims of this study were to examine the effect of extreme heating (40/35 degrees C for 30 d) on the growth and photosynthesis of an alien invasive species Wedelia trilobata and its indigenous congener (Wedelia chinensis) in South China, and to determine the development of this invasive species and its potential adaptive mechanism. In comparison with W. chinensis, W. trilobata suffered less inhibition of the relative growth rate (RGR) and biomass production due to high temperature, which was consistent with the changes of photosystem II (PSII) activity and net photosynthetic rate (P(n)). High temperature caused a partial inhibition of PSII, but the adverse effect was more severe in W. chinensis. Measurement of the minimum fluorescence (F(o)) versus temperature curves showed that W. trilobata had a higher inflexion temperature of F(o) (T(i)), indicating greater thermostability of the photosynthetic apparatus. Moreover, comparisons of absorbed light energy partitioning revealed that W. trilobata increased xanthophyll-dependent thermal dissipation (Phi(NPQ)) under high temperature, while retaining the higher fraction of absorbed light allocated to photochemistry (Phi(PSII)) relative to W. chinensis. The results suggest that the invasive W. trilobata has a high thermostability of its photosynthetic apparatus and an effective regulating mechanism in energy partitioning of PSII complexes to minimize potential damage and to retain greater capability for carbon assimilation. These factors confer greater heat stress tolerance compared with the native species. Therefore, the invasive W. trilobata may become more aggressive with the increasingly extreme heat climates.
DOI:10.1007/s10530-009-9541-1URL [本文引用: 1]
Increasing atmospheric CO2 concentration is regarded as an important factor facilitating plants invasions by stimulating invasive species growth. However, the physiological mechanisms by which invasive plants increase at the expense of existing native plants are poorly understood. Plant growth is always related to energy-use process including energy assimilation and expenditure, and thus examination of energetic properties could provide mechanistic insight into growth responses to increased CO2. The aims of this study were to examine the effect of rising CO2 on the growth and energetic properties of alien invasive species (Wedelia trilobata (L.) Hitchc.) and its native congener (Wedelia chinensis (Osbeck.) Merr.) in South China, and to determine if the specific energetic properties of invasive species at elevated CO2 favoring its growth. Elevated CO2 stimulated a greater increase in biomass production for invasive W. trilobata (58.9%) than for its indigenous congener (48.1%). Meanwhile, elevated CO2 altered the energetic properties differently upon species. For invasive W. trilobata, elevated CO2 significantly increased total energetic gain via photosynthetic activity (A (total)), but decreased energetic cost of biomass construction (CC), and thus enhanced photosynthetic energy-use efficiency (PEUE) by 85.3%. In contrast, the indigenous W. chinensis showed a slight increase in PEUE by 43.8%. Additionally, W. trilobata individuals grown in elevated CO2 increased energy allocation towards stems. Statistic analysis revealed significant associations between growth characteristics (relative growth rate and biomass) and energetic properties (CC and PEUE), suggesting the greater growth stimulation in invasive species could be partly explained by its specific energetic properties in elevated CO2 concentration. The invasive species showed a greater increase in energy-use efficiency under elevated CO2, which consequently facilitated its growth. It might be a physiological mechanism promoting success of invasion with ongoing increase in atmospheric CO2 concentration.
DOI:10.1023/A:1005504029243URL [本文引用: 2]
Plant-produced phenolic compounds inhibit soil microbial activity and are suspected to be involved in the failure of natural regeneration of French subalpine Norway spruce ( Picea abies ) forests. This work evaluated relationships between phenolic compounds and soil microorganisms in humus collected in spruce forest during winter and summer seasons. After having identified and quantified different phenolics from humus samples, we incubated another set of humus samples with 10 times the concentration of naturally occurring phenolics, and effects on the density of microorganisms were compared to humus with no addition of phenolic compounds. Furthermore, in order to follow the degradation of phenolic compounds by microbes, the concentration of phenolics in the incubated humus samples was determined by HPLC after three and six days of incubation. The results indicate that humus microorganisms use phenolics as a carbon source, since almost all phenolic compounds had disappeared after six days of incubation. Addition of phenolic compounds to the humus samples also affected the soil microbial populations so that bacteria were inhibited in the humus collected both in the winter and in the summer. However, there were differences between the experiments. Fungi and cellulose hydrolyzers were stimulated in the winter humus experiment, while fungi were unaffected and cellulose hydrolyzers were inhibited in the summer experiment. The addition of phenolic compounds stimulated ammonifiers in the summer experiment. We anticipate that the role of soil microorganisms in the problem of natural regeneration failure is probably more important than previously thought.
DOI:10.1016/j.soilbio.2014.09.008URL [本文引用: 1]
61Soil biochemical parameters were deeply altered under Acacia dealbata invasion.61Decomposition processes could be accelerated in the presence of A.02dealbata.61Microbial community activity was generally increased in invaded soils.61Biochemical and microbial changes were more noticeable in the shrubland.61Phenological stage did not significantly affect soil microbial activity.
DOI:10.1007/s00442-014-3093-5URLPMID:25304974 [本文引用: 1]
Previous studies comparing invaded and non-invaded sites suggest that cheatgrass ( Bromus tectorum L.) causes soil N cycling to increase. Unfortunately, these correlative studies fail to distinguish whether cheatgrass caused the differences in N cycling, or if cheatgrass simply invaded sites where N availability was greater. We measured soil C and N concentrations and net and gross N-cycling rates on 24-year-old replicated field plots in a sagebrush–steppe ecosystem that had been plowed, fumigated, and seeded to different plant communities in 1984. Laboratory assays of soil collected throughout the soil profiles (0–6002cm) showed that soil NO 3 61 , organic C and N, and net N mineralization, net nitrification, and soil respiration rates were all greater beneath cheatgrass than in sagebrush–perennial grass plots. In surface soils (0–1002cm), field and lab assays on five sampling dates during 202years showed gross N mineralization, net N mineralization, and net nitrification rates were all faster beneath cheatgrass than in sagebrush–perennial grass plots. Modeling analyses based on soil respiration and gross N-cycling rates suggest that cheatgrass provides soil microbes with lower C:N substrates and that this could explain the faster N-cycling rates beneath cheatgrass. This is the first long-term replicated field study to conclusively show that cheatgrass created greater soil organic N pool sizes and stimulated N-cycling rates compared to similar-aged stands of sagebrush and native perennial grasses. Increased N-cycling rates may represent a positive plant–soil feedback that promotes continued dominance by cheatgrass, even in the absence of soil disturbance or fire.
