The responses of riparian plant communities to environmental and spatial factors in the upper Han River basin, China

Abstract

Exploring the relative roles of environmental and spatial factors in shaping community composition is crucial to gain insights into community assembly. At present, however, their roles in riparian plant communities remain to be fully elucidated. Here, we investigated the responses of taxonomic and functional trait compositions of riparian plant communities to environmental and spatial factors in the upper Han River basin, China. We aimed to (1) investigate the responses of both taxonomic composition and functional traits to anthropogenic disturbances and (2) compare the relative roles of environmental and spatial factors in affecting both taxonomic and functional trait compositions. Results showed that species diversity of riparian plant communities was highest under mild disturbance, and both types of riparian plant community composition were strongly influenced by anthropogenic activities. In addition, the riparian plant community compositions in the upper Han River basin were driven by both environmental and spatial factors. Compared to spatial factors, environmental filtering was more important in explaining species composition, while the opposite trend was observed for functional composition due to the high environmental heterogeneity of the 5 tributaries and the reproductive mode from riparian plants. Thus, for assessment and management of riparian vegetation, the taxonomic and functional characteristics of communities should be considered as they may respond to important drivers and anthropogenic disturbances differently.