Impacts Of Climate Change And Human Activities On The Trade-off And Synergy For Ecosystem Service In China From 1992 To 2015

Ecosystem services(ESs)as an important rely on the sustainable development of human society,which provide a rich variety of products and service type,with the development of social economy and the change of natural environment,ESs of the complex interaction between relationship(trade-off and synergy)has become the research focus in the field of geography and ecology.Although there have been extensive studies on the trade-off and synergy of ecosystem services,whose synergy control areas and driving mechanisms were still not fully understood.In addition,it is not clear what role climate change(CC)and human activities(HA)play in carbon sequestration,one of the major ecosystem services,and how it will further affect the trade-offs and synergistic.Based on the data of vegetation,meteorological and hydrological data,land use data,we applied RUSLE model,In VEST model,CASA model and food supply model,adopted unary linear regression,sensitivity analysis,partial derivative,spatial overlay analysis and mutation test,etc.We evaluated the spatial distribution and the trade-off and synergies of four major ESs in China from 1992 to 2015,they are soil conservation(SC),water yield(WY),carbon sequestration(NPP)and food supply(FS).This paper reveals that multi-ecosystem services shows synergistic relationships rather than being limited to the relationship between two ESs in China,identifies synergistic areas among multi-ecosystem service regions,and discusses how CC and HA promote multi-ESs showed synergistic.The results are as follows:(1)From 1992 to 2015,the four major ecosystem services in China increased to varying degrees,with WY,SC and NPP increasing by33.46%,24.13% and 18.63%,respectively.The synergistic relationship between SC and WY was the most concentrated and extensive(73.21% of the areas).In different land types,ES showed an increasing trend in both forest and grassland,and the synergistic effect was mainly concentrated in cultivated land and grassland.Woodlands were the largest provider of all ESs,which providing 54% of SC,40% of NPP and 37% of WY,respectively.(2)In terms of influencing factors,the overall climate increases significantly in temperature and radiation,and the trend of warming and humidity is significant.Between 1992 and 2015,the annual mean temperature(T)increased by 9.5% from 7.8°C to 8.54°C,the average annual Precipitation(P)in China was 805 mm,with the maximum spatial difference reaching 2500 mm.In the past 23 years,the annual variation of Solar radiation(SR)with an increase of 1.76%.The Standardized Precipitation Evapotranspiration Index(SPEI)is-0.38.(3)49.28% of China's land was synergy control areas,while accounted for 82.23% in the SW karst areas.The cause of this phenomenon was precipitation,temperature and the outcome of combined action of ecological restoration engineering.The coverage of NDVI increased significantly after mutation,mainly due to HA.Most importantly,the coincidence rates between the HA dominated areas and the synergies control areas up to 90.7%.So ecological restoration project is the main reason for synergy control in this area.The important things is determine the priorities of a variety of ecosystems synergy,priority areas of ecological restoration for the future to identify diagnosis.(4)38.8% and 61.19% of the carbon sequestration services growth trend in China was contributed by CC and HA,respectively.Among the climate factors,temperature made the largest contribution to the NPP(45.89%)and had the largest control area(36.36%).The contribution of HA to carbon sequestration services(22.8%)was higher than other types of in the areas that changed from farmland to forest land.(5)HA and CC controlled the increase of carbon sequestration in32.84% and 30.15%,and controlled the degradation of NPP in 15.28%and 21.73%,respectively.In 54% of China's regions,CC has enhanced the positive contribution of HA to carbon sequestration,accounting for more than half of 68.35%(36.72% of China's total area).In conclusion,the ecological environment tended to improve during the 23 years,and both vegetation trends and ecosystem services were on the rise.Compared with the previous research,our research to determine the priority areas of a variety of ecosystems synergy,we think the areas of multi-ESs synergy should become the focus of the ecological restoration.In addition,These results emphasized that the synergy control areas should be priority for ecological restoration,which has certain scientific guiding significance for promoting the healthy synergistic development of ecological environment.