DOI:10.2307/1938416URL [本文引用: 1]
DOI:10.1016/j.soilbio.2012.09.016URL [本文引用: 1]
One cascading feature of the spread of introduced species of plants is their capacity to alter levels of resource availabilities for other species. However, the effects of introduced species on temporal patterns of soil nutrient availability remain unexplored, which could be critical for invasion where the growing seasons are short. To test the hypothesis that the invasive species could alter seasonal patterns of resource availability via suppression of soil processes through secondary compounds in autumnal litter-fall, we measured nutrient dynamics in soils inside and outside stands of invasive Polygonum cuspidatum at four sites in northeastern US over the growing season. In the uppermost soil (0–502cm depth), both concentrations of inorganic N and rates of N mineralization were 60% lower inside than outside stands of knotweed in spring but became as high or higher inside than outside by fall. Carbon and nitrogen mineralizing soil microbial enzymes also followed a similar seasonal trend with lower activity inside the knotweed stands than outside during spring and these differences disappearing by summer. Concentrations of dissolved organic N (DON) and phenolic compounds showed the opposite seasonal pattern and a strong correlational trend; they were nearly 3 times higher inside than outside stands in spring and similar inside and outside in fall. The estimated flux of tannins from knotweed litter to soil was calculated as 189.502±0239.202g02m61202year611. Further, exogenous application of knotweed tannin reduced the soil N-mineralization and paralleled the field observed inhibition of mineralization. At 5–1502cm depth, concentrations of phenolics were uniformly low and differences between soils inside and outside stands were mostly non-significant. Our results suggests that invasion by polyphenol rich, yet fast growing exotic species would make the soil N pools more dynamic, which could facilitate invasion by creating stints of apparent deficiency and sufficiency of resources, and due to the localization of the invader effect the amelioration practices could be focused on the surface 0–502cm layer of the mineral soil.
DOI:10.1007/s10530-010-9902-9URL [本文引用: 2]
The success of some invasive plants may be due in part to native organisms lacking adaptation to species-specific biochemical traits of invaders-the Novel Weapons Hypothesis. We tested this hypothesis in the context of soil microbial communities by comparing the effects of Centaurea stoebe and the root exudate (+/-)-catechin, on ammonification and nitrification in both the non-native and native ranges of this species. In a non-native range (Montana), soil nitrate (NO3 (-)) concentrations were lower in invaded than uninvaded grasslands. This did not appear to be due only to higher uptake rates as both C. stoebe plants and catechin significantly reduced resin extractable NO3 (-), the maximum rate of nitrification, and gross nitrification in Montana soils. Thus, reduced NO3 (-) in invaded communities may be due in part to the inhibition of nitrifying bacteria by secondary metabolites produced by C. stoebe. The effects of C. stoebe on N-related processes were different in Romanian grasslands, where C. stoebe is native. In Romanian soil, C. stoebe had no effect on resin extractable NH4 (+) or NO3 (-) (compared to other plant species), the maximum rate of nitrification, nor gross nitrification. A relatively high concentration of catechin reduced the maximum rate of nitrification in situ, but substantially less than in Montana. In vivo, gross ammonification was lowest when treated with catechin. Our results suggest biogeographic differences in the way a plant species alters nitrogen cycling through the direct effects of root exudates and adds to a growing body of literature demonstrating the important belowground effects of invasive plants.
DOI:10.1111/j.1365-2745.2009.01520.xURL [本文引用: 1]
1. Exotic invasive plants can have strong effects on native communities. Centaurea maculosa , a forb that is native to Eurasia, has created near-monocultures in many parts of its invaded range in western North America and produces the root exudate (±)-catechin. Controlled laboratory experiments suggest that the phytotoxic effects of (±)-catechin may be stronger on some North American species than on some European species.
DOI:10.1111/j.1462-2920.2005.00906.xURLPMID:16309395 [本文引用: 1]
Mesophilic crenarchaeota are frequently found in terrestrial and marine habitats worldwide, but despite their considerable abundance the physiology of these as yet uncultivated archaea has remained unknown. From a 1.2 Gb large-insert environmental fosmid library of a calcareous grassland soil, a 43 kb genomic fragment was isolated with a ribosomal RNA that shows its affiliation to group 1.1b of crenarchaeota repeatedly found in soils. The insert encoded a homologue of a copper-containing nitrite reductase with an unusual C-terminus that encoded a potential amicyanin-like electron transfer domain as well as two proteins related to subunits of ammonia monooxygenases or particulate methane monooxygenases (AmoAB/PmoAB) respectively. Expression of nirK and the amo A-like gene was shown by reverse transcription polymerase chain reaction (PCR) analyses in soil samples, the latter being found at higher levels when the soil was incubated with ammonia (measured by quantitative PCR). Further variants of both genes were amplified from soil samples and were found in the environmental database from the Sargasso Sea plankton. Taken together, our findings suggest that mesophilic terrestrial and marine crenarchaeota might be capable of ammonia oxidation under aerobic and potentially also under anaerobic conditions.
[本文引用: 2]
DOI:10.1038/ismej.2007.9URLPMID:18043611 [本文引用: 1]
Abstract Invasive microbes, plants and animals are a major threat to the composition and functioning of ecosystems; however, the mechanistic basis of why exotic species can be so abundant and disruptive is not well understood. Most studies have focused on invasive plants and animals, although few have considered the effects of invasive microbes, or interactions of invasive plant and animal species with microbial communities. Here, we review effects of invasive plants on soil microbial communities and discuss consequences for plant performance, plant community structure and ecosystem processes. In addition, we briefly discuss effects of invasive soil microbes on plant communities, which has been less well studied, and effects of invasive animals on soil decomposers and ecosystem functioning. We do this by considering each of three important functional groups of microbes, namely soil microbial parasites and pathogens, mutualistic symbionts and decomposers. We conclude that invasive plants, pathogenic and symbiotic soil microbes will have strongest effects on the abundance of individual species, community diversity and ecosystem functioning. Invasive decomposer microbes probably have little impact, because of limited specificity and great functional redundancy. However, invasive plants and animals can have major effects on microbial decomposition in soil. We propose that understanding, predicting and counteracting consequences of enhanced global homogenization of natural communities through introducing exotic plants, animals and microbes will require future studies on how pathogenic, symbiotic and decomposer soil microbes interact, how they are influenced by higher trophic level organisms and how their combined effects are influencing the composition and functioning of ecosystems.
DOI:10.1126/science.1093857URL [本文引用: 1]
We have applied ``whole-genome shotgun sequencing'' to microbial populations collected en masse on tangential flow and impact filters from seawater samples collected from the Sargasso Sea near Bermuda. A total of 1.045 billion base pairs of nonredundant sequence was generated, annotated, and analyzed to elucidate the gene content, diversity, and relative abundance of the organisms within these environmental samples. These data are estimated to derive from at least 1800 genomic species based on sequence relatedness, including 148 previously unknown bacterial phylotypes. We have identified over 1.2 million previously unknown genes represented in these samples, including more than 782 new rhodopsin-like photoreceptors. Variation in species present and stoichiometry suggests substantial oceanic microbial diversity.
DOI:10.1016/j.soilbio.2011.11.018URL [本文引用: 2]
Nitrogen is a major nutrient that frequently limits primary productivity in terrestrial ecosystems. Therefore, the physiological responses of plants to soil nitrogen (N) availability have been extensively investigated, and the study of the soil N-cycle has become an important component of ecosystem ecology and biogeochemistry. The bulk of the literature in these areas has, however, overlooked the fact that most plants form mycorrhizal associations, and that nutrient uptake is therefore mediated by mycorrhizal fungi. It is well established that ecto- and ericoid mycorrhizas influence N nutrition of plants, but roles of arbuscular mycorrhizas in N nutrition are less well established; perhaps even more importantly, current conceptual models ignore possible influences of arbuscular mycorrhizal (AM) fungi on N-cycling processes. We review evidence for the interaction between the AM symbiosis with microbes and processes involved in soil N-cycling. We show that to date investigations have rather poorly addressed such interactions and discuss possible reasons for this. We outline mechanisms that could potentially operate with regards to AM fungal N-cycling interactions, discuss experimental designs aimed at studying these, and conclude by pointing out priorities for future research.
