国家屏障区生态系统服务权衡与协同

Trade-offs and synergy between ecosystem services in National Barrier Zone

对不同服务间存在的此消彼长的权衡关系和相互增益的协同关系的正确认知,是开展多种生态系统服务可持续管理决策的前提。2018年国家重点专项"典型脆弱生态修复与保护研究"中明确指出要优化"两屏三带"生态系统服务格局,而服务的优化离不开对权衡与协同关系的准确认知。因此,在国家尺度上开展国家屏障区生态系统服务权衡与协同研究具有重要性和迫切性。本文采用RUSLE模型、CASA模型和InVEST产水模型分别评估国家屏障区2000-2015年土壤保持、固碳和产水服务的空间分布格局,并分析三种服务的变化趋势,采用相关分析法和均方根偏差法量化不同服务在各子屏障带整体和空间上的权衡与协同关系。结论如下:①国家屏障区的三项服务在空间上均呈现由东南向西北减少的格局,而在时间上,土壤保持与产水显著增加(p<0.05),增加量分别为20.64 t/(km^2·a)和4.13mm/a,而固碳呈现微弱的上升趋势(p=0.96),服务的提升有利于保障国家生态安全。②在各子屏障带整体上,土壤保持、固碳及产水间相关系数基本大于0(p<0.05),表明三者以协同为主;而在空间上,两两服务间的权衡与协同关系存在着极强的空间异质性,如东北森林带固碳与产水、固碳与土壤保持的权衡关系像元比例分别达49%和27%,且均集中在北部。因此,在进行生态环境建设时,需要同时考虑到整体与局部空间的服务权衡与协同关系的不同,以制定更为合理的生态保护政策。

The better understanding of the trade-off and synergy relationship between different services is the foundation for the sustainable management of decision-making of various ecosystem services. In 2018, the national key special project titled as "Typical fragile ecological restoration and protection research"clearly pointed out that it was necessary to optimize the ecosystem services pattern of"Two ecological barriers and three shelters", and the optimization of services is inseparable from the accurate understanding of trade-offs and synergies. Therefore, it is important and urgent to carry out trade-offs and synergies research in National Barrier Zone ecosystem services on a national scale. In this paper, the RUSLE model,CASA model and InVEST water yield model were used to evaluate the spatial distribution pattern of soil conservation, carbon sequestration and water yield services in the National Barrier Zone during 2000-2015, and to analyze the trends of the three ecosystem services.Correlation analysis and root mean square deviation were used to quantify the trade-offs and synergies between different services in the overall aspect and spatial aspect of each sub-barrier zone. The conclusions are as follows:(1) The spatial pattern of three ecosystem services of National Barrier Zone decreased from southeast to northwest and temporally, soil retention and water yield increased significantly with slope of 20.64 t/(km^2· a) and 4.13 mm/a, respectively.Carbon sequestration showed a slight upward trend(p=0.96). The promotion of services is significantly helpful to the protection of national ecological security.(2) The correlation coefficient among soil retention, carbon sequestration and water production was greater than 0,indicating that the three ecosystem services were synergistic in all sub-barrier zones. Spatially,there is a strong heterogeneity between the trade-offs and synergies, and it is found that the pixel ratio of trade-off between carbon sequestration and water production is 49%, while that between carbon sequestration and soil retention is 27% in the forest barrier of Northeast China.Therefore, it is highly recommended to consider the differences of services in the trade-off relationship among all the sub-barrier zones and spatial areas to make the policy for the construction of sustainable ecological environment.