Data from: Soil fungal communities of grasslands are environmentally structured at a regional scale in the Alps

Studying patterns of species distributions along elevation gradients is frequently used to identify the primary factors that determine the distribution, diversity and assembly of species. However, despite their crucial role in ecosystem functioning, our understanding of the distribution of below-ground fungi is still limited, calling for more comprehensive studies of fungal biogeography along environmental gradients at various scales (from regional to global). Here, we investigated the richness of taxa of soil fungi and their phylogenetic diversity across a wide range of grassland types along a 2800 m elevation gradient at a large number of sites (213), stratified across a region of the western Swiss Alps (700 km2). We used 454 pyro-sequencing to obtain fungal sequences that were clustered into operational taxonomic units (OTUs). The OTU diversity-area relationship revealed uneven distribution of fungal taxa across the study area (i.e. not all taxa are everywhere) and fine-scale spatial clustering. Fungal richness and phylogenetic diversity were found to be higher in lower temperatures and higher moisture conditions. Climatic and soil characteristics as well as plant community composition were related to OTU alpha, beta and phylogenetic diversity, with distinct fungal lineages suggesting distinct ecological tolerances. Soil fungi, thus, show lineage-specific biogeographic patterns, even at a regional scale, and follow environmental determinism, mediated by interactions with other taxonomic groups, such as plants.

沿海拔梯度探究物种分布模式，是学界用以明确物种分布、多样性与群落构建核心驱动因子的常用研究路径。然而，尽管地下真菌在生态系统功能中发挥着至关重要的作用，但当前学界对其分布格局的认知仍较为有限，亟需开展更多不同尺度（从区域到全球）下沿环境梯度的真菌生物地理学综合研究。本研究沿瑞士西部阿尔卑斯山区一片700平方千米的区域，在213个分层布设的样地中，针对覆盖2800米海拔梯度的多种草地类型，调查了土壤真菌的类群丰富度及其系统发育多样性。本研究采用454焦磷酸测序（454 pyro-sequencing）技术获取真菌序列，并将序列聚类为操作分类单元（operational taxonomic units, OTU）。基于OTU的多样性-面积关系分析结果显示，研究区内真菌类群的分布并不均匀（即并非所有类群均广布），且存在精细尺度的空间聚集现象。研究发现，真菌类群丰富度与系统发育多样性在温度较低、湿度较高的生境中更高。气候与土壤特征，以及植物群落组成，均与OTU的α、β多样性及系统发育多样性存在关联；不同的真菌谱系展现出各异的生态耐受特征。因此，即便在区域尺度下，土壤真菌也呈现出谱系特异性的生物地理分布格局，且遵循由与植物等其他生物类群相互作用介导的环境决定论规律。