| In this paper,based on the understanding of landscape structure characteristics at the lower Jingjiang reach of middle Yangze river,comprehensively evaluated the13 ecosystem services at the lower Jingjiang reach of middle Yangze river from the aspects of value composition,the interaction relation of ecosystem services and the spatial relationship.Based on Landsat7 ETM remote sensing images of the floodplain landscape in the dry season of 2002,classified the floodplain landscape of the lower Jingjiang reach of middle Yangze river,selected 11 and 7 landscape pattern indicators from landscape level and patch type level respectively,to analyze the spatial pattern characteristics of the floodplain landscape of the lower Jingjiang reach of middle Yangze river.At the same time,to build evaluation system of the floodplain landscape at the lower Jingjiang reach of middle Yangze river,and the market value method was adopted to value assessment crops,aquatic products,forest products,et al three services,in combination with flood model and the replacement value engineering method to alleviate flood service evaluation,combined with flood submergence model and substitution cost method,the value of water purification and flood sediment retention was evaluated,by the method of equivalent factor,water supply,water conservation,gas regulation,climate regulation,sediment erosion control,biodiversity,aesthetic landscape value assessment,et al seven services such as pearson correlation coefficient method was used to analyze the interaction relationship between ecosystem services and spatial visualization for the ecosystem services,Moran's I spatial autocorrelation and Getis-ord Gi*were used to analyze the spatial correlation and aggregation degree of ecosystem services,and the following conclusions were obtained.(1)Structural characteristics of floodplain landscape of the lower Jingjiang reach of middle Yangze river.The area size of landscape elements in the Floodplain of the lower Jingjiang reach of middle Yangze river in 2002 as follows:cultivated land>the grass>main channel>floodplain water body>pond>bare land>woodland>construction land,arable land is the dominant landscape element type in the study area,accounting for 46.79%of the total area.At the landscape level,the fragmentation degree and shape regularity degree of the floodplain landscape of the lower Jingjiang reach of middle Yangze river are higher,the patch aggregation is stronger,the maximum patch dominance is higher,and the complexity of landscape structure is lower.At the patch level,the fragmentation degree and shape complexity of floodplain water body and construction land are the highest,while the fragmentation degree and shape complexity of forest land and main river are the lowest.The patch aggregation degree and patch dominance degree of cultivated land and main river channel are the largest,while the patch aggregation degree and patch dominance degree of floodplain water body and construction land are the smallest.(2)The value composition characteristics of landscape ecosystem services in the floodplain of the lower Jingjiang reach of middle Yangze river.The total value of landscape ecosystem services in the floodplain of the lower Jingjiang reach of middle Yangze river is 44.958 billion yuan,and the service value per unit area is 32.5275million yuan/km~2,which is composed of supply service,regulation service,habitat and biodiversity service and cultural service,accounting for 7.99%,89.63%,1.48%and 0.90%of the total value successively.The value of supply service is 3590.6104million yuan,and the value of component service as follows:aquatic products>crops>water resources supply>forest products;The value of regulation service is40296.0743 million yuan,and its component service value as follows:hydrological regulation>climate regulation>sediment regulation>gas regulation>water purification,in which hydrological regulation service is composed of flood mitigation and water conservation,the value of which is 28412.1715 million yuan and 9854.1248million yuan respectively,sediment regulation service is composed of flood sediment retention and sediment erosion control two service indicators.It values 167.0530million yuan and 4770.4136 million yuan respectively;The value of habitat and biodiversity is 666.5648 million yuan,only including biodiversity services;The value of cultural services is 405.246 million yuan,only including aesthetic landscape services.(3)The interaction between ecosystem services.The synergistic relationship among the ecosystem services in the floodplain landscape of the lower Jingjiang reach of middle Yangze river is significant,and there are multiple highly synergistic ecosystem service clusters,among which the service cluster composed of flood mitigation,water purification and flood sediment retention has the strongest synergistic relationship.The trade off relationship between agricultural products and other 12 services mainly existed,among which agricultural products and climate regulation,sediment erosion control,biodiversity,aesthetic landscape,et al services had the strongest trade off effect.(4)Spatial relationship of landscape ecosystem services in the Floodplain of the lower Jingjiang reach of middle Yangze river.The spatial distribution patterns of agricultural products,aquatic products,forest products,water supply,water conservation,climate regulation,sediment erosion control,aesthetic landscape,gas regulation and biodiversity were related to the distribution patterns of landscape elements.The spatial distribution pattern of flood mitigation,water purification,flood sediment retention and other services is consistent with the flooded area,and the high values are concentrated in the area with low elevation and connectivity to the main river channel.The total value of landscape ecosystem services in the floodplain of the lower Jingjiang reach of middle Yangze river is mainly medium and low,and the low value is mainly distributed in the landscape elements with more concentrated human production activities,while the high value is concentrated in the aquatic ecosystem of the study area.(5)The spatial clustering phenomenon of floodplain landscape of the lower Jingjiang reach of middle Yangze river ecosystem service is obvious,with low low clustering value is given priority to,including low clustering are mainly distributed in the human production activities more gathered landscape types,its cold spot region focused on the upstream and middle and lower reaches of the study area is relatively concentrated areas,human activities such as the hot spot is concentrated in a hierarchical and downstream of the water ecological system.The overland ecosystem services of the lower Jingjiang reach of middle Yangze river are greatly affected by landscape factors such as patch area size,fragmentation degree and maximum patch dominance degree. |
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