菜子湖冬季水鸟空间分布与环境因子的关系研究

水鸟空间分布与环境因子的关系是生态研究的重要内容, 环境因子的变化可以通过改变栖息地的生境特征、食物资源从而直接或间接影响水鸟的种类、数量和分布。利用网格单元对2019-2020年菜子湖冬季水鸟及其环境因子进行调查, 共记录到水鸟6目12科41种, 其优势种为豆雁(Anser fabalis)和黑腹滨鹬(Calidris alpina)。运用空间自相关和多元逐步回归分析, 研究冬季水鸟的空间分布特征, 并确定影响不同取食集团水鸟分布的主要环境因子。网格鸟类占比显示, 菜子湖冬季水鸟主要分布在堂屋(30.98%)、梅花大圩(10.53%)、季庄(7.87%)、车富岛(6.49%)以及双兴村(5.67%); 食苔草水鸟与食块茎水鸟呈现显著的空间自相关, 聚集分布(P<0.05, I>0); 食鱼水鸟、食无脊椎水鸟和食种子水鸟为随机分布(P>0.05)。环境因子对不同取食集团水鸟的影响也有所差异, 食鱼水鸟会倾向于选择大面积的开阔水域, 湿地裸露出的泥滩会吸引食无脊椎水鸟在此栖息, 沉水植被的退化使得食块茎水鸟聚集分布在农田和草滩中, 广阔草滩的形成使得食苔草水鸟数量明显增加, 食种子水鸟往往分布在植被量低且水域开阔的生境中; 到居民点距离或到道路距离对食块茎水鸟、食苔草水鸟、食种子水鸟和食鱼水鸟均产生显著性影响(P<0.05)。因此, 在菜子湖湿地保护和管理时应考虑环境因子对不同取食集团越冬水鸟影响的差异。

Relationship between environmental factors and spatial distribution of wintering waterbirds at Caizi Lake,China

It is an important content of ecological research to study the relationship between the spatial distribution of waterbirds and environmental factors.Variations in environmental factors can directly or indirectly affect the species,abundance and distribution of waterbirds by changing habitat characteristics and food resources.In this study,we investigated the wintering waterbirds and environmental factors at Caizi Lake in China using grid cells,in the winter of 2019-2020.A total of 41 waterbirds species belonging to 6 orders of 12 families were counted during the surveys,and the dominant species were bean geese(Anser fabalis)and dunlin(Calidris alpina).Spatial autocorrelation and multiple stepwise regression analyses were used to study the spatial distribution patterns of wintering waterbirds and determine the main environmental factors affecting their distribution in different foraging groups.The percentage of individuals of grid birds results showed that the wintering waterbirds at Caizi Lake were mainly distributed in Tangwu(30.98%),Meihuadawei(10.53%),Jizhuang(7.87%),Chefu Island(6.49%)and Shuangxing Village(5.67%).The distribution patterns of tuber-eating waterbirds and sedge-eating waterbirds revealed significantly positive autocorrelations and clustered distributions (P<0.05, I>0), while those of seed-eating waterbirds, invertebrate-eating waterbirds and fish-eating waterbirds showed non-autocorrelational and random distributions (P>0.05). Environmental factors had differing effects on different waterbird foraging groups. Fish-eating waterbirds tended to choose the open water which has large areas, while the mudflats exposed by the wetland attracted invertebrate-eating waterbirds. The degradation of submerged vegetation led to the aggregation and distribution of tuber-eating waterbirds in farmland and grassland habitats. The quantity of sedge-eating waterbirds increased significantly because of the formation of vast grasslands. Seed-eating waterbirds were often distributed in low-vegetation and open water habitats. The distance to the nearest settlement or to the road had significant effects on tuber eaters, sedge eaters, seed eaters, and fish eaters (P<0.05). Therefore, the influence of environmental factors on different foraging groups of wintering waterbirds should be considered in the protection and management of the Caizi Lake wetland.