生态建设15年黄土高原生态足迹时空变化

作为典型生态脆弱区和重点土壤保持功能区,黄土高原自20世纪80年代以来进行了一系列重大生态工程建设,力图改善脆弱的生态环境。这些重点工程在短期内是否从根本上改善了其生态安全状况是亟待理解的一个科学问题。基于生态足迹思想与方法,定量分析了1995年、2000年和2010年三个阶段15年间黄土高原生态足迹和承载力的时空变化。结果表明：① 1995-2010年15年间黄土高原承载力小于生态足迹,总体上处于生态赤字状态。② 黄土高原人均承载力呈现明显的空间异质性,1995-2010年高值区在中北部,其他区域为低值区,由东向西递减;人均生态足迹自东南向西北递增。③ 生态压力指数从1995年的1.059上升到2000年1.165,增幅较小,2010年上升为2.181,高原整体上处于生态赤字状态。

Spatial-temporal changes of ecological footprint in the Loess Plateau after ecological construction between 1995 and 2010

The Loess Plateau is a key ecological fragile area in China, so Chinese central government has taken a series of measures such as small watershed management, key projects for soil and water conservation, and Grain for Green Program to address the eco-environmental issues of the Loess Plateau since the 1980s. Whether these ecological projects have totally taken effect on the ecological security in the Loess Plateau is an urgent need to understand. Based on the ideology and methodology of ecological footprint, this work quantitatively analyzed the spatial-and temporal changes in the appropriation of the bio-productive areas/carrying capacity and ecological security in the study area over the 15-year period from 1995 to 2010. The results demonstrated the following: (1) the carrying capacity was lower than the ecological footprint (the appropriation of the bio-productive areas), with an ecological deficit for the 15 years; (2) the carrying capacity per capita substantially presented a spatial heterogeneity, with a high value in the northern and central parts and low value in the rest parts of the plateau, and decreased from the east to the west over the period from 1995 to 2010. However, the ecological footprint increased from the southeast to the northwest of the Loess Plateau during the same period; and (3) the indices of ecological stress increased from 1.059 in 1995 to 1.165 in 2000 and 2.181 in 2010, which suggested the growing ecological stress in this region. The spatial pattern of ecological security was consistent with spatial distribution of the ecological footprint. The results of this work demonstrated that, although ecological security has partially improved, the issues for ecological security have been still pressing in the Loess Plateau as a whole.