流域生态系统服务热点与冷点时空格局特征

The spatial-temporal pattern of hotspots and coldspots of ecosystem services at the watershed scale

生态系统服务热冷点的识别及其空间格局特征研究对生态保护规划有着重要的意义。目前有关生态系统服务热冷点的识别多采用直接分类法,缺乏对空间关系特征的综合研究。以延河流域为例,综合集成多源数据来模拟4种生态系统服务(土壤保持、植被碳固定、产水、洪水调节)的热点与冷点时空格局变化特征。主要结论为:(1)2001—2012年,延河流域土壤保持服务在流域下游高于上游,中游地区增长较快。植被碳固定服务和洪水调节服务在流域南部地区较强,且在中下游呈上升趋势。产水服务呈现"南北低、中间高"的分布格局,在流域上游呈下降趋势,在中下游呈上升趋势。(2)生态系统服务热点主要分布在延河中下游南部地区,冷点主要分布在延河上游地区。延河中下游南部地区4种生态系统服务均较强。生态系统服务保护效率最高的是延河上游。(3)延河流域林地的土壤保持服务、植被碳固定服务和洪水调节服务均强于其他土地利用类型,而产水服务较弱,湿地则相反。草地的土壤保持服务和植被碳固定服务相对较强。耕地的4种服务强于裸露地,裸露地的4种服务均较弱。湿地的土壤保持服务、植被碳固定服务和洪水调节服务保护效率最高,林地的产水服务保护效率最高。研究结果以期为流域生态系统服务保护与恢复决策提供理论支撑。

There is a great significance for ecological protection planning to identify the hotspots and coldspots of ecosystem services and to research their spatial-temporal patterns.Nowadays,direct classification is used in identification of the hotspots and coldspots of ecosystem services,but there is no comprehensive research on the characteristics of their spatial relationships.Taking the Yanhe River basin as an example,comprehensive multi-source data integration was used to simulate the changes in the spatial-temporal patterns of hotspots and coldspots of four ecosystem services(soil conservation,vegetation carbon sequestration,water yield,and flood regulation).The main conclusions of this paper are as follows:①During 2001-2012,the soil conservation service in the Yanhe River basin was higher in the lower reaches than in the upper reaches,while its growth in the middle reaches was rapid.The ecosystem services of vegetation carbon sequestration and flood regulation were strong in the southern region of the basin and were rising in the middle and lower reaches.The distribution pattern of water yield fit a model of"high value in north and south,and low value in middle",which shows a downward trend in the upper reaches of the basin and an upward trend in the middle and lower reaches.②The hotspots of ecosystem services are mainly distributed in the south of the middle and lower reaches of Yanhe,while the coldspots are mainly distributed in the upper reaches of Yanhe.The four ecosystem services were all strong in the south of the middle and lower reaches of the Yanhe River.The area with the highest efficiency of ecosystem service protection was the upper reaches of Yanhe.③The ecosystem services of soil conservation,vegetation carbon sequestration,and flood regulation were better in forest lands in the Yanhe River basin than they were in other land-use types,while the water yield service was weaker.The wetlands were the opposite.Soil conservation and vegetation carbon sequestration were relatively better in grasslands than in other land-use types.The four services were stronger in cultivated land than in bare land,and the four services were much weaker in bare land than in other land-use types.The land-use type with the highest conservation efficiencies of soil conservation,vegetation carbon sequestration,and flood regulation was wetlands,and the land-use type with the highest conservation efficiency of water yield was forest lands.The results of this study are expected to provide theoretical support for the conservation and restoration of ecosystem services in watersheds.