Evaluation Of Forest Ecosystem Service Change In NFPP Area In Northeast China From 1992 To 2015

Since 2000,the Northeast China began to implement Natural Forest Protect Projection（NFPP）.The aim of NFPP is to find a balance between forest protection and economic development.Therefore,how to assess the effect of NFPP accurately has become an important scientific issue,as reasonable forest planning and management strategies can promote both ecological restoration and economic development.This study evaluated different ecosystem services based on land cover maps and normalized difference vegetation index（NDVI）from 1992 to 2015 in Northeast China.CASA model,USLE model and In VEST model were applied to simulate the NPP,soil conservation and water retention of each year.We used CV（coefficient variation）,MK（Mann-Kendall test）,TS（Theil–Sen Median trend）,Hurst and linear regression to count the variation trend of different ecosystem services.To quantify the climate and human impact on difference ecosystem services,the Pearson correlation and residual analysis were used.The purpose of this study is to characterize the changing trends of different ecosystem services and the effects of NFPP on ecosystem services scientifically.The results of this study are as follows:（1）From 2000 to 2015,the NFPP gained initial achievement as the forest area increased in northeast China.The increased forests are mainly derived from cultivated land,grassland and sparse vegetation.In addition,due to the development of agriculture and the implementation of the policy of returning farmland to grassland,the transformation of grassland and cultivated land are relatively fierce,and the transformation area of grassland and cultivated land are mainly located at the Songnen Plain.（2）The implementation of NFPP has improved the quality of ecosystem as the vegetation cover increased in NFPP area.In addition,after the implementation of NFPP,the stability of vegetation coverage in NFPP area has been improved（the area of stable state has increased by 42.98% compared to that of 1992-1995）.And the changing trend of vegetation coverage is mainly increasing.（3）After the implementation of NFPP,different ecosystem services have been improved.In the NFPP area,the annual change of average NPP average showed a growing trend from 2000 to 2015,with an increasing rate of 0.0016 a^-1.For spatial distribution,the NPP showed an improving trend with 76.14% of NFPP area from 2000 to 2015.The annual change of average soil conservation showed a decreasing trend from 1992 to1999(-1.17a^-1)and an increasing trend from 2000 to 2015(14.58 a^-1).The annual change of average water retention showed a decreasing trend from 1992 to 1999(-5.36^-1),while an increasing trend from 2000 to 2015(8.43 a^-1).92.86% of the NFPP area showed improvement of water retention spatially.（4）In the NFPP area,the ability of different ecosystem services is better than that in the non-NFPP area.Areas with higer NPP,better soil conservation ability and better water retention ability are mainly located in Daxing’an Mountains,Xiaoxing’an Mountains and Changbai Mountains with forest cover.While in Hulunbeir,Songnen Plain and Chifeng,the mean ability of NPP,soil conservation and water retention are relatively poor.Grassland,cultivated land and sparse vegetation are the main land usage types in this area with poor ecosystem services.（5）There are synergistic relationships among NPP,soil conservation and water conservation in Northeast China.The synergistic relationship between soil conservation and water conservation is very significant.The relatively important area of integrated ecosystem services only accounts for 16.83% in Northeast China.These important areas are mainly distributed in the NFPP area.This study assessed the ecosystem service in Northeast China comprehensively and systematically.In the future,the government should strengthen the implementation of NFPP in northeast China.Different management and plan should be made according to the actual situation.In addition,in order to protect the environment and promote economic at the same time,the development of forestry economy is also important.