Increasing evidence suggests that elevational gradients of soil fungal richness are highly variable, but few studies have examined how diversity components of each guild contribute to overall fungal diversity. Here, we aimed to disentangle the relationships between total, saprotrophic, and ectomycorrhizal fungal richness, and environmental factors across elevational gradients in cool-temperate montane forests. We observed that total and saprotrophic richness decreased but ectomycorrhizal richness increased with increase in elevation. Elevational range size and nestedness analyses illustrated that saprotrophic and ectomycorrhizal source communities were located at lower and higher elevations, respectively. The observed total and saprotrophic richness were directly influenced by soil properties and indirectly influenced by climate and plant communities. Ectomycorrhizal fungal richness was affected by climate and the dominance of ectomycorrhizal trees. We highlight that two directional source–sink dynamics lead to opposite elevational patterns between saprotrophic and ectomycorrhizal fungal richness, shaping the variation in elevational richness gradients.

越来越多的证据表明，土壤真菌丰富度的海拔梯度变化很大，但是很少有研究检查每个行会的多样性成分如何对总体真菌多样性做出贡献。在这里，我们的目的是弄清在温带山地森林中总海拔，腐生真菌和外生菌根真菌的丰富度与海拔梯度上的环境因素之间的关系。我们观察到总的和腐生的丰富度降低了，但是外生菌根的丰富度随着海拔的升高而增加了。高度范围的大小和嵌套分析表明，腐养和根外菌根源群落分别位于较低和较高的海拔。观测到的总养分和腐生养分的丰富度直接受到土壤性质的影响，而间接受到气候和植物群落的影响。外生菌根真菌的丰富度受到气候和外生菌根树种优势的影响。我们着重指出，两个方向的源－汇动力学导致腐化和外生菌根真菌丰富度之间相反的海拔模式，从而塑造了海拔丰富度梯度的变化。