Numbers of individuals and endemicity for birds in three study sites of the Himalayas-Hengduan mountains of China

1. Describing the patterns and revealing the underlying mechanisms responsible for variations in community structure remains a central focus in ecology. However, important gaps remain, including our understanding of species abundance. Most studies on abundance-based relationships are from either temperate ecosystems or tropical ecosystems, and few have explicitly tested abundance-based relationships across a temperate to tropical ecotone. 2. Here, we use a comprehensive dataset of breeding birds across elevation spanning a temperate to subtropical gradient in the Himalayas-Hengduan mountains of China to examine the relationship between species abundance and (1) elevational range size, (2) body size, (3) elevational range center and, (4) endemicity. 3. We tested a priori predictions for abundance-elevational range size relationship, abundance-body size relationship, and abundance-elevational range center relationship and explored how these relationships change along this temperate to sub...1. 阐明群落结构（community structure）变异的模式并揭示其背后的作用机制，始终是生态学研究的核心议题。然而当前仍存在诸多重要研究空白，例如我们对物种多度（species abundance）的认知仍有不足。现有关于多度关联的研究大多仅聚焦于温带生态系统或热带生态系统，鲜有研究明确检验温带至热带生态交错带（ecotone）内的多度关联规律。 2. 本研究依托中国喜马拉雅-横断山脉区域内一套涵盖海拔梯度、覆盖温带至亚热带跨度的繁殖鸟类综合数据集，旨在检验物种多度与以下四类指标的关联：(1) 海拔分布范围大小，(2) 体型大小，(3) 海拔分布中心，以及(4) 特有性（endemicity）。 3. 我们针对多度-海拔分布范围大小关联、多度-体型大小关联以及多度-海拔分布中心关联，检验了先验假设（a priori predictions），并探讨了这些关联沿该温带至亚...的变化规律。