Abstract
The primary goal of wetland restoration is to understand the species assembly process in order to strategically guide community development. Providing suitable habitats for waterbirds is one of the key objectives. In recent years, Chaohu Lake-a typical gate-controlled reservoir lake in the middle and lower Yangtze River floodplain-has faced wetland habitat homogenization due to sustained high- water- levels. This has made the maintenance of regional waterbird metacommunity diversity a critical concern. This study employed a trait-based approach, using Linear Mixed Models (LMMs) and Generalized Dissimilarity Modeling (GDM), to quantify the impacts of lakeshore wetland restoration (2020-2023) on wintering waterbird functional diversity. Results showed significant enhancements in functional α-diversity within restored wetlands (FRic, FDis, and FDiv, p < 0.01), highlighting the importance of habitat heterogeneity. Notably, restored wetlands exhibited coupled patterns of higher functional β-diversity turnover rates and lower functional nestedness over time, forming distinctive species assemblages. Environmental filtering was primarily driven by trait loss mechanisms, with water depth and aquatic vegetation coverage identified as key drivers. In conclusion, wetland restoration significantly enhanced the functional diversity of wintering waterbirds in Chaohu Lake, emphasizing the critical role of functional diversity in evaluating restoration effectiveness for high- water- level gate-controlled floodplain lakes.