The Impact Of Forest Resource Change On Forest Ecosystem Service Function Based On Invest Model

Forest ecosystem and its service function cannot be replaced,maintenance and management of benign circulation of forest ecosystem is to maintain the basis of human survival and development.For the development of human beings,access to valuable resources,constantly changing the surface environment,showing a different land use.Land use change is an important driving force for the change of forest ecosystem services.The analysis of regional forest land resources and other land use changes and their impact on the forest ecosystem services is of great significance to promote the regional ecological environment construction and forest sustainable management.Therefore,this study takes Xichuan County,the headquarter of the Middle Route Project of South-to-North Water Diversion Project,as an example,using data of 2004 TM,2009 TM,2014 GF1.With the support of PIC and Arcgis10.0,the forest land resources and other land use changes were analyzed from 2004 to 2014.And the forest ecosystem services(water conservation,water purification and soil conservation)were quantitatively evaluated by using the In VEST model.The results are showed as follow:(1)From 2004 to 2014,woodland,construction land and water area increased,.And that,the evolution trend of forest land,woodland,shrub land and nurs ery garden was consistent with the overall evolution pattern of forest resources.Howe ver,suitable for forest,non timber forest land,unwoodland showed a decreasing trend.In the spatial distribution,forest land was mainly distributed in the northern mountain ous area,with the high altitude,the steep slope,and farmland and construction land w ere mostly distributed in southeast area,with the low altitude,the relatively gentle slo pe.(2)During 2004 to 2014,the change of ecological environment quality of Xichuan was mainly driven by the policy and the residents' pursuit of maximizing the benefits.The Government has made great efforts to afforestation.In the middle and lower reaches of the Yangtze River Shelter belt Project,the project of returning farmland to forest and ecological public welfare forest construction,the forest coverage rate,large area cultivated land,suitable forest land and no standing woodland have beenconverted into forest land.(3)With the changes of forest land resources,the forest ecosystem service function has the corresponding significant change.In the past 10 years,the water conservation function of the county has been reduced by 19%,the forest water purification function has been increased by 29% and the soil conservation function has increased by 6%.The function of water conservation,water purification and soil conservation in forest ecosystem was positively correlated with forest cover in 10 years,showing the pattern of spatial distribution pattern of north and south.(4)The ecological service function of each forest type was as follows: the amount of water conservation per unit area decreased,the function of water purification continued to increase,and the function of soil conservation increased first and then decreased.Comparing the ecological service function of the five forest types,the service function of forest land was the strongest,followed by shrubbery and sparse forest land.(5)During the past 10 years,the conversion of cultivated land into closed forest land,conversion of cultivated land into closed forest land,suitable forest land and non-stand forest land into closed forest land,conversion of cultivated land into undeveloped forest land is the main land use change type which leads to the change of regional ecological service function.(6)In the future planning to maintain the water quality of the important areas(northern)to protect,while avoiding the largest contribution to the southeast of the destruction of pollutants.For the northern mountainous areas with poor conditions,the strategy of "marginalization" can be adopted.For the terrain ups and downs larger,more scattered areas of the central region,should be a reasonable layout of the new residential location,so that the contractor near the new settlements.For the terrain of the southeastern region,can take "anti-marginalization" strategy.