森林生态系统叶际真菌的群落与网络结构对模拟氮沉降的响应机制

森林生态系统具有丰富的动植物和微生物多样性以及重要的生态服务功能。然而，全球环境变化，如外源氮输入对森林生态系统的物种多样性、群落结构及其生态功能产生严重影响。作为森林生态系统的重要微生物组分，植物叶际真菌(包括表生真菌和内生真菌)在生态系统的多样性维持、群落构建以及物质和能量循环过程中发挥重要作用。然而，目前对森林叶际表生真菌和内生真菌的多样性、群落组成、网络结构及其对氮沉降的响应机制知之甚少。因此，为了揭示此科学问题，本项目依托建立于河南信阳鸡公山国家自然保护区的林冠/林下模拟氮沉降实验的固定样地平台，利用DNA高通量测序技术和生态网络模型分析方法，揭示叶际表生真菌与内生真菌的多样性、群落组成和网络结构特性的差异及其对氮沉降的响应机制。本项目从叶际真菌的角度阐明森林生态系统对氮沉降的响应机理，将对全面揭示全球环境变化背景下森林生态系统的多样性维持机制及其生态功能提供重要的科学理论依据。

Forest ecosystems have high species diversities of animals, plants and microorganisms and play important ecological service functions. However, global environmental changes, such as nitrogen deposition, strongly influence biodiversity, community structure and ecological functions in forest ecosystems. Phyllosphere epiphytic and endophytic fungi, as an important component of forest microorganisms, have important functions in biodiversity maintenance, community assembly, and substance and energy cycling in ecosystems. However, we know little about the differences in diversity, community and network structure between phyllosphere epiphytic and endophytic fungi, and their response mechanism to simulated nitrogen deposition in forest ecosystems. Therefore, in order to answer these scientific questions, we plan to conduct the study in a mixed deciduous forest with canopy and understory nitrogen addition, located at Jigongshan National Nature Reserve in Henan Province, China. We utilize Illumina MiSeq sequencing technique and ecological network analysis to detect the differences of phyllosphere epiphytic and endophytic fungi in richness, community composition and network structure and their response mechanisms to nitrogen fertilization. This proposal will elucidate the response mechanism of forest ecosystem to nitrogen fertilization from the aspect of phyllosphere fungi, and offer us new insights into the mechanism of biodiversity maintenance and ecosystem function under global environmental changes.