Community characteristics of wintering waterbirds and their responses to environmental factors in the Yunling Lake Group, Yunnan Province

Waterbirds are crucial components and indicator taxa of lake wetland ecosystems. Understanding the relationships between waterbirds and lake environments holds significant implications for lake management and conservation. This study selected five plateau lakes (Cibi Lake, Erhai Lake, Eryuan West Lake, Jianhu Lake, and Lashihai Wetland) in the Yunling Mountain area of Yunnan Province as the research regions. Waterbird surveys were conducted in these lakes during the wintering periods of 2019 and 2021. Redundancy Analysis (RDA) and correlation analysis were employed to explore the relationships between waterbird diversity and lake environmental factors.The survey results showed that 29 waterbird species belonging to 6 orders and 6 families were recorded in Cibi Lake, with 1 dominant species. Erhai Lake had 41 species categorized into 8 orders and 11 families, including 2 dominant species. Eryuan West Lake documented 36 species from 7 orders and 9 families, with 3 dominant species. Jianhu Lake boasted the highest number of waterbird species (48), which were grouped into 9 orders and 13 families, encompassing 5 dominant species. Lashihai Wetland recorded 37 species belonging to 7 orders and 10 families, with 2 dominant species.Among all the lakes, Erhai Lake exhibited the highest waterbird species richness, with a richness index of 54.94±2.44, followed by Jianhu Lake (37.41±1.77), Lashihai Wetland (25.06±3.48), Cibi Lake (22.57±0.87), and Eryuan West Lake (21.3±3.07). The Shannon-Wiener diversity index and Pielou evenness index displayed a consistent pattern: both were the highest in Jianhu Lake, followed by Eryuan West Lake, Lashihai Wetland, Erhai Lake, and Cibi Lake in descending order. Lakes with higher diversity levels also featured more uniform species composition.Regarding the similarity of waterbird communities, the average similarity index was 0.25. The highest similarity was observed between Cibi Lake and Eryuan West Lake (Sorensen index: 0.35), while the lowest was between Erhai Lake and Lashihai Wetland (Sorensen index: 0.15). Across all lakes, waterbirds of the Rallidae family accounted for the largest number of individuals, making up 59.21% of the total surveyed population. Except for Cibi Lake, waterbirds from Rallidae and Anatidae were the main dominant species in the other lakes, whereas the dominant species in Cibi Lake were from Rallidae and Podicipedidae.Correlation analysis of environmental factors indicated that lake area and monthly average temperature were the primary factors affecting waterbird species richness, while water turbidity and altitude significantly influenced waterbird diversity indices and evenness indices. In conclusion, there were significant differences in waterbird community characteristics among the lakes in the Yunling Lake Group. Lake area and water turbidity played key driving roles in the distribution, abundance, and diversity of waterbird communities. The results of this study can provide a scientific basis for the protection and ecological management of waterbird resources in the plateau lake wetlands of the Yunling Mountains.