Topsoil microbial community structure responds to land cover type and environmental zone in the Western Pacific...

Soil encompasses diverse microbial communities that are essential for fundamental ecosystem functions such as biogeochemical cycling. To better understand underlying biogeochemical processes, it is necessary to know the structure of soil archaeal and bacterial communities and their responses to edaphic and climate variables within and across various land cover types (LCTs) and environmental zones (ENZs). Here we sampled eighty-nine sites across five ENZs and four LCTs within the Western Pacific region. Through leveraging the second-generation sequencing of topsoil samples, we showed that α-diversity (taxonomic diversity) of archaea strongly varied within LCTs, whereas bacterial α-diversity was significantly controlled by both LCT and ENZ. Soil archaea and bacteria showed global niche differentiation associated with contrasting diversity responses to latitude and differential responses of microbial diversity patterns to edaphic and climate variables within LCTs and ENZs. In contrast to α-diversity, microbial β-diversity (the compositional dissimilarity between sites) was majorly governed by ENZs, particularly for archaea (P < 0.01). Our results highlight the importance of LCTs and ENZs for understanding soil microbial contributions to nutrient dynamics and ecosystem resilience under land-use intensification and climate change.