基于InVEST模型的宁夏盐池县禁牧草地生态补偿标准空间识别

Spatial Recognition of Ecological Compensation Standard for Grazing Grassland in Yanchi County Based on InVEST Model

以农牧交错带宁夏盐池县草地为研究对象,综合集成草地植被与土壤调查、草地信息提取、遥感反演、空间分析等技术方法,基于本地化的InVEST模型,选取碳储存、土壤保持和水源涵养3项关键生态系统服务类型,对禁牧前后(2000年,2015年)草地生态系统服务物质量进行精准评估,在此基础上,采用市场价值法对其价值化,测算禁牧前后草地生态系统服务价值变化量,以此确定生态补偿标准,并借助冷热点、三维趋势分析对生态补偿标准进行不同尺度的空间识别。结果显示:①禁牧以来,盐池县草地生态系统服务显著增强,其中碳储量增加45.66×10^4 t、强度增加0.42 t/hm^2,水源涵养量增加9351×10^4 t、强度增加211.14 t/hm^2,土壤保持量增加2091×10^4 t,强度增加44.93 t/hm^2;②草地生态补偿标准县域为309.21元/hm^2、乡镇尺度介于7.25~1146.36元/hm^2、村级介于3.04~2074.56元/hm^2,村级尺度更能体现草地的生态贡献;③补偿标准的三维趋势呈现由西向东提高、南北向呈"U"型分异的特征,补偿热点区集中于盐池县东南部和东北部。

Ecological compensation standard accounting is the core issue of regional ecological compensation practice,and the accurate measurement of ecosystem service value is the key to scientifically determine the ecological compensation standard.Taking the grassland of Ningxia Yanchi County as the research area,and integrating grassland vegetation and soil survey,grassland information extraction,remote sensing inversion,spatial analysis and other technical methods,three key ecosystem service types,including carbon storage,soil conservation and water conservation were selected and accurately evaluated based on the InVEST model before and after grazing ban(2000,2015).On this basis,grassland ecosystem services value were estimated by using market value method,and the variation of grassland ecosystem services value before and after grazing ban were measured,that of the ecological compensation standard.Furthermore,using the methods of the hotspots and three-dimensional trend analyses to identify the ecological compensation standards at different scales.The results showed that:1)Since the grazing prohibition,the grassland ecosystem service in Yanchi County has been significantly enhanced,including carbon storage increased by 456600 tons,and its intensity increased by0.42 t/hm^2,water conservation increased by 93.51×10^6 t,and intensity increased by 211.14 t/hm^2,soil conservation increased by 20.91×10^6 t,and the intensity increased by 44.93 t/hm^2;2)Grassland ecological compensation standard was 309.21 yuan/hm^2 in Yanchi County,compensation standard on the township scale was between 7.25 and 1146.36 yuan/hm^2,while that on the village level was between 3.04 and 2074.56 yuan/hm^2,and the village-level compensation standard can better reflect the ecological contribution of grassland;3)From the perspective of space,the three-dimensional trend of compensation standard on the village level was gradually improved from west to east and appeared with a U-shaped differentiation from north to south.And the hotspots of compensation standard on the village level were concentrated in the southeast and northeast of Yanchi County.The research can provide method support for regional ecological compensation standard accounting,and provide reference for grassland resource management and ecological compensation practice.