宋照亮,,
郝倩,
张晓东,
杨孝民,
夏少攀,
杨伟华
天津大学表层地球系统科学研究院, 天津 300072
基金项目: 国家重点研究发展计划项目(批准号:2016YFA0601002和2017YFC0212703)和国家自然科学基金项目(批准号:41522207和41571130042)共同资助
详细信息
作者简介: 杨石磊, 男, 26岁, 硕士研究生, 环境科学(地)专业, E-mail:yangshilei@tju.edu.cn
通讯作者: 宋照亮, E-mail:songzhaoliang78@163.com
中图分类号: Q949.71+4.2;Q948.3收稿日期:2018-07-02
修回日期:2018-09-29
刊出日期:2019-01-30
Impact of grassland degradation on plant silicon distribution and phytolith carbon sequestration
Yang Shilei,Song Zhaoliang,,
Hao Qian,
Zhang Xiaodong,
Yang Xiaomin,
Xia Shaopan,
Yang Weihua
Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072
More Information
Corresponding author: Song Zhaoliang,E-mail:songzhaoliang78@163.com
MSC: Q949.71+4.2;Q948.3--> Received Date: 02 July 2018
Revised Date: 29 September 2018
Publish Date: 30 January 2019
摘要
摘要:草地生态系统中，硅（Si）不仅在植物生长过程中扮演着重要的角色，而且通过形成植硅体碳（Phytolith-Occluded Carbon，简称PhytOC）的方式参与陆地生态系统碳循环。近几十年来，由于人为干扰等因素导致的草地退化引起了广泛的关注。本研究中，我们选取了我国北方农牧交错带中30个不同退化程度的样地，分析了8种常见植物（共71个样品）地上部分Si含量和分布特征，并估算了植硅体碳产生通量。结果发现，随着草地退化的加剧，糙隐子草（Cleistogenes squarrosa）地上部分Si含量呈下降趋势，而羊草（Leymus chinensis）表现为先上升后下降的倒"V"型。不同退化程度样地植物地上部分Si平均含量分别为12.25±1.02 g/kg（轻度）、10.56±1.15 g/kg（中度）和8.06±0.93 g/kg（重度），而植硅体碳产生通量显著下降，分别为0.320±0.038 kg/（ha·a）、0.190±0.021 kg/（ha·a）和0.068±0.006 kg/（ha·a）（P < 0.05）。研究表明，草地退化对不同种类植物的Si含量和产生通量的影响不同，这可能是由于植物的功能类型不同造成的。草地退化可以导致种群结构的变化和地上净初级生产力（ANPP）的降低，从而影响草地植物地上部分Si的分布和植硅体的固碳能力。当退化严重时，初步估算北方农牧交错带内草地植物地上部分植硅体固碳速率将下降5倍以上。
关键词: 中国北方/
农牧交错带/
草地退化/
硅/
植硅体碳汇
Abstract:In grasslands, silicon(Si) not only plays an irreplaceable role during the plant growth, but also contributes significantly to the terrestrial ecosystem carbon sink in the form of phytolith-occluded carbon(PhytOC). In the past decades, grassland degradation due to the human disturbances has got much attention. In this study, we chose 30 sampling sites with different degrees of degradation in agro-pastoral ecotone of Northern China(41°3'~44°31'N, 114° 15'~122°2'E). Based on the coverage and above-ground biomass of vegetation, these sampling sites were classified into three different degraded degrees:lightly degraded grasslands(LDG), moderately degraded grasslands(MDG) and seriously degraded grasslands(SDG). Then we analyzed the Si content and distribution in the above-ground parts of 71 plants(eight typical species), and estimated the PhytOC production fluxes of degraded grasslands. The Si content of Cleistogenes squarrosa shows a decreasing trend with the degradation degree of the grasslands, while that of the Leymus chinensis shows an inverted "V" type that rises first and then falls. The Si content of plant above-ground parts in grasslands of different degradation degrees are 12.25±1.02 g/kg(lightly degraded), 10.56±1.15 g/kg(moderately degraded) and 8.06±0.93 g/kg(seriously degraded), and the production fluxes of PhytOC significantly decrease in the order of degradation degrees, being 0.320±0.038 kg/(ha·a), 0.190±0.021 kg/(ha·a) and 0.068±0.006 kg/(ha·a), respectively(P < 0.05). This article suggests that the impacts of grassland degradation on Si content and production flux of diverse plant species are different, which may be caused by the different functional types of plants. Grassland degradation can change the plant population structure and above-ground net primary productivity(ANPP) of grasslands, and then affect the distribution of Si in above-ground vegetation and the potential of phytolith carbon sequestration. As the degradation continually develops, the above-ground PhytOC production retes of grasslands in this study region can decline by more than 5 times.
Key words:Northern China/
agro-pastoral ecotone/
grassland degradation/
silicon/
phytolith carbon sequestration
PDF全文下载地址:
http://www.dsjyj.com.cn/data/article/export-pdf?id=dsjyj_11576
