Elevational diversity gradients across seed plant taxonomic levels in the Lancang River Nature Reserve: role of temperature, water and the mid-domain effect

Abstract

It remains unclear whether the elevational diversity gradients observed in seed plants across different taxonomic levels (family, genus, and species) are driven by the same macro-environmental variables. In this study, seed plant elevational distribution data from the Lancang River Nature Reserve (Yunnan, China) were used to investigate spatial patterns in diversity and their environmental correlates, comparing across taxonomic levels. Environmental variables included energy availability, climate seasonality and environmental heterogeneity. All taxonomic levels (family, genus, and species) were found to have strong elevational richness gradients, with the strength of the gradient weakening at higher taxonomic levels. Spatial patterns in richness were explained by a combination of contemporary environmental variables and the mid-domain effect at all taxonomic levels. The independent effects of temperature- and precipitation-related variables were similar in explaining geographical patterns of family, genus and species richness. Energy, seasonality and heterogeneity variables influenced seed plant spatial richness at different taxonomic levels in similar ways.