土壤磷和白蚁驱动的不同类型菌根植物凋落物分解机制

凋落物分解是土壤养分输入与循环的重要过程，它与陆地生态系统碳、氮和磷等养分循环密切相关。我国具有丰富的亚热带森林类型，多样性属东亚最高，缺乏磷元素。一方面，90%以上的高等植物可与丛枝菌根真菌AM和外生菌根真菌ECM结合，促进植物从土壤和凋落物分解过程中获取必需的养分物质（如不同形态的磷）；另一方面，白蚁作为亚热带地区最重要的分解者之一，其分解作用受凋落物量和性质的影响，并与土壤中真菌类型相关。现有大部分研究证明了陆地生态系统小尺度上凋落物分解主要受土壤微生物的调节，但有关AM、ECM真菌与白蚁互作驱动凋落物分解的研究仍匮乏。本项目拟以南亚热带常绿阔叶林为研究对象，采用群落调查和野外控制实验相结合的方法，探讨自然群落中土壤磷和白蚁对AM、ECM树种凋落物分解的影响及差异，揭示凋落物分解过程中“土壤磷-菌根真菌-白蚁”跨营养级的协作机制，完善森林群落养分循环和物种共存理论。

Litter decomposition is one of the most important ecosystem processes, which plays a critical role in regulating soil nutrient inputs and cycling. High-biodiversity subtropical forest distributed widely in China, featured with lacking phosphorus (P). More than 90% of higher plants are associated with arbuscular mycorrhizal (AM) fungi and ectomycorrhizal (ECM) fungi to facilitate to obtain the necessary nutrients (e.g. P) for growth from soil and the process of litter decomposition. As an important decomposers in subtropical forest ecosystems, termites control the litter decomposition through the properties and quantity of litter substrate, which also associate with multi-types of fungi in the soil. Abundant researches demonstrated that litter decays at a small scale is often regulated by soil microbes. However, the interactions between multi-types mycorrhizal fungi and termites are rarely studied. In this project, we will try to address these questions by focusing on the South China subtropical evergreen broad-leaved forest, with combined methods of forest monitoring details data analysis, field survey and field control experiments. In order to reveal the soil phosphorus-mycorrhizal fungi-termites interaction in litter decomposition process, the effects and differences of soil phosphorus on litter decomposition of AM and ECM species were analyzed and discussed in natural communities.