Data_Sheet_1_Biogeographic Patterns of Ectomycorrhizal Fungal Communities Associated With Castanopsis sieboldii Across the Japanese Archipelago.xlsx

Biogeographic patterns in ectomycorrhizal (ECM) fungal communities and their drivers have been elucidated, including effects of host tree species and abiotic (climatic and edaphic) conditions. At these geographic scales, genotypic diversity and composition of single host tree species change with spatial and environmental gradients, reflecting their historical dispersal events. However, whether the host genotypes can be associated with the biogeographic patterns of ECM communities remains unclear. We investigated the biogeographic pattern of ECM fungal community associated with the single host species Castanopsis sieboldii (Fagaceae), whose genotypic diversity and composition across the Japanese archipelago has already been evaluated. ECM communities were investigated in 12 mature Castanopsis-dominated forests covering almost the entire distribution range of C. sieboldii, and we quantified the effect of host genotypes on the biogeographic pattern of ECM fungal communities. Richness and community composition of ECM fungi changed with latitude and longitude; these biogeographic changes of ECM community were significantly correlated with host genotypic variables. Quantitative analyses showed a higher relative explanatory power of climatic and spatial variables than that of host genotypic variables for the biogeographic patterns in the ECM community. Our results suggest historical events of host dispersal can affect the biogeographic patterns of the ECM fungal community, while their explanation power was lower than that for climatic filtering and/or fungal dispersal.

对于外生菌根真菌群落（ECM）的生态地理模式及其驱动因素，包括宿主树种和生物非气候（气候和土壤）条件的影响，已有深入研究。在这些地理尺度上，单一宿主树种的基因型多样性和组成随空间和环境梯度的变化而变化，反映了其历史上的扩散事件。然而，宿主基因型是否与ECM群落的生态地理模式相关联尚不明确。本研究针对与单一种宿主物种锥栗（Castanopsis sieboldii，属壳斗科）相关的ECM真菌群落的生态地理模式进行了调查，其基因型多样性和组成在日本列岛范围内已得到评估。对覆盖C. sieboldii几乎整个分布范围的12个成熟锥栗林中的ECM群落进行了研究，并量化了宿主基因型对ECM真菌群落生态地理模式的影响。ECM真菌的丰富度和群落组成随纬度和经度的变化而变化；这些ECM群落的生态地理变化与宿主基因型变量显著相关。定量分析表明，气候和空间变量对于ECM群落生态地理模式的影响的解释力高于宿主基因型变量。我们的研究结果提示，宿主扩散的历史事件可以影响ECM真菌群落的生态地理模式，但其解释力低于气候筛选和/或真菌扩散。