Relationship between biodiversity and ecosystem multifunctionality along the elevation gradient in alpine meadows on the eastern Qinghai-Tibetan plateau

Exploring the spatial pattern of biodiversity in different dimensions and its relationship with ecosystem multifunctionality was one of the hot topics in ecological research, and elevation was an important topographic factor affecting biodiversity changes. The maintenance mechanism of ecosystem multifunctionality (EMF) relationship between different dimensions of biodiversity and ecosystem multifunctionality in alpine meadows on the eastern Qinghai-Tibetan Plateau was still unclear. This paper investigates the elevation patterns of species, functions, and phylogenetic diversity of plant communities in alpine meadows on the eastern Qinghai-Tibetan Plateau and their effects on EMF using factor analysis and the radial basis function (RBF) neural network model. The results showed that (1) the species and phylogenetic diversity indices (except MPD index) increased and then decreased with elevation; the functional diversity indices FRic and FEve showed a decreasing trend with elevation, while FDiv showed the opposite. (2) Ecosystem multifunctional indices for the five elevation gradients were 3000 m > 3250 m > 3500 m > 3750 m > 4000 m. There were significant correlations between biodiversity and ecosystem functions. Species richness, Simpson, FRic, and FDiv increased with increasing EMF, but the relationship between phylogenetic diversity and EMF was insignificant. (3) Among the biodiversity indices, species richness and functional richness indices had a greater impact on EMF and were also important drivers to explain changes in EMF, followed by PD indices. The high biodiversity of alpine meadows can contribute to the supply of multifunctional ecosystems, making them healthier and more stable.