西南生态脆弱区生态承载力时空动态分析

Spatial-Temporal Dynamic Analysis of Ecological Capacity in Southwest Ecological Fragile Region

摘要: 随着经济发展和人类活动的干扰，西南生态脆弱区的生态脆弱性特征进一步凸显。本文采用生态足迹模型，以云南、贵州、四川、广西、重庆五省(自治区、直辖市)为案例区，定量计算了1990年~2008年的生态足迹，从而揭示西南生态脆弱区生态承载力的时空格局。结果表明：1) 从区域整体来看，1990年~2008年，人均生态足迹呈递增趋势，由0.7508 hm2增加到2.1803 hm2，增长了2.90倍；人均生态承载能力总体呈减少趋势，由0.5728 hm2下降到0.4696 hm2，下降了18.01%；生态消耗水平的增加与承载能力的下降，导致西南生态脆弱区人均生态赤字逐年增加，对外来资源的依赖程度增强。2) 从生态足迹和生态承载力生物生产性土地构成来看，耕地的生态空间供给最大，林地和建设用地生态空间供给位列其次；近20年来研究区草地和水域生态供给空间呈减少趋势，化石燃料土地的人均生态足迹增幅最大。3) 从空间格局来看，1990年~2008年西南五省(自治区、直辖市)人均生态足迹均呈增加趋势，其中广西增幅最大，四川最小；人均生态承载力均呈减少趋势，除四川呈先减后增再减的特征外，其他地区都呈先增后减的态势，云南为西南生态脆弱区人均生态承载力减少的主因；1990年~2008年西南五省(自治区、直辖市)生态赤字均呈增加趋势，其中云南生态赤字水平增幅最快。

Abstract: With the economic development and human disturbance, the fragility in southeast ecological fragile area is more remarkable. This paper took Yunnan, Guizhou, Sichuan, Guangxi, Chongqing as a case, used ecological footprint model to analyze the spatial-temporal pattern of ecological capacity in southwest ecological fragile region from 1990 to 2008. The results showed that: 1) For the region as a whole, from 1990 to 2008, the ecological footprint per capita of southwest ecological fragile region showed an increasing trend, from 0.7508 hm2 to 2.1803 hm2, about 2.90 times; The ecological capacity per capita showed a decreasing trend, from 0.5728 hm2 to 0.4696 hm2, about 18.01% decreasing rate; The ecological deficit per capita increased year by year owing to the increase of ecological consumption and the de-crease of ecological capacity. Southwest ecological fragile region depended on external resources increasingly. 2) From the composition of biologically productive land of ecological footprint and ecological, cultivated land supplied the big-gest capacity, followed by forest and construction land. The capacity supply of grass land and water area decreased nearly 20 years. And the ecological footprint per capita of fuel land increased the biggest increment. 3) In the perspec-tive of geographical pattern of change from 1990 to 2008, the ecological footprint per capita of five regions in south-west showed increasing trend. Guangxi displayed the largest increment, while Sichuan the smallest. The ecological ca-pacity per capita of five regions performed decreasing trend, that is, except Sichuan showed the character of de-crease-increase-decrease, other regions showed the character of increase-decrease. Yunnan contributed the most de-crease of ecological capacity per capita of southwest ecological fragile region mainly. From 1990 to 2008, the five re-gions’ ecological deficit per capita showed increasing trend, while Yunnan increased fastest of all.