植物种间作用和病原菌负反馈对超产效应的影响研究

植物种间作用和病原菌负反馈是目前解释植物多样性产生超产效应的两类主要机制。针对两类机制实验结果存在的争议，本研究拟以人工控制草地为研究对象，通过调控植物种间邻体关系，形成种间作用效应梯度（弱和强），同时考虑病原菌负反馈作用（存在和不存在）的影响，探讨下列问题：①植物种间作用和病原菌负反馈是否可以单独产生超产效应？在植物群落中是否可以同时对超产效应产生影响？②两者间是否存在交互作用？当种间作用机制主要是互补效应时，两者对超产效应是否产生正相互作用？当种间作用机制主要是选择效应时，两者对超产效应是否产生拮抗作用？同时，结合不同环境条件下的自然草地原位验证实验，检验人工控制实验结果是否具有普遍性，并分析影响两类作用机制发挥作用的调控因子。如果本研究取得预期结果，将会进一步完善植物多样性导致超产效应的理论体系，同时，为解决两类实验结果产生的争议提供合理的理论解释。

Plant interspecific interactions and pathogen negative feedback are two important mechanisms to explain overyielding of plant diversity. However, experimental results of the two mechanisms still exist controversy. In order to find reasons of the controversy, interspecific neighbor distribution of plants in artificial grassland is regulated to control the plant interspecific interaction effect, and simultaneously consider the effect of pathogen negative feedback. Several questions as follows are explored: ①Can the plant interspecific interactions or the pathogen negative feedback produce the overyielding alone? And can they simultaneously affect the overyielding in a plant community? ②Is there interactive effect between the two mechanisms? If the plant interspecific interactions affect overyielding mainly through complementarity effect, whether there is positive interactive effect between them? If the plant interspecific interactions affect overyielding mainly through selection effect, whether there is negative interactive effect between them? Then, experiments constructed in natural grasslands of different environmental conditions are used to test the results of artificial grasslands, and further find the regulatory factors that affect the effects of two mechanisms on overyielding. If answers of questions described above are yes, the theoretical system that explain the overyielding of plant diversity will be greatly improved, and also provide a reasonable explanation for the controversy of experimental results of two mechanisms.