巢湖入湖河道岸坡鸟类多样性及其影响因素

Bird diversity and its affecting factors on the riverbanks of main rivers entering Chao Lake

河道岸坡是河道生态系统的重要组成部分,也是野生动物的重要生境。鸟类是河道岸坡的常见动物类群,其群落组成受河道岸坡生境因子的影响。于2021年8月至2022年7月,以巢湖周边5条河道为研究对象,根据河道岸坡特征,选取3类岸坡,共设置45条样线,对河道岸坡鸟类的种类、数量分布,与距道路距离、岸坡宽度、岸坡坡度以及乔木、灌木、草本植物盖度和平均高度等生境因子进行调查,探讨具有不同结构的河道岸坡对鸟类多样性的影响,采用多元逐步回归分析探究鸟类多样性与生境因子的关系。结果表明,3类岸坡中共有鸟类14目44科116种,其中水鸟36种,国家重点保护野生鸟类11种,安徽省重点保护鸟类35种,IUCN濒危物种红色名录中的极危(CR)物种1种。与其他两类岸坡生境相比,人工型岸坡对鸟类多样性影响最大,而自然原型岸坡更有利于提高鸟类生物多样性。另外,草本植物盖度及平均高度、岸坡坡度和岸坡宽度对鸟类多样性具有显著影响。其中,宽度大的缓坡自然原型岸坡鸟类物种丰富度最高,表明鸟类岸坡生境选择偏向于平缓的自然型岸坡生境。本研究结果可为巢湖河道岸坡建设、管理和生物多样性保护提供科学依据与技术支持。

Riverbanks are important components of riverine ecosystems and provide important habitats for wildlife.Birds are common animals on riverbanks,the community composition of which is influenced by local habitat factors.From August 2021 to July 2022,a total of 45 line transects were established on three types of riverbanks of five rivers entering Chao Lake.We investigated the distribution and populations of bird species on the riverbanks in terms of the distance from the road,bank width,slope gradient,and the cover and average height of trees,shrubs,and herbs.Furthermore,we examined the effects of different riverbank structures on bird diversity.The relationship between bird diversity and habitat factors was quantified using multiple stepwise regression analysis.The results showed that 116 species of birds(14 orders and 44 families)were recorded across the three types of banks,including 36 species of waterbirds,11 species of nationallevel protected birds,35 species locally protected by Anhui Province,and one critically endangered(CR)species in the IUCN Red List of Threatened Species.Compared with other types of bank habitats,the artificial bank had the greatest impact on bird diversity,and the natural bank was more conducive to maintaining bird diversity.Herbaceous plant cover and its average height,bank slope gradient,and bank width significantly affected bird diversity.The highest bird species richness was observed on the bank with natural wide slopes,indicating that birds favored gentle natural bank habitats.Our results can provide a scientific basis and technical support for the construction,management,and biodiversity conservation of the riverbanks around Chao Lake.