Study On The Trade-Off And Synergy Relationship Among Ecosystem Services In Poyang Lake Region,China

Poyang Lake region is the core area affected by Poyang Lake,the largest freshwater lake in China,which is an important production base of grain,cotton,oil and fish,is a vital ecological function protection area in China,and is characterized by rapid urbanization,high land utilization,diverse ecological function and fragile ecological environment.It seems of great significance to measure ecosystem services in this region and to explore temporal differences and spatial patterns of trade-off and synergy between ecosystem services for realizing regional sustainable development.Basing on multi-source data of remote sensing,soil,meteorology and DEM,taking ENVI 5.2,ArcGIS10.2,SPSS 22.0 and Origin 9.1 as data processing platforms,and using land use data of different periods obtained by remote sensing interpretation,this article quantitatively measures food supply service,soil conservation service and water yield service in Poyang Lake region from 2005 to 2015,and analyzes spatotemporal patterns and evolution characteristics of the services.Then the spatial and temporal characteristics of trade-off and synergy between services on the scale of 1 km×1 km is analyzed by using correlation analysis,hot spot analysis and spatial mapping method,the distribution regularity of hot spots of ecosystem services is explored,and the difference of trade-off and synergy and hot spots areas among counties and land types is also studied,which can provide data support and methodological reference for relevant research,and provide reference for achieving"win-win"of regional development and ecological protection.The main conclusions of this paper as follows:(1)From 2005 to 2015,cultivated land is the main land use type in Poyang Lake region showing a decreasing trend,forest land and waters are supplement with the former decreased,the latter increased,and construction land seems less but increased obviously.Spatially,cultivated land,forest land and waters are widely distributed,and they show a circular distribution pattern from forest land to cultivated land to waters from outside to inside.While construction land is concentrated in County or district administrative center presenting a significant spatial expansion trend.The transfer area of land use type is4498.95×10~2 hm~2,mainly in cultivated land and forest land.(2)During the study period,food supply service increased,soil conservation service decreased,and water yield service increased first and then decreased in Poyang Lake region.Spatially,the distribution of food supply service presents"low high-low-high"in the northwest to southeast direction with a strip-like spatial variation,soil conservation service is concentrated in high and low value showing increasing in the north and decreasing in the south,and water yield service is high in south and low in north,with the same spatial change characteristics as soil conservation service.Nanchang County is the high value of three services,while Jiujiang City,Duchang County and De’an County is the low one of food supply service,soil conservation service and water yield service respectively.(3)The relationship of food supply and soil conservation or food supply and water yield in the Poyang Lake region is trade-off,and the one of soil conservation and water yield is synergy.Moreover,the relationship among three services presents obviously different spatial pattern,in food supply and soil conservation showing northern synergy and southern trade-off,in food supply and water yield displaying distinctly spatial trade-off,and in soil conservation and water yield existing synergy-tradeoff-synergy differentiation like a"sandwich"from north to south.(4)Among land use types,there is a significant synergy between cultivated land and food supply,garden land and soil conservation,water area and water yield,and construction land and three services are all trade-off.During 2005 to 2015,none land use type shows the supply capacity of three services increased in Poyang Lake region,and all decreased in cultivated land,grassland and unused land.Two services adding and one service reducing are waters and construction land,while One increasing and two services decreasing is forest land.The relationship of food supply and soil conservation or food supply and water yield is mainly trade-off in land use types,and that of soil conservation and water yield is synergy in cultivated land,garden land,grassland and construction land,while trade-off in waters and unused land.(5)Hot spots identification shows single service hot spots area has expanded.Hot spots in food supply presents semi-circular spatial distribution in the east to south direction,that in soil conservation shows circular spatial distribution pattern from outside to inside,and that in water yield is concentrated in the middle with non-hot spots around.Hot spots of multi-ecosystem services are different among counties and land use types,but in general,they are mostly located in the eastern and southern plain areas,which have flat terrain,good soil conditions,so that own capacity to provide multiple ecosystem services.