土地利用变化下的生态系统服务敏感性研究——以克里雅绿洲为例

Ecosystem Services Sensitivity to Land-use Change:A Case Study of the Keriya Oasis

通过剖析传统的敏感性分析法,提出交叉敏感性概念,评价生态服务价值对土地利用类型转换的响应性。以克里雅绿洲为研究区域,以1991、2002和2011年三期遥感影像数据为基本信息源,运用交叉敏感性分析,计算生态系统服务价值对土地利用类型转换的敏感性,确定生态系统日趋敏感的土地利用变化过程,为土地管理对策提供参考依据。研究结果表明:20 a来,克里雅绿洲生态服务价值较敏感的土地利用转换类型相对稳定,主要集中在湿地和水体向荒漠和低覆盖度草地的转换;与1991和2011年相比,2002年的交叉敏感性系数普遍上升,这主要是因为湿地、水体面积的减少加剧了研究区的生态脆弱性,从而表现出更大的敏感性;湿地和水体向耕地转换的交叉敏感性一直处于上升趋势,并不断接近于-1,表明生态服务价值对高强度的人为活动变得越来越敏感,从而警示地方管理部门采取必要措施制止此种转换的持续。

Land-use change is a major driver behind the loss of ecosystem services.In recent years,a great emphasis has been placed on the responsiveness of ecosystem services value to the land-use change,and the coefficient of sensitivity,as an important indicator,has been widely used for the assessment of this responsiveness.However,the limitation of sensitivity analysis,proposed by Kreuter et al,on this application has been neglected.In this paper,firstly,the reexamination was carried out for the conventional sensitivity analysis,and the concept of cross-sensitivity and its calculation was proposed on this basis,through which it was more intuitive to characterize the responsiveness of ecosystem services value to the mutual transformation between land use types.Secondly,a dynamic analysis was conducted using coefficient of cross-sensitivity for the responsiveness of ecosystem services value to the transformation among land use types in the Keriya Oasis in 1991,2002 and 2011 respectively,noting the processes of land-use change,to which ecosystem services were increasingly sensitive,to provide a reference for land-use policy.The main conclusions were drawn as follows:1) The categories of land-use transformations to which the ecosystem services showed sensitive were stable during the three time points 1991,2002 and 2011,mainly concentrated on the conversions from the land-use types with high ecosystem functionality,i.e.wetland and water body,to the others which are large in size and poor in ecosystem service provision,i.e.desert and low-densitygrass.For example,1% conversion from wetland to desert caused 4.15% loss in ecosystem service in 1991,and 4.45% loss in 2002;1% transformation from water body to low-density-grass led to 1.16% and 1.30% loss in ecosystem service in 1991 and 2002.2) As compared with 1991 and 2011,the cross-sensitivity coefficients generally increased in 2002,mainly due to the decrease in the size of wetlands and water area which exacerbated the ecological vulnerability of the study area,and as a result the value of ecosystem services showed greater sensitivity to such transformations.3) The coefficient of cross-sensitivity for the transformation from wetlands and water body to arable land had been in a rising trend,and continued close to-1,indicating that the value of ecosystem services became more and more sensitive to the intensifying human activities.