Species richness is an important mediator of multifunctionality changes in Hobq desert shrub ecosystem.

Studying the biodiversity and multifunctionality relationships of the Hobq Desert shrub ecosystem and its response to environmental factors is crucial for ecological restoration in the region. In this study, we examined variations in biodiversity and ecosystem functioning along a precipitation gradient within the Hobq Desert shrub ecosystem. Using machine learning, we evaluated the predictive contributions of species richness and phylogenetic diversity to ecosystem multifunctionality (EMF) and applied structural equation modeling to analyze the direct and indirect impacts of biotic and environmental factors on multifunctionality. Our findings showed that species richness had a significant positive effect on EMF (p < 0.05), while phylogenetic diversity exhibited a relatively weaker influence, which was statistically non-significant (p = 0.257). Furthermore, species richness was identified as a stronger predictor of both individual ecosystem functions and EMF. Precipitation seasonality had a significant negative effect on EMF, indirectly influencing it through its impact on species richness. These findings highlight the essential role of species richness in maintaining ecosystem functioning within desert shrub ecosystems and emphasize the importance of effective biodiversity management, including both targeted conservation efforts and broad-scale ecological restoration, for preserving EMF under global climate change.