A Multi-scale Study On The Response Of Ecosystem Services And Anthropogenic Disturbances In Eastern Sichuan

As one of the most important ecological function areas in the middle and upper reaches of the Yangtze River,The eastern Sichuan,is of great significance to the ecological health and sustainable development for China.In pursuit of high GDP,large areas of farming and deforestation in eastern Sichuan caused frequent floods and serious environmental problems such as soil erosion and vegetation degradation in the Yangtze River,restricting the local social and economic development.The servious ecological environment and unreasonable land utilization have declined the local sustainable development.How to coordinate the relationship between human disturbance and environmental protection has become one of the most urgent problems for sustainability.From the perspective of ecosystem services,this article is at three research scales(at Country Scale,at Grid Scale,and at High-resolution Scale)to use remote sensing image data in 1990,1995,2000,2005,2010,and 2015 in eastern Sichuan and 2019 in Chongqing to analyze fellowing aspects,(1)the environmental health status of eastern Sichuan,(2)the spatial relationship between ecosystem services and human disturbance in eastern Sichuan,and(3)the accessibility to ecosystem services for different residential types in Chongqing.The results show that:1.At country scale,the ecological conditions of eastern Sichuan from 1990 to 2015 showed two stages.The first stage was the period of 1990-2000.The farmland and forestland in eastern Sichuan changed irregularly and drastically,and reduction rate of grassland increased.Ecosystem services value(ESV)correspondingly changed direction lessly,and the ecosystem health state is declining year by year.The second stage is the period of 2000-2015.Affected by the Grain to Green Program,the farmland in eastern Sichuan decreased with the water-land of forestland increasing significantly,and the rate of grassland shrinkage decreased gradually.In turn ESV rose steadily and even reached 255.829 billion yuan in 2015.Forestland contributes the most to ecosystem services,followed by grassland and waters,and farmland is the least.Ecosystem health value has been steadily improved and reached the best state in 2015.However,the building-land has continued to increase from 1990 to 2015,which has a significant negative effect on the local ESV and ecosystem health state.2.At grid scale,based on the spatial difference of ESV in eastern Sichuan,three heterogeneous clusters,namely cold-spot area,hot-spot area,and random area,are constructed,and the impact of human disturbance on ecosystem service value is significantly different across three heterogeneous clusters.The weakest negative effect of human disturbance on the ESV is in the hot-spot,fellowing by the cold-spot,and the strongest is in the random area.Such negative effect gradually increased from 1990 to 2000 but weaken along 2000 to 2015.Additionally,there is a significant spatial dependence between the disturbance factors(population density,GDP,and terrain)and ESV,and there are obvious differences between different heterogeneous regions.The spatial dependence of population density on ESV is negative in all three heterogeneous regions.The mechanism of terrain and GDP is more complex.Terrain and ESV are negative in hotspots but positive in the cold spot area and random area.And the spatial response of GDP on ESV in each cluster is showed as an invepted "U" along the X axis,running through the positive and negative intervals,implying that ESV and economy may achieve a "win-win" within a certain interval.3.At high-resolution scale,different resident types in Chongqing have obvious unfairness in enjoying ecosystem services.The second resident(ordinary communities in the urban area)can enjoy the most least in ESV.The third resident(rural homestead)is the most rich in ESV.However,the first-class resident(villa area)has the best site For the reason that such sites enjoys high ESV and convenient basic living facilities(transportation)for balancing ecology and life.In addition,there is no direct relationship between the number or size of parks and available ESV.Based on the above results,firstly we should adhere to the ecological environmental protection strategies.Secondly,we need adhere to the red line of farmland and pay attention to improve farming technology for change low-yield fields to high-quality fields.Thirdly,we must rationally partition planning.For urban area,we should control the unlimited spread of urban agglomeration.For conservation areas,we should also strengthen protection and avoid the destructive effects of human interference.Finally,avoiding green coverage area as the only planning indicator,we should gradually introduce the concept of ecosystem services to urban green planning,and pay attention to the fairness of ESV.