The Alteration of the Vertebrate Resources Over the Past Two Decades In gansu Anxi Extreme Arid National Nature Reserve

27 Mar The Alteration of the Vertebrate Resources Over the Past Two Decades In gansu Anxi Extreme Arid National Nature Reserve

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Abstract

甘肃安西极旱荒漠国家级自然保护区目前已进行了三次综合科学考察(以下简称科考): 第一次1988–1989年、 第二次2002–2003年、第三次2012–2013年。在三次科考20多年的时间跨度中, 脊椎动物各类群物种多样性发生了一 定的变化: 鱼类增加了2种, 减少了3种土著种; 两栖爬行类种类一直保持稳定; 保护区三次科考记录的151种鸟类 中, 有55.63%(84种)一直稳定分布。因气候变暖, 鸟类区系中东洋界比例增加, 有明显的分布区向西扩散的物种成 分, 同时也有从新疆向东扩散的种类以及高原扩散来的成分。 20年间分布减少的29种鸟类中, 主要为夏候鸟 (41.37%)和旅鸟(48.28%), 这些鸟类的分布消失随机性很大。哺乳类的分布相对比较稳定, 第三次科考没有调查到的 6种哺乳类应该是由于调查方法造成的。新增的小五趾跳鼠(Allactaga elater)是甘肃省啮齿类的一个新记录, 表明该 物种分布区有向东南扩散的趋势。

English Abstract

In Gansu Anxi Extreme Arid National Nature Reserve, three comprehensive scientific investigation,
using line transect and quadrat sampling methods, were conducted every ten-year since 1988 to monitor the
dynamics of natural resources. According to survey data, the species diversities of vertebrates in this region have
changed over the past two decades. Two introduced species of Cypriniformes were found in the reserve, while
three native loach and carp species showed decreased distribution. The distribution and diversity of amphibians
and reptiles were stable over the survey period. Among the 151 avian species recorded during the three surveys,
84 species (55.63%) remain stable in the region. The avifauna belonging to the Oriental Region increased significantly and some species increased their distribution west as a result of climate warming. The changes in bird
species composition over the 20-year period also included new colonization by species from the west and the
Tibetan plateau, and the decreased 29 species mainly including summer migratory species (41.37%) and transient migrants (48.28%). The composition of mammals was relatively stable. The emergence of a small five-toed
jerboa (Allactaga elater), which is also a new rodent record of Gansu Province, indicates a southeastward tendency of its distribution.