Tan Xinwei, Yang Xueru, Chen Chuanwu, Wang And Yanping
Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210023, China.
Curr Zool. 2020 Oct 28;67(4):383-392. doi: 10.1093/cz/zoaa069. eCollection 2021 Aug.
Nestedness is an important pattern frequently reported for species assemblages on islands or fragmented systems. However, to date, there are few studies that comprehensively investigated faunal nestedness and underlying processes in urbanized landscapes. In this study, we examined the nestedness of bird assemblages and its underlying causal mechanisms in 37 urban parks in Nanjing, China. We used the line-transect method to survey birds from April 2019 to January 2020. We used the Weighted Nestedness metric based on Overlap and Decreasing Fill (WNODF) to estimate the nestedness of bird assemblages. We applied spearman partial correlation test to examine the relationships between nestedness ranks of sites and park characteristics (area, isolation, anthropogenic noise, number of habitat types, and building index), as well as between nestedness ranks of species and their ecological traits (body size, geographic range size, clutch size, minimum area requirement, dispersal ratio, and habitat specificity). We found that bird assemblages in urban parks were significantly nested. Park area, habitat diversity, building index, habitat specificity, and minimum area requirement of birds were significantly correlated with nestedness. Therefore, the nestedness of bird assemblages was caused by selective extinction, habitat nestedness, and urbanization. However, the nestedness of bird assemblages did not result from passive sampling, selective colonization, or human disturbance. Overall, to maximize the number of species preserved in our system, conservation priority should be given to parks with large area, rich habitat diversity, and less building index. From a species perspective, we should focus on species with large area requirement and high habitat specificity for their effective conservation.
嵌套性是岛屿或破碎化系统中物种组合经常报道的一种重要模式。然而，迄今为止，很少有研究全面调查城市化景观中动物区系的嵌套性及其潜在过程。在本研究中，我们调查了中国南京37个城市公园中鸟类组合的嵌套性及其潜在因果机制。我们于2019年4月至2020年1月采用样线法对鸟类进行调查。我们使用基于重叠和递减填充的加权嵌套性指标（WNODF）来估计鸟类组合的嵌套性。我们应用斯皮尔曼偏相关检验来检验样点嵌套性等级与公园特征（面积、隔离度、人为噪声、栖息地类型数量和建筑指数）之间的关系，以及物种嵌套性等级与其生态特征（体型、地理分布范围大小、窝卵数、最小面积需求、扩散率和栖息地特异性）之间的关系。我们发现城市公园中的鸟类组合具有显著的嵌套性。公园面积、栖息地多样性、建筑指数、栖息地特异性和鸟类的最小面积需求与嵌套性显著相关。因此，鸟类组合的嵌套性是由选择性灭绝、栖息地嵌套性和城市化导致的。然而，鸟类组合的嵌套性并非由被动采样、选择性定殖或人为干扰导致。总体而言，为了使我们系统中保存的物种数量最大化，保护优先级应给予面积大、栖息地多样性丰富且建筑指数低的公园。从物种角度来看，我们应关注面积需求大且栖息地特异性高的物种，以实现其有效保护。
