The Effect Of Sloping Land Conversion Program On Forest Carbon Sink In Yunnan Province

Since 1999,the Sloping Land Conversion Program(SLCP)was piloted in Shaanxi,Gansu and Sichuan provinces,opening the prelude to the SLCP in China.As the largest payments for ecosystem services in developing countries,the central and local governments in China mainly invested in special fiscal transfer payment funds for the SLCP in areas with severe ecological degradation.The program attempted to increase the local forest and grass cover through afforestation in barren hills,closing hills for afforestation,and returning farmland to forest to improve the local ecological environment.According to the statistics,the national SLCP fiscal expenditure has reached 511.2 billion yuan,with project tasks covering 338666.67 km~2by the end of 2019.China's SLCP has contributed approximately25%of the biomass carbon sink in global carbon sequestration in 2000–2010,which showed new ways and hopes for us to make scientific evaluation on the effectiveness of the implementation of the project.Under the background of such a huge investment scale and the global promotion of increasing forest carbon and reducing emissions,reasonably assess the effectiveness of fiscal expenditure on the Sloping Land Conversion Program in providing forest carbon sink is conducive to the development of forest carbon sinks in China and the implementation of a new round of the Sloping Land Conversion Program.This paper firstly sorts out the domestic and foreign literatures,finds out the deficiency of the existing evaluation research on the effect of Sloping Land Conversion Program and the theories and methods that can be used for reference in the calculation of forestry carbon sink,and finally determines the research entry point.Using the MODIS Vegetation Cover Type(MCD12Q1)time-series datasets,we calculated the forest carbon sink of various counties(cities or districts).Based on the detailed analysis of the financial expenditure and forestry carbon sink of returning farmland to forest in yunnan province,the impacts of SLCP fiscal expenditure on forest carbon sink were empirically evaluated by the Least Squares Dummy Variables Method(LSDV).Considering that natural environmental,social,and economic conditions vary greatly among different districts and counties in Yunnan,there will be different policy implementation effects.The study introduces individual dummy variables and uses the interaction between individual dummy variables and the key explanatory variable of fiscal expenditure to explore regional differences in the effect of SLCP implementation.Furthermore,considering the particularity of the forest growth,the increase of the forest carbon sink may be self-dependent,i.e.vegetation growth is largely affected by initial forest resource endowment,which may explain the differences in efficiency.Therefore,to investigate the effects of policy implementation,we introduced the first-order lagged variable of forest carbon sink to the model to remove the influence of the initial forest endowment on forest carbon sink.Through empirical analysis,the results show:(1)The research results indicate that a 1%increase in fiscal expenditure on the SLCP yielded a 0.0364%increase in forest carbon sink.However,the effects of SLCP fiscal expenditure on forest carbon sink differed greatly in different areas because of the diversity of the natural environments,forest resource endowment,and government policies.(2)Further studies showed the existence of path dependence in forest carbon sink growth,with previous forest carbon sinks affecting the results of investment in the present.If the initial forest endowment was not considered,the effectiveness of fiscal expenditure on the SLCP in providing forest carbon sink would have been overestimated.(3)This study argues that,to improve the efficiency of SLCP fiscal expenditure in Yunnan Province,more investment should be made in regions with positive regression coefficients that have passed the significance t-test,such as Diqing Tibetan Autonomous Prefecture in the northwest,Baoshan City in the west,Honghe Hani and Yi Autonomous Prefecture in the south and Wenshan Zhuang and Miao Autonomous Prefecture in the east.