Research Center for Endangered Species, National Institute of Ecology, Yeongyang, South Korea.
National Migratory Birds Center, National Institute of Biological Resources, Ongjin, South Korea.
PeerJ. 2022 Apr 29;10:e13258. doi: 10.7717/peerj.13258. eCollection 2022.
The latitudinal and elevational patterns of species richness of resident and migrant birds have been of interest to researchers over the past few decades, and various hypotheses have been proposed to explain the factors that may affect these patterns. This study aimed to shed light on the elevational distribution patterns of resident and migrant bird species richness by examining biotic and abiotic factors such as climate, and habitat heterogeneity using a piecewise structural equation model (pSEM). The overall pattern of resident species richness showed a decreasing trend with increasing elevation, whereas that of migrant species richness showed an increasing trend. The mid-peak pattern of species richness was affected by a combination of resident and migrant species and not by either resident or migrant species. Our results showed that resident species were distributed in lower elevation regions with higher mean spring temperatures, whereas migrant species were found in higher elevation regions with lower mean spring temperatures and higher overstory vegetation coverage. Although high elevation conditions might adversely affect the reproduction of migrant birds, higher overstory vegetation coverage at high elevations seemed to compensate for this by providing a better nesting and roosting environment. Despite the significance of habitat diversity and understory vegetation coverage in univariate linear regression models, multiple regression models of the interconnection of ecological processes demonstrated that mean spring temperature and overstory vegetation coverage were more explanatory than other variables.
在过去的几十年里，居住鸟类和迁徙鸟类的物种丰富度的纬度和海拔分布模式一直是研究人员关注的焦点，提出了各种假说来解释可能影响这些模式的因素。本研究旨在通过使用分段结构方程模型（pSEM）检查气候和生境异质性等生物和非生物因素，阐明居住鸟类和迁徙鸟类物种丰富度的海拔分布模式。居住鸟类物种丰富度的总体模式随着海拔的升高而呈下降趋势，而迁徙鸟类物种丰富度的模式则呈上升趋势。物种丰富度的中峰模式受到居住和迁徙物种的共同影响，而不是仅受到居住或迁徙物种的影响。我们的研究结果表明，居住鸟类分布在海拔较低、春季平均温度较高的地区，而迁徙鸟类则分布在海拔较高、春季平均温度较低、上层植被覆盖度较高的地区。尽管高海拔条件可能会对迁徙鸟类的繁殖产生不利影响，但高海拔地区上层植被覆盖度较高，似乎为其提供了更好的筑巢和栖息环境，从而弥补了这一不利影响。尽管生境多样性和下层植被覆盖度在单变量线性回归模型中具有重要意义，但生态过程相互联系的多元回归模型表明，春季平均温度和上层植被覆盖度比其他变量更具解释力。