DOI:10.1016/j.soilbio.2012.05.007URL [本文引用: 1]
Impacts of divergent arbuscular mycorrhizal (AM) fungi, Glomus intraradices and Gigaspora margarita, on denitrifying and diazotrophic bacterial communities of Plantago lanceolata in nutrient-limited dune soil were assessed. We hypothesized AM species-related modifications that were confirmed in respective bacterial nirK and nifH sequence polymorphism -based community clustering and community variance allocation. The denitrifying community appeared more responsive to AM fungi than the nitrogen-fixing community. Nevertheless, the main explanatory variable, in both cases, was plant age. We conclude that AM fungi can modify N-cycling microbial rhizosphere communities and future work should aim to verify the functional significance and mechanistic basis.
DOI:10.1111/j.1461-0248.2011.01628.xURLPMID:21592274 [本文引用: 1]
Abstract Biological invasions cause ecological and economic impacts across the globe. However, it is unclear whether there are strong patterns in terms of their major effects, how the vulnerability of different ecosystems varies and which ecosystem services are at greatest risk. We present a global meta-analysis of 199 articles reporting 1041 field studies that in total describe the impacts of 135 alien plant taxa on resident species, communities and ecosystems. Across studies, alien plants had a significant effect in 11 of 24 different types of impact assessed. The magnitude and direction of the impact varied both within and between different types of impact. On average, abundance and diversity of the resident species decreased in invaded sites, whereas primary production and several ecosystem processes were enhanced. While alien N-fixing species had greater impacts on N-cycling variables, they did not consistently affect other impact types. The magnitude of the impacts was not significantly different between island and mainland ecosystems. Overall, alien species impacts are heterogeneous and not unidirectional even within particular impact types. Our analysis also reveals that by the time changes in nutrient cycling are detected, major impacts on plant species and communities are likely to have already occurred. 2011 Blackwell Publishing Ltd/CNRS.
DOI:10.1111/j.1461-0248.2004.00576.xURL [本文引用: 1]
Centaurea diffusa is one of the most destructive invasive weeds in the western USA and allelopathy appears to contribute to its invasiveness (Callaway & Aschehoug 2000). Here we identify a chemical from the root exudates of C. diffusa, 8-hydroxyquinoline, not previously reported as a natural product, and find that it varies biogeographically in its natural concentration and its effect as an allelochemical. 8-Hydroxyquinoline is at least three times more concentrated in C. diffusa-invaded North American soils than in this weed's native Eurasian soils and has stronger phytotoxic effects on grass species from North America than on grass species from Eurasia. Furthermore, experimental communities built from North American plant species are far more susceptible to invasion by C. diffusa than communities built from Eurasian species, regardless of the biogeographical origin of the soil biota. Sterilization of North American soils suppressed C. diffusa more than sterilization of Eurasian soils, indicating that North American soil biota may also promote invasion by C. diffusa. Eurasian plants and soil microbes may have evolved natural resistance to 8-hydroxyquinoline while North American plants have not, suggesting a remarkable potential for evolutionary compatibility and homeostasis among plants within natural communities and a mechanism by which exotic weeds destroy these communities.
In: McMichael BL, Persson H eds.
DOI:10.1016/B978-0-444-89104-4.50028-1URL [本文引用: 1]
The contribution of belowground litter inputs to soil organic matter will be addressed for forest ecosystems. The relative contribution of carbon from above- and belowground tissues to soil organic matter will be contrasted by considering (1) the magnitude of each input, (2) what controls the timing of inputs, (3) the chemical quality of these inputs and (4) their decay rates. Available literature will be synthesized to form some generalities for these four subject areas. In addition, belowground contribution to organic matter accumulation will be compared between deciduous and evergreen tree species.
DOI:10.1016/j.apsoil.2005.02.017URL [本文引用: 1]
Centaurea maculosa, an invasive forb in western North American grasslands, dominates more than 4 million ha of rangeland in the Rocky Mountain region. Our research examined the effects of herbivory and arbuscular mycorrhizae (AM) on the growth of C. maculosa, and two native grasses, Festuca idahoensis and Pseudoroegneria spicata. Plants were grown for 11 weeks, with or without AM, prior to simulated herbivory. We removed 75% of aboveground biomass from half of the plants, and harvested all plants 4 weeks later. All species increased their growth rate after clipping, but clipped plants were smaller than unclipped plants. The difference in biomass between clipped and unclipped plants was smaller for C. maculosa (clipped:unclipped = 0.62) than for the native grasses (0.42 and 0.52). Plants with AM were smaller than non-AM plants across all species, with the greatest reduction in F. idahoensis (77% versus 18% in C. maculosa and P. spicata). Levels of AM colonization were minimal in F. idahoensis (<1% of root length colonized), intermediate in P. spicata (13% colonization) and highest in C. maculosa (20%). Extra radical hyphae (ERH) lengths were highest for C. maculosa, and equal between the two grasses. Because of the lower biomass, plant tissue N concentrations were higher in AM plants, but P concentrations increased in AM plants for only C. maculosa and P. spicata. The superior competitive ability of C. maculosa may be the result of greater compensatory growth after herbivory and higher amounts of ERH, both of which result in greater resource capture.
DOI:10.3724/SP.J.1011.2011.00130URL [本文引用: 1]
中国科学院机构知识库(CAS IR GRID)以发展机构知识能力和知识管理能力为目标，快速实现对本机构知识资产的收集、长期保存、合理传播利用，积极建设对知识内容进行捕获、转化、传播、利用和审计的能力，逐步建设包括知识内容分析、关系分析和能力审计在内的知识服务能力，开展综合知识管理。
DOI:10.3724/SP.J.1011.2011.00130URL [本文引用: 1]
中国科学院机构知识库(CAS IR GRID)以发展机构知识能力和知识管理能力为目标，快速实现对本机构知识资产的收集、长期保存、合理传播利用，积极建设对知识内容进行捕获、转化、传播、利用和审计的能力，逐步建设包括知识内容分析、关系分析和能力审计在内的知识服务能力，开展综合知识管理。
DOI:10.4236/ajps.2015.61005URL [本文引用: 1]
The increasing degree of plant invasion is an expanding problem that affects the functioning and composition of forest ecosystems with increasing anthropogenic activities, particularly soil nitrogen (N) cycles. Numerous studies have revealed that one of the main factors for successful plant invasion is that plants could pose significant effects on soil N cycles via direct and/or indirect ways, such as changes in soil microbial communities, litter decomposition rates, and/or soil physicochemical properties. We thereby summarize the ecological effects of invasive plants on soil N cycles, including the aforementioned changes, to understand the mechanism of successful invasion. We also discuss the needs for further research on the relationship between invasive plants and soil N cycles.
DOI:10.1007/s11368-015-1074-xURL [本文引用: 1]
Purpose The aim of this study was to elucidate the impact of plant on the activity, abundance, and the community composition of the ammonia oxidizers, including both ammonia-oxidizing archaea (AOA)...
