Shifting spatiotemporal heterogeneity of precipitation patterns profoundly affects ecosystem stability. In arid regions with sparse higher plant cover, biological soil crusts (Biocrusts), dominated by desert cyanobacteria as keystone species, drive critical ecological functions such as carbon-nitrogen cycling and soil-water conservation through microbial community dynamics. 

Traditional research has largely focused on the effects of single annual mean precipitation (MAP) on ecosystems, often overlooking the multifaceted characteristics of precipitation patterns (e.g., variability and frequency) and their cascade effects mediated by microbial communities. 

In a study published in Global Ecology and Biogeography, a research team led by Prof. HU Chunxiang from the Institute of Hydrobiology of the Chinese Academy of Sciences systematically analyzed 38 years of daily precipitation records alongside multitrophic microbial community characteristics of the arid regions of northwestern China, and revealed the cascade mechanism through which multifaceted precipitation traits regulate biocrust multifunctionality via microbial diversity.

By analyzing historical precipitation data, researchers discovered that precipitation variability exhibited stronger explanatory power for biocrust multifunctionality than MAP. High precipitation variability was associated with reduced relative abundances of key functional taxa in soil microbial communities, and promoted the aggregation of species with low functional importance. This finding highlights the limitations of traditional MAP-based climate-response models, and underscores the potential threats of extreme precipitation fluctuations to arid-region ecosystems.

Furthermore, researchers dissected the contribution patterns of microorganisms across trophic levels to multifunctionality. Heterotrophic bacteria and fungi primarily maintained local-scale functionality via species richness, whereas photoautotrophic cyanobacteria drove functional stability through phylogenetic diversity. This finding suggests that functional-group-specific diversity analyses can more accurately capture microbial contributions to ecosystem processes.

Moreover, researchers qualified the role of microbial β-diversity in multifunctionality. They revealed that species replacement rather than richness difference across microbial communities was the core mechanism sustaining regional-scale multifunctionality differences/asynchrony (β-multifunctionality). When local functions were disrupted by precipitation fluctuations, species replacement in adjacent areas maintained overall ecosystem stability through functional complementarity. This finding provides a new perspective on the spatial resilience of desert ecosystems.

Through structural equation modeling, a cascading process was identified where the indirect effect of precipitation heterogeneity, regulated by microbial β-diversity, accounted for a higher proportion of variance in β-multifunctionality than direct climate influence. This indicated that regulating soil microbial community structure through inoculation and other methods may effectively buffer the impact of climate change on arid ecosystems.

This study elucidates the limitations of single-dimensional climate-response research by constructing a cascade framework of "multifaceted precipitation patterns-microbial diversity-ecosystem functions." It suggests that it is critical to prioritize cyanobacterial strains with distinct phylogenetic profiles during artificial biocrust cultivation to enhance functional stability, and to implement long-term monitoring of precipitation variability effects in climate-sensitive regions.