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.