DOI:10.1007/s10886-010-9843-xURLPMID:20821346 [本文引用: 1]
To better understand the effect of predicted elevated levels of carbon dioxide (CO60) on an invasive weed Mikania micrantha, we constructed a suppressive subtractive hybridization (SSH) library from the leaves of M. micrantha exposed to CO60 at 350 and 750 ppm for 6 d, and isolated a novel gene named β-caryophyllene synthase. β-Caryophyllene synthase catalyses the conversion of farnesyl diphosphate to β-caryophyllene, a volatile sesquiterpene with allelopathic potential. Real-time PCR analysis revealed that gene expression of β-caryophyllene synthase in M. micrantha leaves was strongly induced in response to elevated CO60. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography (GC) analyses showed that emission levels of β-caryophyllene from leaves of M. micrantha increased when exposed to 750 ppm CO60. Bioassays showed that phytotoxicity of β-caryophyllene against Raphanus sativus, Brassica campestris, Lactuca sativa, and M. micrantha was dose-dependent and varied with the receptor plants and concentrations of CO60. β-Caryophyllene displayed higher phytotoxic effects at 750 ppm than those at 350 ppm CO60, especially on R. sativus. These results suggest that elevated atmospheric CO60 levels may enhance biosynthesis and phytotoxicity of allelochemicals in M. micrantha, one of the worst invasive weeds in the world, which in turn might enhance its potential allelopathic effect on neighboring native plants if released in bioactive concentrations. Further investigations are required to determine the adaptive responses of both invasive and native plants to a gradual increase of atmospheric CO60 to 750 ppm predicted over a 100 year period.
[本文引用: 1]
DOI:10.1016/j.soilbio.2008.12.019URL [本文引用: 2]
Invasive plant species have been shown to alter the microbial community composition of the soils they invade and it is suggested that this below-ground perturbation of potential pathogens, decomposers or symbionts may feedback positively to allow invasive success. Whether these perturbations are mediated through specific components of root exudation are not understood. We focussed on 8-hydroxyquinoline, a putative allelochemical of Centaurea diffusa (diffuse knapweed) and used an artificial root system to differentiate the effects of 8-hydroxyquinoline against a background of total rhizodeposition as mimicked through supply of a synthetic exudate solution. In soil proximal (0-10 cm) to the artificial root, synthetic exudates had a highly significant (P < 0.001) influence on dehydrogenase, fluorescein diacetate hydrolysis and urease activity. in addition, 8-hydroxyquinoline was significant (p = 0.003) as a main effect on dehydrogenase activity and interacted with synthetic exudates to affect urease activity (p = 0.09). Hierarchical cluster analysis of 16S rDNA-based DGGE band patterns also identified a primary affect of synthetic exudates and a secondary affect of 8-hydroxyquinoline on bacterial community structure. Thus, we show that the artificial rhizosphere produced by the synthetic exudates was the predominant effect, but, that the influence of the 8-hydroxyquinoline signal on the activity and structure of soil microbial communities could also be detected. (C) 2009 Elsevier Ltd. All rights reserved.
DOI:10.1890/02-5005URL [本文引用: 2]
Using comparative analysis of the rates of key processes, we have documented the net effect of a shift in plant species composition on nitrogen cycles with the example of the rapid expansion of Phragmites australis (common reed) and its replacement of short grasses (e.g., Spartina patens) in coastal marshes of the eastern United States. In this study, we measured nitrogen (N) uptake by marsh plants, N adsorption from the water column by litter, changes in N content of litter, sediment N mineralization, nitrification, and nitrate consumption in adjacent plots dominated either by P. australis or by historically dominant S. patens. Rates of individual processes were generally greater in P. australis than in S. patens, but the magnitude of difference varied greatly among processes. Seasonal measurements of standing stock nitrogen in plant tissue indicate that P. australis took up ~60% more N than did S. patens, and annual fates of N immobilization were nearly 300% greater in P. australis litter than in S. patens litter. The greater demand for N in P. australis plots, however, was apparently compensated for by increased rates of N supply; mineralization rates in P. australis sediments were nearly 300% greater than those in sediments with S. patens. Rates of nitrate reduction (dissimilatory and assimilatory) were 300% greater in P. australis sediments. Whereas P. australis clearly sequestered more N in live and dead biomass than did S. patens, the presence of P. australis also stimulated the microbial production of inorganic N. This compensation of increased N demand with increased N supply suggests that the net nitrogen budget (input-output) of brackish tidal marshes is not immediately altered by the replacement of S. patens with P. australis. However, the greater magnitude of internal N cycling in P. australis communities is likely to influence the mobility of N pools, thereby altering pathways of N export.
[本文引用: 1]
DOI:10.1111/j.1061-2971.2004.00289.xURL [本文引用: 1]
Recent efforts to clear invasive plants from the fynbos of South Africa forces managers to think about how N-fixing invasives have altered ecosystem processes and the implications of these changes for community development. This study investigated the changes in nitrogen (N) cycling regimes in fynbos with the invasion of , the effects of clear-cutting acacia stands on soil microclimate and N cycling, and how altered N resources affected the growth of a weedy grass species. Litterfall, litter quality, soil nutrient pools, and ion exchange resin (IER)-available soil N were measured in uninvaded fynbos, intact acacia, and cleared acacia stands. In addition, a bioassay experiment was used to ascertain whether the changes in soil nutrient availability associated with acacia would enhance the success of a weedy grass species. Acacia plots had greater amounts of litterfall, which had higher concentrations of N. This led to larger quantities of organic matter, total N, and IER-available N in the soil. Clearing acacia stands caused changes in soil moisture and temperature, but did not result in differences in IER-available N. The alteration of N availability by acacias was shown to increase growth rates of the weedy grass , suggesting that secondary invasions by nitrophilous weedy species may occur after clearing N-fixing alien species in the fynbos. It is suggested that managers use controlled burns, the addition of mulch, and the addition of fynbos seed after clearing to lower the levels of available N in the soil and initiate the return of native vegetation.
DOI:10.17521/cjpe.2004.0101URL [本文引用: 1]
在紫茎泽兰(Eupatorium adenophorum)入侵地,草本层中的本地植物的多度和盖度与紫茎泽兰的多度和盖度具有显著的负相关关系,落叶阔叶林和公路边生境的紫茎泽兰相对多度和盖度为常绿阔叶林生境的3～5倍;而本地草本植物在组成种类、相对多度和盖度在落叶阔叶林和公路边生境比常绿阔叶林生境减少了30%、50%和70%.用生物检测的方法研究常绿阔叶林、落叶阔叶林、公路边--3个不同生境下的紫茎泽兰根和茎的水浸提液的化感作用表明:不同生境的紫茎泽兰茎和根的化感作用存在差异,即公路边＞落叶阔叶林下＞常绿阔叶林下,关联分析显示出不同生境条件下的化感作用力与本地植物的相对多度存在显著的相关关系,证明不同生境的化感作用的差异是紫茎泽兰的入侵效果的原因之一;在白菜(Brassica rapa)幼苗生物量生长抑制试验中,各样地的茎提取液处理的白菜幼苗生物量之间的差异大于各样地的根提取液处理之间的差异,说明对于不同样地的紫茎泽兰的入侵力,地上部分的化感作用比地下部分具有更大的贡献力.落叶阔叶林下和公路边的紫茎泽兰生长旺盛、现存单位面积生物量远远高于常绿阔叶林下,这将促使落叶阔叶林和公路边生境的单位面积上的紫茎泽兰种群的化感作用大于常绿阔叶林下的紫茎泽兰种群,使落叶阔叶林和公路边生境的本地植物群落比常绿阔叶林下的本地植物群落面临较大的竞争压力,加速落叶阔叶林下和公路边生境的本地植物群落的衰退.
