Guanzhong—Tianshui Economic Zone Ecosystem Carbon Sequestration Service Spatial Flow And Pattern Optimization

Carbon sequestration is an important part of regulating services in ecosystem services,in which the balance between supply and demand is the focus of scientific research by experts and scholars from all over the world.In the context of global climate change,China's carbon emissions trading market will start soon,the development model of low-carbon economy will have an important impact on the regional ecological environment and economic development.As the low-carbon age is upcoming,to estimate the regional carbon budget in advance is helpful to identify the position of carbon market in China.Adjusting regional spatial layout after a measure of carbon budgets is a more comprehensive and scientific approach of rational planning and development of the low carbon target.Therefore,taking the Guanzhong-Tianshui Economic Region as the research area,this paper quantified the balance of supply and demand of carbon sequestration service,simulated the spatial flow of carbon sequestration service,revealed the spatial rules of service functional shift of regional carbon sequestration,and put forward the optimization strategy of regional spatial layout which offered us intuitive scientific reference to guide the low carbon development of regional economic society.The main contents of this research include:(1)to estimate the quantity of carbon sequestration service demand and supply in the study area,from the perspective of systematic carbon balance,to compare and analyze the relationship between the quantity of supply and demand and to quantify the supply and demand balance of regional carbon sequestration service;(2)from the perspective of geographical space,to analyze the spatial pattern of regional carbon sequestration service and to simulate the flow condition of carbon sequestration service in the study area;(3)based on Bayesian theory and entropy reduction,to analyze the influence of environmental variables on the supply of carbon sequestration service,to display the spatial distribution region of the combinations of key variables and to quantize the supply uncertainty of carbon sequestration service of them,and to give the optimization strategy of space layout.The main conclusions are as follows:(1)Ecosystem carbon sequestration services overall supply is greater than demand,but differences between regions.In general,carbon sequestration service demand is less than the supply in the Guanzhong-Tianshui Economic Region,the demand for high value areas are mainly distributed in the high population areas of Guanzhong plain,the supply of high value areas are mainly distributed along the Qinling Mountains and the Beishan mountains.In the study area,the demand for carbon sequestration is obviously different in the space,among which the demand of Xi'an is the highest,followed by Xianyang and Weinan,Baoji and Tianshui are slightly lower,Shangluo and Tongchuan are the second,and the lowest is in Yangling district.The regional carbon sequestration service supply is divided into biology carbon pool and soil carbon pool,and the spatial distribution trend of the two groups is similar.The carbon sequestration capacity of the region is better,and the area of carbon sequestration per unit area of 1.50kgC/m2 is 9.23× 103 km2.Among them,the capacity of biology carbon sequestration in Baoji is the highest,the carbon sequestration in Tongchuan and Yangling is the least,and the carbon sequestration in other cities is relatively balanced.The soil carbon sequestration stocks showed a clear gradient trend,and the soil carbon sequestration capacity in Baoji was much higher than that in other cities;(2)Regional ecosystem carbon sequestration services space flows significantly.According to the distribution of the flow rate(Ri)in the study area,the region could divide into 3 carbon source sub regions:The center of carbon agglomeration centered on Tianshui(Ri>0.04),the center of carbon agglomeration centered on Binxian county(Ri>0.04),and the center of carbon agglomeration centered on Xi'an(Ri>0.20)which extends outward to form a demand cluster of multilevel carbon sequestration.The region of lowest Ri(?Ri?200)is in some counties mainly along the Qinling mountains and Beishan mountains;the region of lowest Riis in Baoji and Tianshui which are on the west side of the study area(400<?Ri?800)and in some counties of Guanzhong Plain Area(? Ri>800);(3)Low-carbon target-oriented optimization of the spatial pattern of priority should be protecting carbon sequestration core area and suitable and reasonable industrial layout planning.Based on Bayesian theory and the actual situation of the study area,the key variables set of optimal biology carbon sequestration capacity is the set { DEM=3,PET=1 },the key variables set of optimal soil carbon sequestration capacity is the set{ NPP=3,DEM=3 }.According to the optimal variable set,the core protected areas and suitable development areas of biology and soil carbon pools are drawn and the suggestions of spatial pattern planning are offered.Innovations of this paper are as follows:(1)Using a form of spatial visualization to describes the ecosystem services flow's process of carbon sequestration from producing areas to use areas,reveals the spatial rules of service functional shift of carbon sequestration in study area;(2)Based on Bayesian principles to explore the uncertainty of spatial pattern optimization which is low-carbon target-oriented.