The Effect Of Dasiphora Fruticosa On Soil Microbes And Ecosystem Functions In The Subalpine Meadow

High-altitude ecosystems of the Tibetan Plateau are undergoing significant global changes that may alter the range of shrub.The occurrence of shrubs in subalpine meadow is commonly thought to alleviating environmental stresses and supporting higher biodiversity which may have important consequences for ecosystem functions.However,few studies have assessed how the effect of shrub on soil microbes and ecosystem functions vary with seasons and elevations.To explore the effect of the subalpine shrub D.fruticosa on soil microbial(α andβ)diversity and ecosystem functions(multifunctionality and turnover of functions)varying with seasons and elevations,we conducted a study in the subalpine meadow of the Tibetan Plateau.Five sites were selected along an elevation gradient in three seasons(i.e.,summer,autumn and winter).Two scientific questions were mainly addressed:(1)How do season,elevation and shrub interactively affect the α-diversity of soil microbes(bacteria,fungi)and ecosystem multifunctionality?(2)How do season,elevation and shrub interactively affect the β-diversity of soil microbes(bacteria,fungi)and turnover of ecosystem functions?The results of the study showed that(1)the shrub increased soil microbial richness both during the cold season and at high elevations,which was associated with changes in temperature,multiple soil environmental indicators,and plant variables.The shrub also reduced the difference in soil microbial richness between seasons,indicating that the presence of shrubs could provide a relatively stable environment for soil microbial α-diversity.Further,we found that the shrub improved ecosystem multifunctionality by increasing soil microbial α-diversity.(2)Although the effect of shrub on soil microbial β-diversity was not as strong as those of season and elevation,it also increased soil microbial β-diversity and moderated the effects of season and elevation on soil microbial β-diversity,which were mainly related to changes in temperature,soil water content,soil p H and herbaceous plant biomass.Further analysis revealed that the shrub improved the turnover of functions by increasing soil microbial β-diversity.Our study shows that the shrub can alter seasonal and elevational effects on soil microbial diversity in subalpine meadows,and that such effects are further translated to ecosystem functions.This result highlights the important role of dominant species in maintaining soil biodiversity and ecosystem functions in subalpine meadows and emphasizes the importance to focus on spatial and temporal changes in abovebelowground linkages.This study also provides a scientific basis for the conservation of subalpine meadow ecosystem diversity,multifunctionality maintenance,and sustainable use management by exploring the mechanism of shrub effect on soil microbial communities and ecosystem functions that vary with seasons and elevations.