牛背梁自然保护区食肉目和偶蹄目动物的区系特征与生态分布

Fauna characteristics and ecological distribution of Carnivora and Artiodactyla in Niubeiliang Nature Reserve

牛背梁自然保护区(108°45′～109°04′E,33°47′～33°56′N)位于秦岭山脉东段,地跨秦岭南北坡.采用样线调查法和访问调查法,于2003年5月～2004年8月,对该保护区食肉动物及偶蹄动物的区系特征和生态分布进行了研究.该保护区共有18种食肉动物及偶蹄动物,其中属我国Ⅰ级、Ⅱ级重点保护动物的兽类分别有2种和7种.分析表明,保护区的有蹄类动物物种丰富,秦岭分布的有蹄类在该区域均有分布,但食肉动物种数仅占整个秦岭地区的45.5%.这些兽类中,属于东洋界的兽类有12种,占66.7%;属古北界的仅1种,占5.5%;其余5种为广布种,占27.8%.牛背梁保护区在动物地理区划上应属古北界和东洋界物种交汇的区域,且为东洋界逐渐向古北界过渡的区域.分析该区域食肉动物及偶蹄动物的生态分布发现,这些物种的垂直分布幅度有很大的差异.垂直分布幅度在海拔高差1300 m以上、1000 m左右、450～700 m之间的物种各占1/3.结果还表明,区内这些兽类物种的丰富度随海拔的升高具有先升后降的垂直变化规律.不论是秦岭南坡还是北坡,分布在海拔1800～2200 m区域的兽类物种最多,所占比例大于80%;而在海拔2600m以上区域,兽类种数降至最少,仅占50%左右.兽类丰富度的海拔梯度也体现于这些兽类在各植被类型中的分布上.中山针阔叶混交林中分布的兽类种数最多,而在中低山落叶阔叶林、亚高山针叶林及亚高山灌丛草甸中分布的兽类则较少.

Niubeiliang Nature Reserve （NNR; 108°45′-109°04′E, 33°47′-33°56′N） is located on the eastern range of the Qinling Mountains in Shaanxi province of China and spans the southern and northern slopes of the Qinling Mt. A transect survey and investigation were carried out in NNR to determine the fauna characteristics and ecological distribution of carnivora and artiodactyla from May 2003 to August 2004. The NNR has 18 mammals （carnivore and artiodactyl）, two of which belong to the first class and seven belong to the second class of state key protected wildlife in China. The results of this study indicate that ungulates are abundant in the NNR, as all ungulates that are distributed within the Qinling Mt. can be found within the reserve. However, only 45.5% of the carnivores distributed within the Qinling Mt. were detected within NNR. Among the mammals, there are 12 oriental species （66.7%）, 1 palearctic species （5.5%） and 5 widely-distributed species （27.8%）. The NNR is a crossing area of palearctic species and oriental species on the zoogeographical regions, and it is a transitional area from the oriental realm to the palearctic realm. The results of analyzing the ecological distribution of carnivore and artiodactyl in the area show that their elevational ranges have large differences. The species whose elevational ranges are above 1300 m, about 1000 m, and 450-700 m occupy one third respectively. The results also indicate that species richness for the mammals in the NNR peaks at a middle elevation （rising at first, next descending with elevation ascent）. Not only on the southern slope, but also on the northern slope of the Qinling Mt. , the number of the species distributed in the area at 1800-2200 m is the largest （more that 80%）, while the number of the species distributed in the area above 2600 m is the smallest （about 50%）. Elevation gradients of species richness for the mammals in the NNR also embody the mammal distributions among the vegetation types. The number of the species distributed in the mixed coniferous and broadleaf deciduous forest at middle elevations is the largest, while the number of the species distributed in the broadleaf deciduous forest at middle and low elevations, subalpine coniferous forest, subalpine shrubbery and meadow is relatively smaller.