中国翼手目地理分布的环境因子影响分析

Analysis of environmental factors on geographical distribution of Chinese chiroptera

利用地理信息系统提取了中国翼手目90个物种已知地理分布点的环境因子数据,并利用主成分分析和逐步回归分析研究了这些环境因子对中国翼手目动物地理分布和种数密度分布的影响程度。结果表明,按其影响程度大小,影响中国翼手目动物地理分布的连续型环境因子依次为年平均气温、大于零度日数、一月份平均气温、无霜期日数、年降雨量、年平均相对湿度、七月份平均气温、海拔高度和年日照时数,其中年日照时数和海拔高度为负影响;影响翼手目种数密度分布的决定环境因子是年降雨量,但年平均气温也有明显作用。作者认为,气候因子影响翼手目动物地理分布的机制是限制性因子的作用,主要受冬眠和活动及摄食时间长短的限制,而种数密度分布则决定于环境资源的丰富度,即主要受到由降雨量决定的食物种类多少的影响。另外,对类别环境因子的研究表明:植被类型对翼手目的种数分布没有明显影响;具有多洞穴特点的喀斯特和火山熔岩地貌具有较多的翼手目种类,但红层地貌由于分布于南方和分散分布的特点而具有最高的翼手目种数密度[动物学报51(3):413-422,2005]。

We extracted data about environmental factors of 90 Chinese Chiroptera species at known distribution points by using GIS,and conducted PCA and stepwise regression analyses to evaluate impacts of these environmental factors on geographical distribution and species density of Chinese Chiroptera.Our results show that impacts of these environmental factors on geographical distributions of Chinese Chiroptera are in order of annual average temperature,days of temperature above zero degree,January average temperature,days of annual frostless season,annual rainfall,annual average relative humidity,July average temperature,altitude,and annual sunshine hours;however,annual sunshine hours and altitude are of negative impact.Annual rainfall is the determining environmental factor on Chinese Chiroptera species density distribution,and annual average temperature also has relatively significant affect.The authors suggest that geographical distribution of Chiroptera is limited by climate factors mainly related to winter hibernation and daily duration for activity and feeding,but species density distribution is decided by resources abundance of food items which are usually related to rainfall.In addition,our results also imply that vegetation types do not distinctly influence species density distribution of Chiroptera;although more Chiroptera species distribute Karst and Volcano lava physiognomies reasonably due to caves for inhabiting,red beds have highest species density of Chiroptera,perhaps seasonably due to its southern distribution and patched dispersion.