Based On Scenario Simulation, The Study Of Ecosystem Service Trade-off And Synergy Between Guanzhong And Tianshui Economic Zone

Social economy has been rapidly developed for more than 30 years after China's reform and opening up, and ecological problems are more and more serious along with the economics'development. Rapidly growing economic of the Guanzhong-Tianshui economic region takes too many natural resources, which is beyond the self-regulation of ecosystem, thus destroying the balance of ecosystem severely. Ecological protection is starting to get more and more attention as the deterioration of people's living environment. This research discussed the effects of policy and climatic change on land-use and ecosystem services under the background of global warming. The paper analyzed the trade-off and synergic between ecosystem services and found the impacts of policy and climatic change on ecosystem services by comparing possible developing scenarios of the future, which providing a reliable basis for achieving the sustainable development of ecosystem.The research's main contents are:(1) Calculating the ecosystem services of carbon sequestration, soil conservation and water yield in the Guanzhong-Tianshui economic region in 2010, and analyzing the spatial distribution characteristics of three kinds of ecosystem services in 2010. (2) Setting a variety of scenarios which covers policy and climatic change, predicting the distribution of land-use types in 2050, and estimating three kinds of ecosystem services in various scenarios in 2050 according to the distribution of land-use types. (3)Analyzing trade-off or synergy among carbon sequestration, soil conservation and water yield and discussing the impacts of policy and climatic change on three kinds of ecosystem services.The results are as follows through this study:(1) Urban land has the largest increase in the RCP6.0 related scenarios compared to other four representative concentration paths scenarios providing by IPCC, and have an obvious expansion in central and mid-east flat area of Guanzhong-Tianshui economic region which adapts to urban development. Forest lands have the largest increase in the RCP2.6 related scenarios, and have an obvious expansion in south and west area of high-lying ground and rough terrain. A large number of grassland, unused land and a small amount of cultivated land transformed into forest land, which makes forest land becoming the largest land-use type of the area among same policy scenarios. A large area of forest land transformed into cultivated land and grassland in the RCP4.5 related scenarios, which makes cultivated land become the largest area among same policy scenarios. In terms of policy influence, urban area has small expansion after letting go of the one-child policy, and urban has outward development; the implementation of carbon tax policy affects forest land area significantly and makes a large area of forest land scatter the high-lying ground and rough terrain.(2) After simulating three kinds of ecosystem services in 2050 by combining three kinds of ecosystem services in 2010, the results show, the amount of carbon sequestration and soil conservation presents minimum when carrying out none carbon tax policy and no one-child policy in the RCP4.5 climatic scenarios and presents maximum when carrying out the carbon tax policy and the one-child policy in the RCP2.6 scenario. The amount of water yield presents maximum when carrying out none carbon tax policy and the one-child policy in the RCP4.5 climatic scenarios, and presents minimum when carrying out the carbon tax policy and no one-child policy in the RCP2.6 scenario.2When under the same policy scenarios and different RCP scenarios, the scenarios of high total amount of carbon sequestration and soil conservation appeared with low amount of water yield, and the scenarios of low total amount of carbon sequestration and soil conservation appeared with high amount of water yield. When in the same climatic development mode, the scenarios of high total amount of carbon sequestration and soil conservation caused by policy appeared with low amount of water yield as well.(3) Carbon sequestration, water yield and soil conservation have an obvious mutual relationship in the Guanzhong-Tianshui economic region, including obvious trade-off relationship between carbon sequestration and water yield, obvious synergic relationship between carbon sequestration and soil conservation and obvious trade-off relationship of water yield and soil conservation. In the most increased carbon sequestration scenario, soil conservation also has the most increase, and water yield quantity has the most reduction; in the least reduced water yield scenario, the amount of carbon sequestration and soil conservation have the least increase.(4) Climatic change and implementation of policy have obvious impact on the change of ecosystem services in the Guanzhong-Tianshui economic region, which shows ecosystem services in various scenarios have obvious differences in different climate scenarios and the same policy scenario. The implementation of carbon tax policy has a larger impact on the forest land, it limits the transformation from vegetation to cultivated land and urban land and increases the ability of water interception, so the carbon tax policy has negative effects on water yield and positive effects on soil conservation and carbon sequestration. The implementation of one-child policy's effect on urban land are obvious. After letting go of the one-child policy, urban has an external expansion resulting in vegetation of urban edge turned into urban land, thus decreasing the capacity of carbon sequestration and soil conservation.The highlights of this research are that our research is based on the combination of climate scenarios offered by the fifth report of IPCC and policy scenarios including one-child policy and carbon tax policy. We used Land Change Modeler of IDRISI software simulated and analyzed land-use maps of 16 future scenarios in 2050. Carbon sequestration, soil conservation and water yield were quantified based of those land-use maps and different models. We also analyzed trade-off and synergy among each ecosystem service and discussed why those interactions happened. Multi-scenarios has been proved to be a valid method which can be used in the analysis of trade-off and synergy among ecosystem services. This research can be used as a reference for further related researches.