Improved understanding of the impact of vegetation on soil erosion is critical for identifying effective strategies to use in soil and water conservation. Recently, although the concept of functional identity and diversity has been applied extensively in ecology, few studies have attempted to explore the effects of functional identity and diversity on soil erosion. In this study, the plant functional traits in different periods of a season were measured, and soil erosion was monitored in runoff plots of different types of plant community in the field under actual rain events. The measured plant functional traits were extrapolated to functional identity and diversity on the plant community scale. The impacts of functional identity and diversity on soil erosion in different periods of a season and with different rainfall intensity conditions were analyzed. The results showed that in the early and middle season, functional richness and functional evenness of the plant community play an important role in reducing soil erosion during low rainfall intensity. Plant tensile strength has a great effect on soil erosion at intermediate and high rainfall intensity in the early season. However, at the intermediate and high rainfall intensity in the middle season, plant aboveground parts has the greatest effect on soil erosion. At the end of the growing season, functional divergence is the largest determinant of soil erosion form low to high rainfall intensity. This work can provide insight into the mechanism of soil erosion and provide a valuable reference for plants used in soil and water conservation.

更好地了解植被对土壤侵蚀的影响对于确定用于水土保持的有效策略至关重要。近来，尽管功能特征和多样性的概念已在生态学中得到广泛应用，但很少有研究试图探索功能特征和多样性对土壤侵蚀的影响。在这项研究中，测量了季节不同时期的植物功能性状，并在实际降雨事件下，在田间不同类型植物群落的径流图中监测了土壤侵蚀。在植物群落规模上，将所测量的植物功能性状外推至功能特性和多样性。分析了不同季节和不同降雨强度条件下功能同一性和多样性对土壤侵蚀的影响。结果表明，在早，中期，低降雨强度下植物群落的功能丰富度和功能均匀度在减少水土流失方面起着重要作用。在初期，中等强度和高降雨强度下，植物抗张强度对土壤侵蚀有很大影响。然而，在中期的降雨强度较高​​的中期，植物地上部分对土壤侵蚀的影响最大。在生长季节结束时，从低到高降雨强度，功能差异是土壤侵蚀的最大决定因素。