大气CO2浓度倍增时植物与土壤生物互作及其对瘤突苍耳入侵的影响

项目名称： 大气CO2浓度倍增时植物与土壤生物互作及其对瘤突苍耳入侵的影响

项目编号： No.31470575

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 冯玉龙

作者单位： 沈阳农业大学

项目金额： 88万元

中文摘要： 全球变化对外来植物入侵的影响是目前入侵生态学的研究热点，但当前研究多关注生态系统的地上部，而关于入侵植物对土壤生态系统(尤其是土壤生物)的影响以及这些影响对入侵植物的反馈作用研究甚少。本项目在不同大气CO2浓度下研究我国北方恶性外来入侵植物瘤突苍耳和两种本地近缘植物：1）根系分泌物成分、含量和化感强度的变化，根系和叶片凋落物理化性质、分解速率和化感强度的变化，2）对土壤微生物（从宏基因组学角度出发，利用新一代高通量测序技术）和线虫群落结构与功能的影响及机制，即根系分泌物、地上和地下凋落物的相对作用，3）改变了的土壤生物群落对三种植物的反馈作用及机制，即土壤微生物和线虫的相对作用，从地上植物与地下土壤生物相互作用的角度，探讨大气CO2浓度升高条件下瘤突苍耳入侵危害的变化及机制。这对认识未来气候变化条件下外来植物的入侵机理，入侵危害的演化及机制以及制定有效的防控策略等均有重要的意义。

中文关键词： 入侵植物；CO2浓度升高；土壤生物；化感作用；相互作用

英文摘要： The effect of global change on invasions of introduced plant species is one of the hotspot in invasion ecology. However, related studies mostly focused on aboveground part of the ecological systems invaded, and little effort has been made to understand the effects of invasive plants on soil ecosystem especially soil biota under doubled atmospheric CO2 concentration and the feedback effects of altered soil biota on the introduced plants themselves. Here, we planed to compare the differences in the interactions between soil biota and plants from invasive (Xanthium strumarium) versus native (X. sibiricum and Bidens biternata) species under doubled atmospheric CO2 concentration. Xanthium strumarium is an annual forb native to south Canada, north America, Mexico, Australia, and Ukraine but a noxious invasive plant in north China. We aimed to study (1) the effects of elevated CO2 on components, contents and allelopathy of root exudates, and on the characteristics, decomposition rate and allelopathy of root and leaf litters in the three species; (2) the effects of the three species on soil nematode and microbe under atmospheric and doubled atmospheric CO2, and the relative role of root exudates, and root and leaf litters; (3) the feedback effects of altered soil biota on the three plants, and the relative role of soil nematode and microbe. The main purpose of this proposal is to explore the potential change in the invasion impact by X. strumarium and related mechanisms under elevated CO2 in terms of the interactions between aboveground plants and belowground soil biota. This study is important for understanding invasion mechanisms of introduced plants and the possible change in their invasion impacts under climate change in the future, and also for making effective strategies for managing invasive plants.

英文关键词： Invasive plant;CO2 enrichment;Soil biota;Allelopathy;Interactions