Drives of environmental factors in shaping rubber tree fungal community
Among all environmental factors, leaf water content (WC), temperature, and precipitation were identified as the most important predictors of fungal alpha diversity in different compartments (Figure 4, Figure S5b). These findings were further supported by simple linear and nonlinear regression analyses. For instance, significant and positive simple linear regressions were observed between leaf WC, temperature, and fungal alpha diversity in the leaf endosphere and root endosphere compartments. Additionally, a similar mid-peak pattern was observed in four datasets, where richness peaked at mid-temperature in the phyllosphere and rhizosphere compartments, and peaked at mid-precipitation in the soil and rhizoplane compartments. These results indicate that climatic factors play a significant role in driving the alpha diversity of fungi in rubber tree ecosystems.
The major physicochemical and climatic factors to the fungal composition were further identified using the Mantel tests. Of the most important environmental factors contributing to the leaf composition, leaf P had the largest observed effect, followed by temperature and precipitation, while soil AK affect the composition most in all root- associated compartments (Figure 5, Table S2). Specifically, temperature and precipitation were significantly correlated with the fungal communities in different compartments to a certain extent (Table S2). The contributions of seasonal, environmental, climatic and geographic variables to the variation in fungal composition were quantified by variation partitioning (VPA). Geographic factors were better predictors of fungal composition than seasonal, environmental and climatic ones (Figure 6), confirming a stronger effect of spatial variation in driving the composition of soil fungi.