Abstract:

Large-scale spatial distribution patterns of biodiversity and understanding the mechanisms that form these patterns are core questions for the fields of ecology and biogeography. The Yellow River basin is an important ecological barrier in China. Therefore, understanding the distribution patterns of plant and animal richness and what influences these patterns for is important for the ecological conservation and high-quality development of the Yellow River basin. Here, we used collected data for several variables (species spatial distribution, climate, environmental heterogeneity, and human activity) to explore the spatial distribution patterns of species richness and their main influencing factors for angiosperms and terrestrial vertebrates in the Yellow River basin. We found that the species richness for angiosperms and terrestrial vertebrates had similar distribution patterns at regional scale. Species richness was highest in the southern mountain region and lowest in the eastern alpine region and the northern arid region. Tree regression models showed that the canopy height range was the most important predictor for angiosperm species richness and net primary productivity range was the most important predictor for terrestrial vertebrate species richness. When the spatial autocorrelation was removed, environmental heterogeneity and climatic factors still had important and similar explanations for species richness at regional scale. The results indicate that species richness is determined by environmental heterogeneity and climate. Human activity was not a main influencing factor for species richness pattern. For future research, choosing more accurate environmental driving factors for different regions or selecting different types of environmental heterogeneity factors for analyses will help with understanding the causes of species diversity patterns more deeply.

Key words: angiosperms, terrestrial vertebrates, spatial distribution patterns, climate, environmental heterogeneity, Yellow River basin