DOI:10.17521/cjpe.2004.0101URL [本文引用: 1]
在紫茎泽兰(Eupatorium adenophorum)入侵地,草本层中的本地植物的多度和盖度与紫茎泽兰的多度和盖度具有显著的负相关关系,落叶阔叶林和公路边生境的紫茎泽兰相对多度和盖度为常绿阔叶林生境的3～5倍;而本地草本植物在组成种类、相对多度和盖度在落叶阔叶林和公路边生境比常绿阔叶林生境减少了30%、50%和70%.用生物检测的方法研究常绿阔叶林、落叶阔叶林、公路边--3个不同生境下的紫茎泽兰根和茎的水浸提液的化感作用表明:不同生境的紫茎泽兰茎和根的化感作用存在差异,即公路边＞落叶阔叶林下＞常绿阔叶林下,关联分析显示出不同生境条件下的化感作用力与本地植物的相对多度存在显著的相关关系,证明不同生境的化感作用的差异是紫茎泽兰的入侵效果的原因之一;在白菜(Brassica rapa)幼苗生物量生长抑制试验中,各样地的茎提取液处理的白菜幼苗生物量之间的差异大于各样地的根提取液处理之间的差异,说明对于不同样地的紫茎泽兰的入侵力,地上部分的化感作用比地下部分具有更大的贡献力.落叶阔叶林下和公路边的紫茎泽兰生长旺盛、现存单位面积生物量远远高于常绿阔叶林下,这将促使落叶阔叶林和公路边生境的单位面积上的紫茎泽兰种群的化感作用大于常绿阔叶林下的紫茎泽兰种群,使落叶阔叶林和公路边生境的本地植物群落比常绿阔叶林下的本地植物群落面临较大的竞争压力,加速落叶阔叶林下和公路边生境的本地植物群落的衰退.
DOI:10.1007/s11368-011-0369-9URL [本文引用: 2]
Purpose Spartina alterniflora widely invades coastal wetland in China and might change nitrification in sediment. Both ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) are involved in nitrification in this environment. The objective of this study was to examine the effect of S . alterniflora invasion on abundance and composition of AOA and AOB. Materials and methods The abundance and composition of AOA, AOB, and total bacteria in the sediments from S. alterniflora -invaded native mangrove vegetated and unvegetated zones at two depths of 0–502cm (O) and 5–2002cm (R) were investigated using quantitative real-time polymerase chain reaction and denaturing gradient gel electrophoresis. Relationships were also determined between sediment properties and the AOB and AOA population sizes. Results and discussion Compared with native mangrove vegetated zone, the archaeal amoA gene abundance was reduced by 11.3-fold (O) and 46.1-fold (R), but the bacterial amoA gene abundance was increased by 9.8-fold (O) and 1.8-fold (R), respectively, in the S. alterniflora -invaded zone. The AOA abundance was always higher than AOB, especially in the native mangrove zone. Both AOA and AOB population sizes in the upper layer (O) were bigger than those in the deeper layer (R). Little difference was found in the AOB community composition among different zones, while diversity of AOA community was increased by the presence of S. alterniflora. Conclusions This study demonstrated that the S. alterniflora invasion affects the abundance of both AOA and AOB, but only affects the community composition of AOA in the tidal sediments.
[本文引用: 1]
DOI:10.5846/stxb201109201385URL [本文引用: 1]
为了调查崇明东滩湿地入侵植物互花米草(Spartina Alterniflora)在不同潮汐带和季节根际细菌的多样性与丰富度,以本地植物芦苇、海三棱藨草(P.australis和S.mariqueter)和光滩为对照实验研究,在崇明东滩湿地10样点采集根际土壤和光滩土壤,通过PCR-DGGE分子生物学等技术并结合传统培养方法对土壤细菌进行分析研究。研究表明:东滩湿地不同潮汐带的植物根际细菌群落丰富度和多样性不同,在夏季中潮带的根际细菌丰富度(P=0.0210.05)较高,各个潮带的植物根际细菌在夏秋季有高多样性,其中中潮带的植物根际细菌平均多样性指数最高(H=4.20)。在中潮带入侵物种互花米草根际细菌的丰富度和多样性要显著高于本地植物芦苇和海三棱藨草,其中海三棱藨草的根际细菌在夏季略高。崇明东滩湿地入侵植物互花米草根际细菌与本地植物相比较具有较高的多样性,而且外来种互花米草对湿地土壤微生物群落结构有着较强影响;入侵种互花米草根际细菌的高丰富度和多样性可能是其成功入侵东滩湿地的一个重要因素。
DOI:10.5846/stxb201109201385URL [本文引用: 1]
为了调查崇明东滩湿地入侵植物互花米草(Spartina Alterniflora)在不同潮汐带和季节根际细菌的多样性与丰富度,以本地植物芦苇、海三棱藨草(P.australis和S.mariqueter)和光滩为对照实验研究,在崇明东滩湿地10样点采集根际土壤和光滩土壤,通过PCR-DGGE分子生物学等技术并结合传统培养方法对土壤细菌进行分析研究。研究表明:东滩湿地不同潮汐带的植物根际细菌群落丰富度和多样性不同,在夏季中潮带的根际细菌丰富度(P=0.0210.05)较高,各个潮带的植物根际细菌在夏秋季有高多样性,其中中潮带的植物根际细菌平均多样性指数最高(H=4.20)。在中潮带入侵物种互花米草根际细菌的丰富度和多样性要显著高于本地植物芦苇和海三棱藨草,其中海三棱藨草的根际细菌在夏季略高。崇明东滩湿地入侵植物互花米草根际细菌与本地植物相比较具有较高的多样性,而且外来种互花米草对湿地土壤微生物群落结构有着较强影响;入侵种互花米草根际细菌的高丰富度和多样性可能是其成功入侵东滩湿地的一个重要因素。
DOI:10.3969/j.issn.1008-8873.2011.02.020URL [本文引用: 1]
Introduction and invasion of exotic plants are important global issues.Exotic plants can not only change the input and output of nitrogen,but also affect the nitrogen flows within terrestrial ecosystem through altering absorption and reuse of nitrogen,litter quality,soil microcosm and soil biota.Based on terrestrial nitrogen cycling framework,we reviewed the pathways and consequences that exotic plants affect terrestrial nitrogen cycling.Complexity of mechanisms,interaction of different nutrient cycling,and advanced technology should be considered in future research.
