Effects of Soil Moisture Change on Tree Community and Soil Microbial Community Diversity

This study focused on the 25 hm² subtropical forest plot in Baishanzu, Zhejiang Province, with the aim to explore the soil factors that affected the diversity of tree and microbial communities under varying soil moisture conditions.Additionally, a correlation was also conducted to examine the relationship between tree diversity and soil microbial diversity.The results indicated that soil moisture had a significant impact on soil physicochemical properties.Under low moisture conditions, soil organic carbon, available potassium, available phosphorus, total phosphorus, total nitrogen, nitrate nitrogen and ammonium nitrogen contents were significantly lower than under high moisture conditions, while soil pH values were significantly higher than under high moisture conditions.High soil moisture significantly enhanced the diversity of bacterial community while concurrently reducing that of fungal community.These changes were accompanied by notable alterations in the relative abundances of the majority of bacterial and fungal phyla.The diversity of soil microbial and tree communities, as well as the relative abundance of soil microbes, exhibited significant differential responses to soil physicochemical properties under different moisture conditions.The Simpson diversity index of soil fungal community was significantly positively correlated with that of tree community under different moisture conditions.For the bacterial community, its Simpson diversity index was only significantly positively correlated with that of tree community under low moisture conditions.In conclusion, the soil physicochemical properties have a significant impact on the communities of soil microbes and tree species in the Baishanzu forest, and this process is regulated by soil moisture.Research results provide insights into the impacts of climate change, such as drought, on subtropical forest ecosystems and the protection of forest ecosystems in this region.