汉江流域生态系统服务权衡与协同关系演变

汉江流域是我国南水北调工程的水源地,也是国家重要的生态功能区,定量分析其生态系统服务关系对协调区域发展与保护环境有重要意义。综合利用RS与GIS技术对该区域2000～2015年的土壤保持、碳储量与食物供给服务进行空间制图,并基于空间采样法对3种生态系统服务间的权衡与协同关系进行研究。结果表明:(1)在2000～2015年,汉江流域土壤保持量在波动中下降,高值区位于汉江上游林地、草地交叉分布区域,低值区位于汉江中下游林地、耕地等单一聚集地类区;碳储量年际变化较小,其高低值分布与土壤保持量基本相同;食物供给量增长迅速,高值区位于中下游的平原区,低值区位于上游的山地和盆地区。(2)在权衡与协同分析中,碳储量与食物供给、土壤保持与食物供给之间以权衡关系为主,而碳储量与土壤保持以协同关系为主,各生态系统间权衡与协同关系存在空间异质性。(3)空间热点制图显示,2000～2015年0类服务热点区占比减少,主要地类为草地;1类服务热点区占比最大且呈增加趋势,主要地类为耕地,生态服务类型以食物供给为主;2类服务热点区有所减少,多分布在上游林地区域,服务类型为碳储存和土壤保持;3类服务热点区占比很少。该研究结果对揭示生态系统服务之间的区域差异有重要作用。

Evolution Analysis on Trade-offs and Synergies of Ecosystem Services in Hanjiang River Basin

The Hanjiang River Basin is not only the water source of China's South-to-North Water Transfer Project, but also an important ecological function area of the country. The interaction of ecosystem service in Hanjiang River Basin plays an important role in coordinating regional development and environmental protection. In this paper, we mapped the ecosystem service of soil conservation, carbon storage and food supply in Hanjiang River Basin from 2000 to 2015 by RS and GIS technique, and then studied the trade-off and synergy between the three ecosystem services based on the spatial sampling method. The results are shown as follows: ① In 2000-2015, the soil conservation in Hanjiang River Basin decreased in fluctuations. The high value regions of soil conservation are located in the upper reaches in Hanjiang River Basin, where is forest and grassland cross-area. The low value is in the single-type areas such as forest land or cultivated land in the middle-lower reaches of Hanjiang River Basin. In addition, the annual variation of carbon storage is small, the distribution characteristics of carbon storage are consistent with that of soil conservation. Food supply is growing rapidly, with high region located in plains of the middle-lower reaches, and low value regions in the mountainous and basin areas of upper reaches. ② When analyzing trade-offs and synergies, there are trade-off relationships between the ecosystem services of carbon storage and food supply, soil conservation and food supply. In contrast, the interaction between carbon storage and soil conservation is prone to synergistic. It indicates that trade-off and synergy between multiple ecosystem services have spatial heterogeneity. ③ The results of spatial hotspot mapping show that, from 2000 to 2015, the proportion of category 0 hotspot present a decreasing tendency, and grassland is the main land type of 0 class; The category 1 hotspot distribates in the cultivated land, account for the largest proportion and present an increasing trend, which dominant ecosystem service is food supply. The category 2 hotspot decreases for some extend, mainly distribute in forest areas of the upper-middle reaches in Hanjiang River Basin. The ecosystem services of the category 2 are carbon storage and soil conservation. Moreover, the proportion of category 3 hotspot is very small. These findings contribute to revealing regional difference of ecosystem service.