Soil microbial beta diversity is correlated positively with ecosystem multifunctionality of alpine meadows on the Tibetan plateau

Alpine grasslands are characterized by high environmental heterogeneity, with multiple ecological processes operating simultaneously. Capturing ecosystem functioning, therefore, requires approaches that consider several functions together rather than relying on single indicators. Ecosystem multifunctionality (EMF) provides a framework to integrate this functional diversity across spatial scales, while acknowledging that its interpretation depends on the functions considered. Generally, soil microorganisms are regarded as the main drivers of grassland EMF, but the relations between them in the alpine meadow ecosystem remain unknown. The main aim of this study was to fill this gap by examining the impacts of soil bacteria and fungi on EMF. From a field study of 90 sites across the southeastern part of the Tibetan Plateau, soil bacterial and fungal β diversities were correlated positively with EMF, and the relationships were mediated mainly by soil pH. The soil fungal, but not bacterial, community network stability also correlated positively with EMF. In addition, plant Pielou evenness and soil bacterial Shannon diversity were correlated negatively with EMF, while the Shannon diversities of soil fungi and plant species were not correlated with EMF. The current results emphasized that: 1) soil bacteria and fungi had different impacts on EMF; and 2) bacterial and fungal β diversities were important drivers of EMF in alpine meadows of the Tibetan plateau.