Study On Variation In Ecosystem Multifunctionality Driven By Plant Diversity And Environmental Factors In Inner Mongolia Grassland

Global climate and land use changes have induced serious biodiversity loss,which has inspired considerable research on the relationship between biodiversity and ecosystem functioning(BEF).Most early BEF studies focus on the relationship between taxonomic diversity index(e.g.,species richness)and one or a few ecosystem functions(e.g.,plant productivity,nutrient cycling),and only the potential effects of environmental factors are considered.With the increasing understanding of the importance of ecosystem multifunctionality(EMF),the current research has focused on the relationship between biodiversity and ecosystem multifunctionality(BEMF).Most of BEMF studies were done using manipulation experiments,while the influence of environmental factors on BEMF in natural ecosystems at a regional scale was largely unexplored.In this study,the interrelationships between species diversity(SR),functional traits(CWMs)and functional diversity(FD),and ecosystem multifunctionality as well as abiotic factors were explored along a gradient of climatic aridity in Inner Mongolia grassland.The main results were as follows:1.Diversity and ecosystem multifunctionality tended to decrease simultaneously in association with the increase of climatic aridity from the southwest to the northeast in Inner Mongolia grassland.2.The relationships between biodiversity indices and EMF were weak when the control of environmental factors were analyzed.Climate is the most important impacting factor,while soil has only a weak effect on ecosystem multifunctionality.3.The abiotic and biotic factors jointly accounted for 66.4% of the variation in EMF on the climate gradient,and 40.4% of the variation could be explained by biotic factors only,whereas 64.7% could be explained by climate and soil factors only including climate and soil characteristics.The climate and soil factors showed a predominant effect on EMF.4.Climate aridity had direct effects on EMF,and also indirect effects via altering soil properties.Biodiversity had no direct effect on EMF.Our results deepen a full understanding of the effects of environmental factors on BEMF relationships,and the roles of biotic and abiotic factors in determining EMF along an environmental gradient at a regional scale,which is of great significance for devising strategies in biodiversity conservation and maintenance of ecosystem functioning.