Effects of different functional structure parameters of plant communities on slope runoff in different periods of the year in semiarid grasslands

Research on sustainable use of water resources is needed to ensure food security, limit erosion, and prevent land degradation. Owing to the importance of water conservation to ecosystems, further research on the water conservation functions of different ecosystems is needed. Given the influence on water conservation functions, it is critical to identify environmental factors mediating slope runoff. In this study, the focal study area was the Yangjuangou catchment (36°42' N, 109°31' E) of the Loess Plateau in Shaanxi Province, China. Using a trait-based approach, a quantitative analysis was conducted to research effects of the functional structure parameters of plant communities on runoff of grass slopes for different periods of the year under differing rainfall intensity conditions. Results show that in mid-June, which represents the start of the growing season, effects of root traits on slope runoff decrease with increasing rainfall intensity. Slope runoff was found to be mainly affected by various plant functional traits in late July and aboveground parts of plants in early September. Given that few studies have focused on runoff processes using a trait-based approach at the community scale, this research can serve as a new reference for investigating the relationship between slope runoff and vegetation.