云南省横断山区小型兽类的组成及空间分布

目的 了解和阐述我国西南横断山区小型兽类的组成及其空间分布状况.方法 在既往系列区系调查研究的基础上,就云南省西部横断山区北纬21°～29°(计8个纬度梯度带,分别以Ⅰ～Ⅷ表示),海拔100～5000m(分9个海拔梯度带,分别以A～I表示)之间所知分布小型兽类的组成及其空间分布的资料进行综合整理、统计.结果 发现云南省横断山区小型兽类由5目11科58属187种(亚种)组成.小型兽类科、属、种丰富度沿纬度梯度带分布的主要情况是:Ⅰ带9科30属44种;Ⅱ带9科33属57种;Ⅲ带9科38属74种;Ⅳ带9科43属93种;Ⅴ带10科43属101种;Ⅵ带9科39属91种;Ⅶ带11科40属102种;Ⅷ带11科35属67种;种和属丰富度基本呈现随纬度增加逐步增高后降低的分布格局,高峰值主要出现在中纬度高度24°N～27°N区间;它们沿海拔梯度带分布的主要情况是:A带8科28属54种;B带9科41属90种;C带9科37属102种;D带10科41属101种;E带9科35属94种;F带9科33属76种;G带9科29属58种;H带8科15属28种;1带4科属7种,种和属丰富度总体上呈现中间高、两头低的空间分布格局,高峰值主要出现在中海拔高度1500～3000m区间.结论 横断山区小型兽类沿各纬度和海拔梯度的组成和分布情况不同,但总体呈现出以中海拔和中纬度梯度带物种丰富度都相对较高的空间分布特征.

The composition and spatial distribution of small mammals in the Hengduan Mountains of Yunnan,China

Objective To present the composition and spatial distribution patterns of small mammals in Hengduan Mountains, a mountainous area in the southwest of China. Methods Based on previous serial investigations of small mammal fauna, the data of the composition and spatial distribution of small mammals were collected and statistically analyzed. The investigated areas covered from north latitude 21° up to 29°, including eight latitude zones which were denoted as I -VIII and altitude from 100 to 5000 meters, including nine altitude zones denoted as A-I, in Hengduan Mountains （west of Yunnan province）. Results The small mammals identified were composed of 187 species （subspecies）, 58 genera, 11 families, 5 orders in Heugduan Mountains of Yunnan. The richness distributions of small mammals in species, genera and families along the latitudinal gradient revealed that there were 44 species, 30 genera, 9 families in zone I ; 57 species, 33 genera, 9 families in zone II ; 74 species, 38 genera, 9 families in zone III; 93 species, 43 genera, 9 families in zone IV; 101 species, 43 genera, 10 families, in zone V; 91 species, 39 genera, 9 families in zone VI; 102 species, 40 genera, 11 families in zone VII; 67 species, 35 genera, 11 families in zone VIII. A gradual increase followed by a gradual decrease was noticed in the species and genera richness distribution as the latitude increased, the peak at 24° N-27° N（the mid-latitude zone）. The richness distributions along the altitudinal gradient showed 54 species, 28 genera, 8 families in zone A; 90 species, 41 genera, 9 families in zone B; 102 species, 37 genera, 9 families, in zone C; I01 species, 41 genera, 10 families in zone D; 94 species, 35 genera, 9 families in zone E; 76 species, 33 genera, 9 families in zone F; 58 species, 29 genera, 9 families in zone G; 28 species, 15 genera, 8 families in zone H; 7 species, 5 genera, 4 families in zone I. A U-shaped pattern could be observed in the species and genera richness distribution, with the peak at about 1500-3000 m （midaltitude zone）. Conclusion Varying composition and distribution of small mammals were observed at different latitude and altitude zones in Hengduan Mountains, with relatively greater species richness seen at the mid-latitude and mid-altitude zones.