DOI:10.3969/j.issn.1008-8873.2011.02.020URL [本文引用: 1]
Introduction and invasion of exotic plants are important global issues.Exotic plants can not only change the input and output of nitrogen,but also affect the nitrogen flows within terrestrial ecosystem through altering absorption and reuse of nitrogen,litter quality,soil microcosm and soil biota.Based on terrestrial nitrogen cycling framework,we reviewed the pathways and consequences that exotic plants affect terrestrial nitrogen cycling.Complexity of mechanisms,interaction of different nutrient cycling,and advanced technology should be considered in future research.
[本文引用: 2]
DOI:10.1007/s00374-016-1127-3URL [本文引用: 1]
We studied the effects of invasions by three plant species: Reynoutria japonica, Rudbeckia laciniata, and Solidago gigantea, on arbuscular mycorrhizal fungi (AMF) communities in habitats located withi
Rapid nutrient cycling in leaf litter from invasive plants in Hawai’i
3
2004
...
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
... ).入侵植物凋落物含N量往往比本地种的高, 含N量高的凋落物分解更快, 所以入侵植物的凋落物分解相对更快(
Effects of an invasive cattail species ( Typha × glauca) on sediment nitrogen and microbial community composition in a freshwater wetland
1
2006
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
入侵植物与丛枝菌根真菌的相互作用
3
2011
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
... 外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应.近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系.与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean.另外, 入侵植物的化感作用也会影响植物与AMF的共生关系,
入侵植物与丛枝菌根真菌的相互作用
3
2011
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
... 外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应.近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系.与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean.另外, 入侵植物的化感作用也会影响植物与AMF的共生关系,
Allelopathy and exotic plant invasion: From molecules and genes to species interactions
3
2003
...
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Inhibitory effects of Eucalyptus globulus on understorey plant growth and species richness are greater in non-native regions
1
2018
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Predicting plant invasions in an era of global change
1
2010
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Changes to mineral N cycling and microbial communities in black spruce humus after additions of (NH4)2SO4 and condensed tannins extracted from Kalmia angustifolia and balsam fir
2
2000
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Biological nitrification inhibition by Brachiaria grasses mitigates soil nitrous oxide emissions from bovine urine patches
2
2017
... (1) 近年来, 从土壤氨氧化微生物(AOA, AOB)角度探讨外来植物入侵对土壤N转化的影响机制已成为研究热点(
... )的释放及其机制(
Invasive plants versus their new and old neighbors: A mechanism for exotic invasion
1
2000
...
Effects of soil biota from different ranges on Robinia invasion: Acquiring mutualists and escaping pathogens
1
2011
... 外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应.近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系.与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean.另外, 入侵植物的化感作用也会影响植物与AMF的共生关系,
Novel weapons: Invasive success and the evolution of increased competitive ability
2
2004
...
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Soil fungi alter interactions between the invader Centaurea maculosa and North American natives
1
2004
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
Soil biota and exotic plant invasion
1
2004
...
Effects of exotic and native tree leaf litter on soil properties of two contrasting sites in the Iberian Peninsula
1
2012
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Leaf litter mixtures alter microbial community development: Mechanisms for non-additive effects in litter decomposition
1
2013
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
Differential responses of invasive and native plants to warming with simulated changes in diurnal temperature ranges
1
2017
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Effects of aqueous extracts of Mikania micrantha on litter decomposition of native plants in South China
1
2007
... 植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(
Effects of aqueous extracts of Mikania micrantha HBK on nutrients release from the forests litter at three succession stages in South China
2
2009
... 植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Non-additive effects on decomposition from mixing litter of the invasive Mikania micrantha H.B.K. with native plants
2
2013
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
外来植物薇甘菊对本地植物凋落物分解的影响
1
2008
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
外来植物薇甘菊对本地植物凋落物分解的影响
1
2008
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Effects of the invasive plant Mikania micrantha H.B.K. on soil nitrogen availability through allelopathy in South China
5
2009
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
...
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... )含量和硝化速率(
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
丛枝菌根真菌在土壤氮素循环中的作用
1
2014
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
丛枝菌根真菌在土壤氮素循环中的作用
1
2014
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
Secondary metabolites of Pinus halepensis alter decomposer organisms and litter decomposition during afforestation of abandoned agricultural zones
1
2014
... 植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(
Plant secondary metabolites: A key driver of litter decomposition and soil nutrient cycling
1
2016
... 植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(
Microbes as targets and mediators of allelopathy in plants
1
2012
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Litter quality influences on decomposition, ectomycorrhizal community structure and mycorrhizal root surface acid phosphatase activity
1
2000
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
Multiple effects of secondary metabolites on amino acid cycling in white clover rhizosphere
1
2018
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Long-term dynamics and impacts of plant invasions
1
2017
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Biological invasions by exotic grasses, the grass/fire cycle, and global change
1
1992
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Niche construction by the invasive Asian knotweeds (species complex Fallopia): Impact on activity, abundance and community structure of denitrifiers and nitrifiers
1
2011
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
Identifying the role of soil microbes in plant invasions
2
2016
...
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
Nitrification driven by bacteria and not archaea in nitrogen-rich grassland soils
1
2009
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Strong response of an invasive plant species ( Centaurea solstitialis L.) to global environmental changes
1
2011
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Effects of exotic plant invasions on soil nutrient cycling processes
4
2003
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
...
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
Ecosystem consequences of biological invasions
1
2010
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
Exotic plant invasion alters nitrogen dynamics in an arid grassland
2
2001
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
Exotic or not, leaf trait dissimilarity modulates the effect of dominant species on mixed litter decomposition
1
2016
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
Leaf litter traits of invasive species slow down decomposition compared to Spanish natives: A broad phylogenetic comparison
1
2010
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Biodiversity and litter decomposition in terrestrial ecosystems
2
2005
...
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
The importance of nitrogen-fixation for an invader of a coastal California grassland
1
2011
...
Arbuscular mycorrhizal assemblages in native plant roots change in the presence of invasive exotic grasses
1
2006
...
Plant invasion alters nitrogen cycling by modifying the soil nitrifying community
6
2005
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
...
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
Impact of an exotic N2-fixing
1
2011
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
Impact of an invasive alien plant on litter decomposition along a latitudinal gradient
1
2018
... 植物释放的化感物质会影响凋落物的分解与养分释放, 这主要与化感物质影响土壤生物(微生物、小动物)活性有关(
Allelopathy and exotic plant invasion
2
2003
...
... 除了认识外来入侵植物的化感作用对土壤微生物的影响(
空心莲子草在不同生境中氮素迁移和表型可塑性差异
1
2018
...
空心莲子草在不同生境中氮素迁移和表型可塑性差异
1
2018
...
氮碳添加和丛枝菌根对外来入侵植物豚草的影响
1
2010
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
氮碳添加和丛枝菌根对外来入侵植物豚草的影响
1
2010
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
Impacts of soil microbial communities on exotic plant invasions
2
2010
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
... )与土壤微生物的结构与功能(
Volatile chemicals from leaf litter are associated with invasiveness of a Neotropical weed in Asia
1
2011
...
The ecosystem and evolutionary contexts of allelopathy
2
2011
...
... 除了认识外来入侵植物的化感作用对土壤微生物的影响(
High abundance of ammonia-?oxidizing archaea in acidified subtropical forest soils in southern China after long-term N deposition
1
2012
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Are there benefits of simultaneous root colonization by different arbuscular mycorrhizal fungi?
