Investigating the effects of individual tree species on fungal species in leaf litter allows a mechanistic understanding of how tree diversity affects the diversity and composition of fungal species at the community level. We collected freshly-fallen leaves of eight focal tree species at four tree species richness levels in a large-scale subtropical forest diversity experiment to estimate tree species richness effects on fungal species diversity and community composition at two spatial scales: at the local tree neighbourhood and at the tree community level. The identity of focal tree species affected both the diversity and composition of the fungal community in freshly-fallen leaves, particularly structuring the composition of both the pathogenic and non-pathogenic fungal community. Furthermore, we found that the effects of community tree species richness on fungal OTU composition were tree species-specific. Besides community tree species richness, the neighbour tree community had significant effects on the structure of the entire fungal community and of functional groups in freshly-fallen leaves. These findings highlight that the response of fungal species assemblages to tree species richness depends on fungal-associated tree species identity, and suggest that heterospecificity of local tree neighbours is an important driver of tree richness effects on litter fungal community.

调查单个树木物种对凋落物中真菌物种的影响，可以从机械角度了解树木多样性如何在社区一级影响真菌物种的多样性和组成。在大规模的亚热带森林多样性实验中，我们收集了四个树种丰富度水平下的八种重点树种的新鲜落叶，以估计树种丰富度在两个空间尺度上对真菌物种多样性和群落组成的影响：在当地树木邻里和在树社区级别。重点树种的身份影响了刚下落叶的真菌群落的多样性和组成，特别是构造了致病性和非致病性真菌群落的组成。此外，我们发现，群落树种丰富度对真菌OTU组成的影响是树种特有的。除了群落树种丰富外，邻居树群落还对整个真菌群落的结构和新鲜落下的叶子中的功能团有重要影响。这些发现表明，真菌物种集合对树木物种丰富度的响应取决于与真菌相关的树木物种的身份，并表明本地树木邻居的异质性是树木丰富度对凋落真菌群落的重要驱动力。