1. Biodiversity and ecosystem multifunctionality are currently hot topics in ecological research. However, little is known about the role of multitrophic diversity in regulating various ecosystem functions, which limits our ability to predict the impact of biodiversity loss on human well–being and ecosystem multifunctionality. 2. In this study, multitrophic diversity was divided into three categories: plant, animal, and microbial communities (i.e., plant diversity, rodent diversity, bacterial and fungal diversity). Also, 15 ecosystem functions were divided into four categories–water conservation, soil fertility, nutrient cycling and transformation, and community production–to evaluate the significance of biotic and abiotic variables in maintaining ecosystem multifunctionality. 3. Results indicated that species diversity at multiple trophic levels had a greater positive impact on ecosystem multifunctionality than species diversity at a single trophic level. Notably, the specific nature of this relationship depended on the niche breadths of plants, indicating that plants were key indicators linking above and below ground trophic levels. Abiotic factors such as altitude and pH directly acted on ecosystem multifunctionality and could explain changes in ecosystem functions. 4. Overall, our study offers valuable insights into the critical role of multitrophic species diversity in preserving ecosystem multifunctionality within alpine grassland communities, as well as strong support for the importance of biodiversity protection.

We conducted a comprehensive investigation of the interrelationships among the species diversity, productivity, community structure, and soil nutrients of vegetation communities of an alpine meadow ecosystem on the eastern Qinghai–Tibet Plateau. We performed biodiversity manipulation experiments to examine the effects of removing plant functional groups (Gramineae, Cyperaceae, Legumes, and other Forbs) for 3 and 10 years at a research station in Haibei. Interannual variation in the species richness and above- and belowground biomass of the community gradually decreased over time. Species richness and productivity were positively correlated, and this correlation became increasingly significant over time. Removal of the plant functional groups resulted in fewer Gramineae species within the community. However, soil total nitrogen, phosphorus, organic matter, and moisture contents increased significantly in the Legume removal treatment. The removal of other Forbs led to the lowest negative cohesion values, suggesting that this community may have had difficulty recovering its previous equilibrium state within a short period of time. The effects of species removal on the ecosystem were likely influenced by the species structure and composition within the community. Changes in the number of Gramineae species indicated that they were more sensitive and less resistant to plant functional group removal. Legume removal may also have indirectly caused distinct community responses through starvation and compensation effects. In summary, species loss at the community level led to extensive species niche shifts, which caused community resource redistribution and significant changes in community structure.

In the Alpine Meadow ecosystems of eastern Qinghai-Tibet Plateau, the interrelations among the species diversity of different vegetation communities, productivity, community structure as well as soil nutrients were thoroughly researched through running biodiversity manipulation experiment to explore the species survey consequences of 3 and 10 years of plant functional groups (Gramineae, Cyperaceae, Legumes, and other Forbs) removal at Haibei station. The results demonstrated that the interannual variation of the remaining species richness, above-ground and below-ground biomass of the community gradually presented a tendency to decrease as the removal time increased, and there was a positive relationship between species richness and productivity, and the correlation became increasingly significant. The removal behavior reduced the number of Gramineae within the remaining community. The content of soil total nitrogen, phosphorus, organic matter and moisture content of Legumes loss treatment increased significantly. The treatment that removal Forb had the lowest negative cohesion values, revealing that it is difficulty for this community to recover to the previous equilibrium state in a short time. In our study, all affects of species removal on ecosystem may be related to variance in the structure and composition of species in community. Meanwhile, changes in the number of Gramineae indicated that Gramineae are more sensitive and less resistant to removal behavior. Furthermore, the specific performance of Legumes removal indirectly indicates that the loss of diverse plant function groups prompted distinct replies to the starvation and compensation effects. In a nutshell, species loss at the community level leads to shifts in the niche of each species, inducing a redistribution of community resources and leading to significant changes in community structure.