Ecosystem services value change in Qinglong County from dynamically adjusted value coefficients

Ecosystem services value is changing with the change in natural and economic conditions. This paper adjusted the "unit area of ecosystem services value of China's terrestrial ecosystem" put forward by Xie Gaodi et al from national scale to county scale. Then vegetation net primary productivity (NPP) was used to form functional adjustment factor, and adjustment factor of ability to pay and adjustment factor of willingness to pay used to calculate economic adjustment factor to adjust the above results. The paper then constructed a dynamic evaluation model for ecosystem services value and calculated dynamic changes in each ecosystem service value coefficient (value per unit area) in Qinglong County for 2003-2012. Finally, the paper evaluated ecosystem services value for the recent decade, revealed the principles of dynamic change in terrestrial ecosystem at county scale. The functional adjustment factors of forest land and garden plot were set as 1.032 and 0.903, respectively, due to they were the main land use types of biological productivity. Other land use types were without functional adjustment factors. Calculation results indicated that functional adjustment improved distinction degree of vegetation types of different coverages by amending equivalent factor value with functional factor of ecosystem services. The adjustment factor of ability to pay was ratio of GDP per person of Qinglong County to national mean GDP per person, while adjustment factor of willingness to pay was calculated with Engel Coefficient. The combination of the adjustment factors of ability to pay and willingness to pay (economic adjustment factor) fluctuated in an upward trend in time. The study results showed that each ecosystem service value coefficient fluctuated with an improving trend for different land use types in Qinglong County in 2003 2012. The ecosystem services value improved by 4.443 billion Yuan in the decade, at an average annual rate of 3.78%. Compared with previous static evaluation model, the results were more favorable, especially for small-scale counties that are extremely sensitive to economic policy. The analysis also revealed the mechanism of dynamic changes in ecosystem services value with better effects.