1
2008
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
Invasive plants accelerate nitrogen cycling: Evidence from experimental woody monocultures
3
2017
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
...
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
Soil enzyme inhibition by condensed litter tannins may drive ecosystem structure and processes: The case of Kalmia angustifolia
2
2007
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Hyphal transport of 15N-labelled nitrogen by a vesicular-arbuscular mycorrhizal fungus and its effect on depletion of inorganic soil N
1
1992
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
Leaf litter variation influences invasion dynamics in the invasive wetland grass
1
2013
...
Mechanisms of plant species impacts on ecosystem nitrogen cycling
1
2002
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Isolation of an autotrophic ammonia-oxidizing marine archaeon
1
2005
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Decomposition and nutrient release from C3 and C4 plant litters in a natural grassland
1
1998
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Differences in earthworm densities and nitrogen dynamics in soils under exotic and native plant species
1
1999
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
Exotic plant species alter the microbial community structure and function in the soil
1
2002
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
Experimental analysis of the effect of exotic and native plant species on the structure and function of soil microbial communities
1
2003
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
Ammonia-oxidizing bacteria: A model for molecular microbial ecology
1
2001
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Archaea predominate among ammonia-oxidizing prokaryotes in soils
2
2006
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
... )等多种陆地生态系统土壤中, 且数量远高于AOB (
Fungal and bacterial responses to phenolic compounds and amino acids in high altitude barren soils
1
2002
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
紫茎泽兰入侵对土壤微生物、酶活性及肥力的影响
2
2009
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
紫茎泽兰入侵对土壤微生物、酶活性及肥力的影响
2
2009
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
闽江口互花米草入侵过程对短叶茳芏沼泽沉积物硝化-反硝化作用的影响
2
2017
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
... 除了认识外来入侵植物的化感作用对土壤微生物的影响(
闽江口互花米草入侵过程对短叶茳芏沼泽沉积物硝化-反硝化作用的影响
2
2017
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
... 除了认识外来入侵植物的化感作用对土壤微生物的影响(
黄顶菊入侵对土壤氨氧化古菌群落多样性的影响
1
2017
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
黄顶菊入侵对土壤氨氧化古菌群落多样性的影响
1
2017
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
Changes in soil microbial communities due to biological invasions can reduce allelopathic effects
2017
Altered ecosystem carbon and nitrogen cycles by plant invasion: A meta-analysis
4
2008
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
Elevated nitrogen allows the weak invasive plant Galinsoga quadriradiata to become more vigorous with respect to inter-specific competition
1
2018
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
外来植物豚草入侵对土壤碳氮转化的影响
1
2016
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
外来植物豚草入侵对土壤碳氮转化的影响
1
2016
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
Differential impact on soil microbes of allelopathic compounds released by the invasive Acacia dealbata Link
2
2013
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
... ;
Exotic grasses alter controls over soil nitrogen dynamics in a Hawaiian woodland
1
2003
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
Alteration of ecosystem nitrogen dynamics by exotic plants: A case study of C4 grasses in Hawaii
2
2001
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
A native nitrogen-fixing shrub facilitates weed invasion
2
1996
...
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
Exotic invasive plants increase productivity, abundance of ammonia-oxidizing bacteria and nitrogen availability in intermountain grasslands
5
2016
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
... )对入侵地N转化的影响, 发现入侵不仅改变了AOB的丰度, 也改变了AOA的丰度.
Reciprocal effects of litter from exotic and congeneric native plant species via soil nutrients
1
2012
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Effects of root extracts of Mikania micrantha HBK on soil microbial community
1
2006
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
The effects of soil biota and fertilization on the success of Sapium sebiferum
2
2008
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
... (2) AMF能够与大部分入侵植物, 尤其是草本入侵植物的根系形成共生关系(
An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition
1
2013
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
Carbon and nitrogen dynamics during the decomposition of litter and roots of a Chihuahuan desert annual,Lepidium Lasiocarpum
1
1984
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Do novel weapons that degrade mycorrhizal mutualisms promote species invasion?
1
2018
... 外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应.近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系.与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean.另外, 入侵植物的化感作用也会影响植物与AMF的共生关系,
Smooth brome changes gross soil nitrogen cycling processes during invasion of a rough fescue grassland
2
2015
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
... ).
A global assessment of invasive plant impacts on resident species, communities and ecosystems: The interaction of impact measures, invading species’ traits and environment
1
2012
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
The relative importance of allelopathy in interference: The effects of an invasive weed on a native bunchgrass
1
2001
...
The invasive species Alliaria petiolata(garlic mustard) increases soil nutrient availability in northern hardwood conifer forests
2
2008
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
Belowground mutualists and the invasive ability of Acacia longifolia in coastal dunes of Portugal
2
2009
... 外来入侵植物影响土壤真菌、细菌和病原菌的群落结构(
... 外来入侵植物有时能增加有利于自身生长的AMF种类, 降低本地植物通过菌根吸收养分(特别是N)的能力, 从而使其在与本地植物的竞争中占据优势, 这说明AMF对入侵植物具有正反馈效应.近期研究发现3种外来入侵植物虎杖(Reynoutria japonica) (非AMF共生植物), 金光菊(Rudbeckia laciniate)(与AMF共生)和Solidago gigantean (与AMF共生)都明显降低了AMF的丰度, 这种影响取决于入侵植物与AMF的共生关系.与本地植物相比, 非AMF共生的入侵植物虎杖对AMF丰度的影响明显大于其他两种与AMF共生的入侵植物金光菊和Solidago gigantean.另外, 入侵植物的化感作用也会影响植物与AMF的共生关系,
The influence of an invasive plant on denitrification in an urban wetland
2
2018
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
... )单优群落沉积物的反硝化作用, 发现反硝化作用变化较大, 外来植物芦苇的入侵对反硝化作用的影响并不显著(
Increased sediment accretion rates following invasion by Phragmites australis: The role of litter
1
2003
... 土壤的硝化作用与反硝化作用是两个伴随发生的动态过程.许多研究表明外来植物入侵提高了土壤的无机N含量与硝化速率(
An exotic tree alters decomposition and nutrient cycling in a Hawaiian montane forest
1
2004
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Functional diversity affects decomposition processes in experimental grasslands
1
2008
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
The role of ammonium oxidizing communities in mediating effects of an invasive plant on soil nitrification
3
2015
...
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
... (1) 近年来, 从土壤氨氧化微生物(AOA, AOB)角度探讨外来植物入侵对土壤N转化的影响机制已成为研究热点(
Lantana invasion alters soil nitrogen pools and processes in the tropical dry deciduous forest of India
1
2009
... 可见, 外来入侵植物的凋落物通常具有较高的N含量, 其凋落物分解速率较快, 这会加快凋落物中N的释放进而提高土壤N的可利用性, 有利于其进一步入侵(
加拿大一枝黄花对土壤微生物区系的影响研究
1
2007
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
加拿大一枝黄花对土壤微生物区系的影响研究
1
2007
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
Future-proofing weed management for the effects of climate change: Is New Zealand underestimating the risk of increased plant invasions?
