放牧采食对丛枝菌根真菌菌丝网络中养分分配的影响

项目名称： 放牧采食对丛枝菌根真菌菌丝网络中养分分配的影响

项目编号： No.31501996

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 林学

项目作者： 杨高文

作者单位： 南京农业大学

项目金额： 22万元

中文摘要： 丛枝菌根真菌（AMF）能够与约80%的草地植物形成菌根共生体，帮助宿主植物吸收氮磷等养分。AMF在土壤中形成大量菌丝网络，同时与多种植物形成菌根共生体。菌丝网络将不同植物联系在一起，能够在不同植物间进行养分的再分配，影响物种间的竞争关系，从而作用于植物群落生产力和物种多样性。我国草地资源丰富，放牧是草地的主要利用方式之一。然而，放牧采食对草地生态系统土壤AMF菌丝网络养分分配的影响还研究得较少。本项目利用同位素示踪法研究放牧的选择性采食、采食强度和采食上层植物对天然草地土壤中菌丝网络养分分配的影响，结合植物群落变化，探索放牧干扰下菌丝网络的养分分配规律与植物群落生产力以及物种多样性的关系。该项目研究结果有助于解释放牧草地生产力和生物多样性的维持机制，丰富放牧管理的生态学理论基础，为我国草地的放牧管理提供科学依据。

中文关键词： 家畜放牧；放牧强度；丛枝菌根真菌；植物群落；多样性

英文摘要： Arbuscular mycorrhizal fungi (AMF) can form mycorrhizal symbioses with 80% of plant species in grasslands, and play critical roles in nitrogen and phosphorus acquisition for their host plants. AMF produce a large number of mycorrhizal networks， and form mycorrhizal symbioses with multiple plant species simultaneously. Mycorrhizal networks can interconnect multiple plant hosts and species, and lead to reallocation of nutrients among plants，influencing competition between plants. China is rich in grassland resources and livestock grazing is the major way of grassland resources utilization. However, the effect of defoliation by livestock on nutrient allocation in mycorrhizal networks of AMF at grazing steppe is still poorly understood. The present project will investigate the effects of selective defoliation, defoliation intensity, and defoliation of upper-layer plants on nutrient allocation of mycorrhizal networks using isotopic tracer method, and explore the relationships between nutrient allocation and the dynamic of plant community productivity and species diversity in native grassland. The results will contribute to the maintaining mechanism of plant community productivity and biodiversity, enrich the ecological theory basis of grazing and grassland management, and provide scientific support for grassland management.

英文关键词： livestock grazing;Grazing intensity;Arbuscular mycorrhizal fungi;Plant community;Diversity