Inconsistent elevational patterns of soil microbial biomass, diversity, and community structure on four elevational transects from subtropical forests

The use of elevational gradients as proxies for time in predicting soil microbial responses to imminent climate changes is common, yet reliance on single-transect studies has raised concerns about the method's validity due to the lack of replication. Addressing this gap, our study evaluates the effects of elevation on soil microbial communities within subtropical forests, using four closely situated transects with consistent climatic and vegetative characteristics. Through phospholipid fatty acid analysis and Illumina MiSeq sequencing, we investigate variations in microbial biomass and the composition of communities at different elevations. Our results show that the ways microbial communities, both bacteria and fungi, respond to changes in elevation, particularly in aspects of biomass and diversity, vary significantly across different transects. Environmental factors, like soil pH, soil organic carbon concentration, and climatic factors, distinctly affect the attributes of these microbial communities through diverse mechanisms. These results underscore the need for multi-transect studies to accurately measure soil microbial responses to elevation and climate changes, challenging the predictive reliability of studies based on a single transect.