Liang Chenxia, Feng Gang, Si Xingfeng, Mao Lingfeng, Yang Guisheng, Svenning Jens-Christian, Yang Jie
School of Ecology and Environment Inner Mongolia University Hohhot China.
Department of Biological Sciences University of Toronto-Scarborough Toronto ON Canada.
Ecol Evol. 2017 Nov 23;8(1):53-58. doi: 10.1002/ece3.3606. eCollection 2018 Jan.
Bird species richness is mediated by local, regional, and historical factors, for example, competition, environmental heterogeneity, contemporary, and historical climate. Here, we related bird species richness with phylogenetic relatedness of bird assemblages, plant species richness, topography, contemporary climate, and glacial-interglacial climate change to investigate the relative importance of these factors. This study was conducted in Inner Mongolia, an arid and semiarid region with diverse vegetation types and strong species richness gradients. The following associated variables were included as follows: phylogenetic relatedness of bird assemblages (Net Relatedness Index, NRI), plant species richness, altitudinal range, contemporary climate (mean annual temperature and precipitation, MAT and MAP), and contemporary-Last Glacial Maximum (LGM) change in climate (change in MAT and change in MAP). Ordinary least squares linear, simultaneous autoregressive linear, and Random Forest models were used to assess the associations between these variables and bird species richness across this region. We found that bird species richness was correlated negatively with NRI and positively with plant species richness and altitudinal range, with no significant correlations with contemporary climate and glacial-interglacial climate change. The six best combinations of variables ranked by Random Forest models consistently included NRI, plant species richness, and contemporary-LGM change in MAT. Our results suggest important roles of local ecological factors in shaping the distribution of bird species richness across this semiarid region. Our findings highlight the potential importance of these local ecological factors, for example, environmental heterogeneity, habitat filtering, and biotic interactions, in biodiversity maintenance.
鸟类物种丰富度受局部、区域和历史因素的影响，例如竞争、环境异质性、当代和历史气候。在此，我们将鸟类物种丰富度与鸟类群落的系统发育相关性、植物物种丰富度、地形、当代气候以及冰期 - 间冰期气候变化相关联，以研究这些因素的相对重要性。本研究在内蒙古进行，这是一个干旱和半干旱地区，植被类型多样，物种丰富度梯度明显。纳入了以下相关变量：鸟类群落的系统发育相关性（净相关性指数，NRI）、植物物种丰富度、海拔范围、当代气候（年平均温度和降水量，MAT和MAP）以及当代 - 末次盛冰期（LGM）气候变化（MAT变化和MAP变化）。使用普通最小二乘线性模型、同步自回归线性模型和随机森林模型来评估这些变量与该地区鸟类物种丰富度之间的关联。我们发现鸟类物种丰富度与NRI呈负相关，与植物物种丰富度和海拔范围呈正相关，与当代气候和冰期 - 间冰期气候变化无显著相关性。随机森林模型排名前六的变量最佳组合始终包括NRI、植物物种丰富度和MAT的当代 - LGM变化。我们的结果表明，局部生态因素在塑造这个半干旱地区鸟类物种丰富度分布方面发挥着重要作用。我们的研究结果突出了这些局部生态因素，例如环境异质性、栖息地筛选和生物相互作用，在生物多样性维持中的潜在重要性。
