土地利用变化对张掖市生态系统服务价值的影响

Effects of land use changes on values of ecosystem service in Zhangye City

利用1987年、2000年和2009年三期土地利用数据,评估了土地利用变化对甘肃省张掖市生态系统服务价值的影响.结果表明:在整个研究期内,土地利用结构整体变化显著,在1987～2000年间,林地、草地、湿地和水域面积减少,年变化率分别为-4.16%、-3.73%、-4.29%和-2.24%;耕地和荒漠面积增加,年变化率分别为0.82%和0.79%;在2000～2009年间,林地、草地、湿地面积呈增加趋势,年变化率分别为5.79%、5.84%和3.66%;耕地、荒漠和水域的面积在减少,年变化率分别为-0.28%、-0.39%和-3.92%.生态系统服务的静态总价值在整个研究期呈现先减少后增加的趋势,在1987～2000年间,减少了116 570.8万元,在2000～2009年间,增加了39 393.5万元;林地、草地和湿地生态系统价值的增减是导致相应总价值增减的主要原因.基于发展阶段系数和资源紧缺度的生态价值动态估算方法,估算张掖市1987年、2000年和2009年的生态系统服务的动态总价值分别为136 734.8万元、190 341.7万元和171 348.9万元,动态生态价值的研究对指导干旱地区生态保护和水资源合理配置具有重要的实际应用价值.

Land use data of Zhangye City in 1987,2000 and 2009 was used to evaluate the effects of land use changes on the ecosystem service value of Zhangye City.The results indicate that,during 1987 to 2000,land utilization structure changes were remarkable.Areas of rangeland,woodland,wetlands and water body decreased obviously,the year rates of change were-4.16%,-3.73%,-4.29% and-2.24%,respectively,while that of farmland and desert increased clearly,the year rates of change were 0.82% and 0.79%,respectively.From 2000 to 2009,Arears of rangeland,woodland,wetland increased tendency,the year rates of change were 5.79%,5.84% and 3.66%,respectively,while that of farmland,desert and water body showed declining trend,the year rates of change were-0.28%,-0.39% and-3.92%,respectively.The values of Zhangye City＇s ecosystem service lost 1 165.708 million from 1987 to 2000,but raised 393.935 million from 2000 to 2009.The ecosystem service value changes of rangeland,woodland and wetland were the main factors caused the value changes of Zhangye City.Based on the developmental coefficient and scarcity of ecological resources,a dynamic evaluation method was proposed and used to estimate the ecosystem services values of Zhangye City in 1987,2000 and 2009,the results were 1 367.348 million,1 903.417 million and 1 713.489 million,respectively.The study showed that the dynamic evaluation method was useful for the optimal allocation of the natural resources.