中亚热带森林土壤微生物多样性对植物物种共存关系的影响

A growing body of experiments have put insight into plant coexistence in forest ecosystems, but nevertheless these experiments focus on aboveground processes. Theory and empirical evidences indicate that plant community can alter soil nutrient pool size by influencing carbon input into soils and consequently modulate soil microbial diverisity, which in turn shape plant growth and community composition. However, the role of soil microbial diversity in plant-soil feedback is often overlooked. The project is to test the mechanisms underlying microbial-driven plant species coexistence. Three experments have been designed to solve the scientific issue.1) The first experiment aims to test the Miki's hypothesis that soil microbial diversity may act as a buffer weakening plant control over soil nutrient and availability, and thus facilitate plant species coexistence. Here we plan to detect the spatial pattern of soil microbial communities between adjacent tree species in 24 sites of the subtrophic forests in Zhejiang Province.2)the second is to elucidate the effects of soil microbial diversity on plant species coexistence through controling soil nitrogen and phosphorus availability. 3) The third is a cross inoculation experiment, which is designed to detect how altered microbial diversity modify plant species coexistence. Overall, the project would advance our mechanistic understanding of how soil microbial diversiy influence plant species coexistence, and has great implications for the protection of plant diversity in the subtrophic forests of sourthern China.

植物物种共存机制是当前森林群落生态学研究的核心科学问题，也是森林生物多样性保护的理论基础。然而,以往研究大多是侧重在地上过程，对土壤微生物多样性如何影响植物共存关系并不了解。目前，已有的关于微生物机制的研究主要侧重在模型模拟和理论假设层面，尚无相关实验性的研究报道。本项目通过多位点原位实验、栽培实验和交叉接种控制实验，针对分解者亚系统土壤微生物多样性对植物共存关系的影响开展研究。研究内容包括：1）浙江省亚热带森林24个长期监测位点相邻树种小立地内土壤微生物多样性的空间格局及其作用机制，用以验证Miki等提出的理论假设；2）通过增减土壤养分有效性，反推土壤微生物多样性对相邻树种共存关系的影响；3）通过交叉接种控制实验互换异质土壤的微生物菌群用以分析微生物多样性变化对植物共存关系的作用机制。本项目旨在揭示亚热带森林生态系统植物物种共存的微生物机制，为我国亚热带森林生物多样性保护提供理论依据。

植物物种共存机制是当前森林群落生态学研究的核心科学问题，也是森林生物多样性保护的理论基础。然而，以往研究大多是侧重在地上过程，对土壤微生物多样性如何影响植物共存关系并不了解。目前已有的关于微生物机制的研究主要侧重在模型模拟和理论假设层面，尚无相关试验性的研究报道。本项目通过多位点原位实验、栽培实验和交叉接种控制实验，针对植物群落和土壤微生物群落关联性开展研究。研究结果发现：1）亚热带不同林型植物群落组成与土壤微生物密切关联；2）源于所选相邻树对不同位置的土壤对所选树种生长具有物种依赖性；3）土壤分解者及其介导的分解过程对植物生长具有显著地反馈调节作用。这些研究结果揭示了土壤微生物、尤其是分解者类群在植物生长过程中的反馈调节作用，这一成果突破了植物物种共存和生物多样性研究领域对真菌分解者及其介导的分解过程的长期忽视，为探讨群落生态学植物物种共存机制这一核心科学问题拓展了新的思路。