| The ecosystem service, which comprises of support services, regulating services, supplying services and cultural services, is the the foundation of subsistence and development of human beings. To realize the maximization of supplying services, human begin transformed the ecosystem by LUCC with the development of economy, population and living standard. However, many unreasonable exploitation caused the degeneration of ecosystem services, and influenced the welfare of contemporary human and ecological security in some place even around the world. At the same time, that vastly weakened the benefit of production and lifestyle which is bad for sustainable development. As a result, it's important to research the trade-off and synergy among ecosystem services. Because it can manage ecosystem services, and find the balance point between economic development and environmental protection, and the balance point of coordinate development of ecosystem services.The environment in northwest of China is vulnerable. But it has great pressures in economic development and population growth. The conflict between economic development and environmental protection become more and more severe. This research compare the GuanZhong Basin which is the economic center of northwest and the HanZhong Basin which is the ecological preservation area in Shaanxi. It taked the number, degree, regional difference of LUCC to analyze. And it also analyzes the spatial and temporal disparities of ecosystem services according to the ecosystem services data from 1990 to 2010 which include NPP, water conservation function, food supply. At last, it analyzes the spatial and temporal disparities of the trade-off and synergy of ecosystem services by correlational analysis method, linear regression method, and the like. The main conclusion are summarized here:(1)From 1990 to 2010, the change of land use in two basins were great, the intension of land use improved. In both of the GuanZhong Basin and the HanZhong Basin, the cropland area reduced and built-up land expanded. During 21 years in GuanZhong Basin, the area of cropland area reduced by 210776.27hm2 and the built-up land increased by 216702.80hm2. In HanZhong Basin, the area of cropland area reduced by 3664.88hm2 and the built-up land increased by 2861.61hm2. GuanZhong Basin are formed by cropland, grassland and woodland. HanZhong Basin are formed by woodland, grassland and. cropland. According to transfer matrix, cropland was the main source of increasing in built-up land. The fast dynamic growth of two basins land use were from 1995 to 2000. The degree of land use in two basins continually increased in past 21 years. But the land use in GuanZhong Basin were higher than it in HanZhong Basin and it increased quickly from 1995 to 2000. The relative variation ratio of each land category in GuanZhong Basin were higher than its in HanZhong Basin.(2)The value of three ecosystem services have their own features in temporal variation and spatial distribution of two basins. All of the NPP, water conservation function and food providing in two basins increased in the past 21 years. The total value and growth rate of three ecosystem services in GuanZhong Basin were higher than them in HanZhong Basin. In respect of the value per area, HanZhong Basin's NPP and water conservation function were higher than them in GuanZhong Basin. But its food supply were fewer than its in GuanZhong Basin. In addition, the growth rate of value per unit area were lower than it in GuanZhong Basin. In respect of land use, high NPP were provided by woodland and grassland. High water conservation function were provided by woodland and grassland and water. High food supply were provided by cropland. In GuanZhong Basin,cropland, woodland and grassland ranked the top three land type in contributors for the value of NPP and water conservation. The rank in HanZhong Basin is woodland, grassland and cropland. In two basins, the rank of contribution for the total value of food providing is cultivated land, grassland and waters. In view of spatial distribution, the high value areas of NPP and water conservation in GuanZhong Basins is located in the mountains around the basin edge, and the low value area is located in the central plains of basin. In HanZhong Basins, the value of two services is high in north and low in south. The spatial distribution of the food supply is the opposite, and the high value area of food providing is located in the cultivated land of the central of the basin, and the low value area is located in the forest and urban area.(3)The trade-off and synergy among the three services presented dynamic change characteristics in 21 years. My result show that trade-off between NPP and water conservation, and synergy between NPP and food providing, water conservation and food providing. The average value of correlation coefficient between NPP and water conservation is 0.097 in GuanZhong Basin, and 0.388 in HanZhong Basin. The correlation coefficient between NPP and food providing is -0.429 in GuanZhong Basin, and -0.207 in HanZhong Basin. Hence it may be concluded that the tradeoffs among ecosystem services in GuanZhong Basin is stronger than HanZhong Basin, while the synergy is lower than HanZhong Basin. From 1990 to 2010, the synergy relationship showed a weakening trend, while the trade-off showed a enhanced trend. Even more, the rate of change in GuanZhong Basin is faster than HanZhong Basin.(4) The trade-off and synergy of ecosystem services in two basins have outstanding regional differences. In respect of synergy, the growth of NPP with the growth of water conservation in cultivated land in west and east of GuanZhong Basin, and forest and grassland in northeast and southwest of GuanZhong Basin, and mountain region in northwest of HanZhong Basin. The growth of NPP with power function growth of the water conservation in the cultivated land in east of GuanZhong Basin and the west region of Ningqiang county and Lveyang county in HanZhong Bsin. The strongest synergy relation is Weinan city and Mianxian county, and the weakest is Tongchuan city and Xixiang county. In respect of trade-off, the growth of NPP with the decline of food providing in the middle region of GuanZhong Basin and east region of Hanzhong Basin. Even more, The growth of NPP with power function decline of food providing in the Tongchuan city and Qin mountain in Xi'an and the south of Xixiang county. The strongest trade-off relation is Xi'an city and Zhenba county, and the weakest is Baoji city and lveyang county.(5) The temporal and spatial of trade-off and synergy are analyzed for consecutive 21 years, which is one of the main characteristics in the study. The shortcoming of a single or a few time nodes in previous research has been broken, and the dynamic study of ecosystem services has realized. Meanwhile, the fundamental has been provided to realize the space expression of the tradeoffs and synergy. Accordingly, the regional differences have been analyzed in the study area, provided the basic theories for practice the ecosystem management with local conditions. The other characteristic is comparative study of GuanZhong Basin and HanZhong Basin, and analysis the relationship between LUCC and ecosystem services in economic development region and environmental protection area. Thus the case foundation has been provided for policymaking of ecosystem management with local conditons. |
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