Climate and soil nutrients generate distinct diversity patterns across four elevational gradients within the same region

Abstract

Numerous researchers have endeavored to discover a general explanation for elevational diversity gradients, but we remain unclear whether similar diversity patterns and driving factors exist for the same life-forms along different elevational gradients within the same region. In the Ili Valley of the Central Asia Biodiversity Hotspot, we selected four elevational gradients with similar species pools and evolutionary histories to assess the factors influencing of elevational diversity pattern. Our findings indicate distinct patterns of species diversity for the same life-forms along the four elevational gradients within the same region. The species richness and abundance of woody plants are primarily controlled by climate-based factors (i.e., minimum temperature, temperature seasonality, mean annual precipitation, and potential evapotranspiration) along four elevational diversity gradients in the Ili Valley, while the species richness and abundance of herbaceous plants are primarily influenced by both climate and soil nutrients (i.e., soil organic carbon). In conclusion, climate is an important driver of species diversity for woody plants, and that the driving mechanisms of herbaceous plant diversity along elevational gradients should consider both climate and soil nutrients.