农用地时空变化对大熊猫生境的影响:以岷山中部地区的白草河流域为例

Impacts of spatio-temporal changes in agricultural land on giant panda habitat:A case study in the Baicaohe watershed of the mid-Minshan Mountains

岷山中部地区是我国野生大熊猫(Ailuropoda melanoleuca)种群分布密度较高的地区之一,但近年来砍伐森林、种植药材等农业活动较为突出,可能对大熊猫及其生境利用造成不利影响。为了明确该地区农用地的时空变化特征,及其对保护区内外大熊猫生境的影响,我们采用遥感影像解析、GIS空间分析和野外调查相结合的方法在白草河流域进行了本项研究。结果表明,该流域的农用地主要分布在海拔1,700m以下的地区。从1994-2008年,农用地面积呈现先减少后增加的趋势:1994-2001年间,农用地面积减少,减少区域主要在海拔1,700m以下的地区;2001-2008年间,农用地面积增加明显,增加区域主要在海拔1,700m以上的高海拔地区和自然保护区周边。农用地扩张直接导致1994-2008年间该地区5,281hm2(6.46%)的大熊猫生境丧失。就保护区内外而言,保护区外部大熊猫生境的丧失比例达21.53%,而保护区内部的生境变化不大。为了有效保护该地区的大熊猫生境,除了禁止在自然保护区内部进行开发外,建议对保护区外部的大熊猫生境进行保护,禁止在海拔1,700m以上的高海拔地区进行土地开发。

The mid-Minshan Mountains is one of the regions encompassing the most densely populations of giant pandas in China. Increasing agricultural activities in the area, involving deforestation and herbal medi- cine cultivation may negatively influence the giant panda and its habitat. To understand spatio-temporal changes in agricultural land and its impact on giant panda habitat, we conducted this study, using a combina- tion of remote sensing, GIS spatial analysis and field surveys, in the Baicaohe watershed of the mid-Minshan Mountains, Sichuan. Agricultural land was mainly distributed below 1,700 m elevation, and its total area first decreased and then increased between 1994 and 2008. Area of agricultural land decreased below 1,700 m between 1994 and 2001, but it increased in higher-elevation areas surrounding the nature reserves between 2001 and 2008. Expansion of agricultural land directly caused a loss of 5,281 hm2 （6.46%） of giant panda habitat between 1994 and 2008. As negligible amounts of habitat affected inside the reserves, 21.53% of habitat outside the nature reserves were destroyed. To protect giant panda habitat in this region, not only ag- ricultural cultivation should be prohibited in high-elevation zones adjacent to the nature reserves, but also, habitat outside the nature reserves should be protected as well as inside.