1
2016
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Acclimation of photosystem II to high temperature in two Wedelia species from different geographical origins: Implications for biological invasions upon global warming
1
2010
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Elevated CO2 increases energy-use efficiency of invasiveWedelia trilobata over its indigenous congener
1
2010
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Relationships between phenolics and soil microorganisms in spruce forests: Significance for natural regeneration
2
2000
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
... ), 进而影响土壤的N转化过程(
Soil biochemical alterations and microbial community responses under Acacia dealbata Link invasion
1
2014
... 反硝化作用是在反硝化细菌的作用下将土壤中的硝酸盐还原成N2和N2O的过程.外来植物入侵能够改变反硝化细菌的群落结构与功能(
The invasive annual cheatgrass increases nitrogen availability in 24-year-old replicated field plots
1
2015
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
Nitrogen and lignin content as predictors of litter decay rates: A microcosm test
1
1989
... 外来入侵植物对N循环的影响除了与其凋落物累积量和凋落物分解速率有关, 还与被入侵生态系统本地植物的凋落物分解与养分释放有关.许多研究表明凋落物分解速率与凋落物的N含量、碳氮比(C:N)、单宁与N的比值(lignin:N)、木质素与氮(cellulose:N)的比值呈负相关关系, 与凋落物的N含量呈正相关关系(
Phenolic inputs by invasive species could impart seasonal variations in nitrogen pools in the introduced soils: A case study with Polygonum cuspidatum
1
2013
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Biogeographic differences in the effects of Centaurea stoebe on the soil nitrogen cycle: Novel weapons and soil microbes
2
2011
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... )的根系分泌物儿茶素(-catechin)显著降低了土壤的硝化速率(
Root exudate is allelopathic in invaded community but not in native community: Field evidence for the novel weapons hypothesis
1
2009
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Novel genes for nitrite reductase and Amo-related proteins indicate a role of uncultivated mesophilic crenarchaeota in nitrogen cycling
1
2005
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Role of allelopathy of Phragmites australis in its invasion processes
2
2017
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Microbial ecology of biological invasions
1
2007
...
Environmental genome shotgun sequencing of the Sargasso Sea
1
2004
... 土壤微生物是生态系统N循环的关键驱动因素, 氨氧化微生物是影响土壤硝化作用的限速因子 (
Arbuscular mycorrhiza and soil nitrogen cycling
2
2012
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
... (2) AMF能够与大部分入侵植物, 尤其是草本入侵植物的根系形成共生关系(
Arbuscular mycorrhizal modulation of diazotrophic and denitrifying microbial communities in the (mycor) rhizosphere of Plantago lanceolata
1
2012
... 丛枝菌根真菌(AMF)在自然界分布广泛, 它能够与大部分高等植物的根系形成共生关系(
Ecological impacts of invasive alien plants: A meta-analysis of their effects on species, communities and ecosystems
1
2011
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Biogeographical variation in community response to root allelochemistry: Novel weapons and exotic invasion
1
2004
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
Input of organic matter to the soil by tree roots
1
1991
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
Defoliation effects on arbuscular mycorrhizae and plant growth of two native bunchgrasses and an invasive forb
1
2006
... 外来入侵植物, 尤其是入侵草本植物具有较高的菌根侵染率(
紫茎泽兰叶片凋落物对入侵地4种草本植物的化感作用
1
2011
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
紫茎泽兰叶片凋落物对入侵地4种草本植物的化感作用
1
2011
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Insights into ecological effects of invasive plants on soil nitrogen cycles
1
2015
... 生物入侵已经成为影响全球生态环境和经济的重大问题.外来入侵植物对生物多样性及生态系统的结构与功能具有显著影响(
Insights into the role of plant on ammonia-oxidizing bacteria and archaea in the mangrove ecosystem
1
2015
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
Responses of Mikania micrantha, an invasive weed to elevated CO2: Induction of β-Caryophyllene synthase, changes in emission capability and allelopathic potential of β-Caryophyllene
1
2010
... (3) 全球变化(如CO2浓度升高、增温、N沉降等)会影响外来入侵植物的能量利用效率、资源分配、化感物质合成等诸多特性(
Allelopathic invasive tree (Rhamnus cathartica) alters native plant communities
1
2017
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Use of an artificial root to examine the influence of 8-hydroxyquinoline on soil microbial activity and bacterial community structure
2
2009
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
... ;
Net impact of a plant invasion on nitrogen-cycling processes within a brackish tidal marsh
2
2003
... N循环过程主要包括: 植物对N的吸收利用、枯枝落叶对土壤N的输入、土壤微生物对N的固定、土壤不同形态N之间的转换、N释放等过程.目前, 外来入侵植物影响土壤N循环的研究主要是通过比较外来植物与本地植物对土壤的总N含量、无机N含量、矿化速率、硝化速率和反硝化速率影响的差异, 以及对比研究外来入侵植物与本地植物的凋落物分解与养分释放的差异, 进而阐述外来入侵植物对土壤N转化过程的影响(
... 凋落物分解与养分释放是生态系统养分循环中的重要过程(
pH drives ammonia oxidizing bacteria rather than archaea thereby stimulate nitrification under Ageratina adenophora colonization
1
2017
... (1) 近年来, 从土壤氨氧化微生物(AOA, AOB)角度探讨外来植物入侵对土壤N转化的影响机制已成为研究热点(
Ecosystem level impacts of invasive Acacia saligna in the South African fynbos
1
2004
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
不同生境条件下紫茎泽兰化感作用的变化与入侵力关系的研究
1
2004
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
不同生境条件下紫茎泽兰化感作用的变化与入侵力关系的研究
1
2004
... 许多研究证实外来入侵植物的化感作用会抑制本地植物的生长, 化感作用被认为是其成功入侵的“新奇武器” (
Impacts of Spartina alterniflora invasion on abundance and composition of ammonia oxidizers in estuarine sediment
2
2011
... 近年来, 基于AOA与AOB探究外来植物入侵引起土壤N转化改变的微生物机制已成为入侵生态学的研究热点.野外调查研究发现, 外来植物入侵显著改变土壤氨氧化微生物群落结构, 进而影响N循环过程(
... ).
The invasive plant Solidago canadensis L. suppresses local soil pathogens through allelopathy
1
2009
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
崇明东滩湿地不同潮汐带入侵植物互花米草根际细菌的多样性
1
2012
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
崇明东滩湿地不同潮汐带入侵植物互花米草根际细菌的多样性
1
2012
... 外来植物成功入侵之后, 能够提高固N微生物的固N能力与土壤N水平, 这有利于其进一步入侵.
外来植物对陆地生态系统氮循环的影响途径
1
2011
...
外来植物对陆地生态系统氮循环的影响途径
1
2011
...
Response of soil bacterial communities to secondary compounds released from Eupatorium adenophorum
2
2017
... 探讨入侵植物化感作用对土壤微生物结构与功能的影响能够更好地认识外来入侵植物的化感作用对土壤N转化的影响机制.许多研究表明：入侵植物释放的化感物质能够影响土壤微生物群落结构与功能(
... ;
Invasive plants affect arbuscular mycorrhizal fungi abundance and species richness as well as the performance of native plants grown in invaded soils
1
2016
... 除了认识外来入侵植物的化感作用对土壤微生物的影响(
