College of Animal Science, Xinjiang Agricultural University, No. 311, Nongda East Road, Urumqi, Xinjiang, 830052, China.
Institute of Hydrobiology of the Chinese Academy of Sciences, 7 South Donghu Road, Wuchang District, Wuhan, 430072, China.
Sci Rep. 2019 Jul 1;9(1):9453. doi: 10.1038/s41598-019-45912-7.
The analysis of the biogeographic distribution of species is the basis for establishing a strategy for land management and responding to climatic change, but research on the distribution of amphibians and reptiles in the arid land in the middle of Asia is extremely limited. After classifying the chorotypes of amphibians and reptiles in the arid land of Central Asia using a clustering analysis, we delineated their distribution characteristics and discovered the ecological determinants for the chorotypes in terms of feature selection and the Akaike information criterion (AIC). We identified 6 chorotypes at the higher level and 16 sub-chorotypes at the lower level. Compared to small-scale or subjective research, which produces unstable results, research characterized by both large scale and clustering methods yields more consistent and stable results. Our results show that the Mean Altitude (MA), Mean Annual Temperature (MAT), and Mean Temperature in the Wettest Quarter (MTWE) are the critical variables determining the higher-level chorotypes. Furthermore, geographical factors appear to have a stronger influence on chorotypes than climatic factors. Several climatic variables and MA were identified as the best fit in the AIC model at the lower level, while the sub-chorotypes are determined more by multiple climatic factors with complex relationships. The research on amphibian and reptilian distribution patterns will shed light on the overall distribution of other species in the same understudied area. Widespread species in the study area are not clearly distinguished due to the cluster analysis computing process. This problem however, appears in studies of the distribution of other organisms thus warrants further research. Our methodology based on the selection of multiple models is effective to explore how the environment determines the distributions of different animal groups.
物种的生物地理分布分析是制定土地管理策略和应对气候变化的基础，但中亚干旱地区的两栖爬行动物分布研究极为有限。我们使用聚类分析对中亚干旱地区的两栖爬行动物区系型进行了分类，描绘了它们的分布特征，并通过特征选择和 Akaike 信息准则（AIC）发现了区系型的生态决定因素。我们确定了 6 个高级区系型和 16 个低级亚区系型。与产生不稳定结果的小规模或主观研究相比，具有大规模和聚类方法特点的研究产生了更一致和稳定的结果。我们的研究结果表明，平均海拔（MA）、年平均温度（MAT）和最湿润季度的平均温度（MTWE）是决定高级区系型的关键变量。此外，地理因素对区系型的影响似乎比气候因素更强。在 AIC 模型中，有几个气候变量和 MA 被确定为低级别的最佳拟合，而亚区系型则更多地由具有复杂关系的多种气候因素决定。对两栖爬行动物分布模式的研究将为同一未充分研究地区其他物种的总体分布提供线索。由于聚类分析计算过程，研究区域内广泛分布的物种没有明显区分。然而，这种问题也出现在其他生物分布研究中，因此需要进一步研究。我们基于多种模型选择的方法对于探索环境如何决定不同动物群体的分布是有效的。
