珠穆朗玛峰国家级自然保护区鸟类区系及其垂直分布特征

The fauna and vertical distribution of birds in Mount Qomolangma National Nature Reserve

珠穆朗玛峰国家级自然保护区拥有世界第一峰珠穆朗玛峰，地跨古北界和东洋界。但一直以来由于缺乏详细调查而未能掌握其区系特点，影响了对珠峰生物资源的深入认识。2010年10月―2012年10月（126 d），采用样线法在保护区全境范围内对鸟类进行了7次系统实地调查，将原有记录从227种增加至390种。区系组成中，东洋界物种数多于古北界，分别为172和113种。南北坡区系差异明显，北坡以古北种为多，共55种，占北坡物种数的71.4%；南坡以东洋种为多，共168种，占南坡物种数的56.8%。在南坡，随海拔的升高，东洋种不断减少，而古北种先增加，在4 000 m后开始减少；两者在海拔3 100~4 000 m时数量相当。据此认为珠峰地区东洋界和古北界的分界线在南坡，且位于海拔3 100~4 000 m，而不同区系物种在垂直方向上的适应是有差异的。

From October 2010 to October 2012 （total 126 days）, we used the line transect method combined with interviews applied during seven individual surveys to explore the bird resources of Qomolangma National Nature Reserve （QNNR）. Based on the historical records and the present results, a total of 390 bird species belonging to 62 families and 18 orders, had been confirmed. Our results indicated that QNNR plays a vital and unique role in bird species preservation and scientific study, especially for endemic and endangered species. Species richness of both the Palearctic and Oriental realms were different, there was no overall significant difference （164 and 178, respectively）. Species differences between the northern and southern slope of QNNR were especially remarkable. The northern slope was characterized with enriched endemic plateau species over small total number of bird species the southern flank held an abundance of bird species with complex composition. Moreover, on the southern slope, the peak of breeding birds richness occurred at 2,500~3,100 m a.s.l., supporting the mid-domain effect hypothesis. Meanwhile, as elevation increased, the richness of Oriental species decreased while that of Palearctic species increased. The percentages of Oriental and Palearctic species were similar at 3,100~4,000 m a.s.l.. Accordingly, we estimated that the boundary of Oriental realm and Palearctic realm was at 3,100~4,000 m a.s.l., and the species invasion from Palearctic to Oriental realm was more obvious. Perhaps most significantly, the specific distribution species along the vertical gradients also indicated their corresponding adaptation strategies.