Tradeoff Analysis Of Ecosystem Services In The Karst Mountainous Area

The diversity of ecosystem services and the variety of land uses by humans lead to reciprocal tradeoff or synergic relationships between different ecosystem services.Analysis the tradeoff and synergy relationship between ecosystem services under the factors of natural and human have great significance to formulate the "win-win" policy about regional development and ecological protection in Karst mountainous areas.This study selected the karst mountainous area as the study area and used the In VEST(Integrate Valuation of Ecosystem Services and Tradeoffs)model and the production-possibility frontier analysis method to evaluate the spatial and temporal variations of ecosystem services and analyze the tradeoff and synergic relationship between different services.The results showed that,1)From 1990-2010,in addition to the increase of soil retention,water yield,nutrient retention and carbon reserve in Karst mountainous area were decreased in different degrees.Among them,The average water yield decreased by 24.50 mm(2.47%),the average soil conservation amount roughly 29295.05 t/km2(39.43%)growth,the average carbon reserve decreased by 10.34 kg/km2(0.34%),the average nutrient interception decreased by 7.12 kg/km2(1.16%).2)Cultivated land and grass land had relatively balanced ecosystem service functions,forest land had three ecosystem service functions with a high capacity,The four ecosystem service functions of water areas were all relatively low,The water supply capacities of construction land and idle land were relatively high?In our study cultivated land and grass land had relatively balanced ecosystem service functions,the capacity of nutrient retention maximum were: 0.2659,0.2690,the capacity of water yield minimum were: 0.1623?0.1653;while forest land had three ecosystem service functions with a high capacity above 0.2.The capacity of water yield is highest 0.4867;The four ecosystem service functions of water areas were all relatively low all blow 0.2.The water supply capacities of construction land and idle land were relatively high were 0.1996,0.1731,while the other three functions were low,no more than 0.15,the carbon reserve capacity almost 0.3)The ecosystem service function has obvious gradient effect,the higher the altitude,the smaller the water yield,The average annual water yield of four gradients from low to high were: 1077.32 mm,947.28 mm,827.42 mm,799.29 mm;the higher the altitude,the carbon reserve and nutrient retention show the trend of decreasing fluctuation,The average annual carbon reserve of four gradients from low to high were: 2981.04 t/km2,3297.80 t/km2,3022.75 t/km2,2939.60 t/km2,and the average annual nutrient retention of four gradients from low to high were: 678.02 kg/km2,566.56 kg/km2,628.15 kg/km2,460.40 kg/km2;There was no significant change of soil conservation with elevation.the average annual soil conservation of four gradients from low to high were: 77926.57 t/km2,100627.01 t/km2,81485.69 t/km2,91442.87 t/km2?4)In spatial,water yield had tradeoff relationships with soil conservation capacity,nutrient retention,and carbon reserve;Soil conservation and nutrient retention also showed a tradeoff relationship;Carbon reserve had synergic relationships with nutrient retention and soil conservation.The increase of soil retention,nutrient retention and carbon storage were not conducive to the increase of water yield,According to the production possibility frontier curve of each ecosystem services: To achieve 20000 t increment of soil conservation,the reduction of water yield in different stages were: 80 mm,144 mm,208 mm;to achieve 100×102 kg increment nutrition retention,the reduction of water yield in different stages were: 59.18 mm,95.18 mm,131.18 mm;to achieve 1000 t increment of carbon reserve,the reduction of water yield in different stages were:3.38 mm,15.02 mm,26.67 mm.The increase of soil conservation does not take advantage of the increase of nutrient retention,to achieve 20000 t increment of soil conservation,the reduction of nutrient retention in different stages were: 80×102kg,49×102kg,42×102kg.Carbon reserve had synergic relationships with nutrient retention and soil conservation capacity,with the 1000 t increment of carbon reserve,the increment of soil conservation in different stages were: 45137.00 t,25346.00 t,5555.00 t,the increment of nutrient retention in different stages were: 61.29×102kg,100.67×102kg,140.05×102kg.5)The ecosystem services under the scenario of natural growth,economic development and ecological protection in Karst mountainous area are simulated,and the overall benefit of Karst mountain ecosystem is the best under the scenario of economic development.As we can see from the Standardized data based on ecosystem service scenario,Under the scenario of economic development,the total ecological services of Karst mountain area is the largest(2.2668),and the overall benefit is the best,under the scenario of actual situation and natural growth,the total ecological services were: 2.0279,2.0272,while the scenario of ecological protection have a minimum total services with 2.0000,the overall efficiency of the least.