Responses of forest eco-service values to biotopes in the China’s Conversion of Cropland to Forest Program

The Conversion of Cropland to Forest Program is the largest ecological program of forest in China, which has significantly increased the forest coverage. However, it has been less effective than expected. Understanding the responding features of ecological benefits of forest to their biotopes, the relationships between the categories of ‘annual eco-service value of per unit area of forest’ (EV) and their biotope conditions is important for maximizing the ecological benefit of forest in the Conversion of Cropland to Forest Program. We analyzed the EV categories of three kinds of forest type in different biotopes, using the methods of ‘specifications for assessment of forest ecosystem services in China’. The result showed that the total EV (T_ev) varied in the range of 2.6–8.0 e⁴ RMBs hm⁻² a⁻¹. The EV categories performed differently among the forest types and the biotopes. Water conservation EV was the highest and nutrient accumulation EV was the lowest in all the four types of biotopes. Correlations between EV categories and biotope indicators were also analyzed. The T_ev of the ecological forest is mainly related to slope gradient, annual average temperature and latitude, which explained 20.1%, 14.3% and 12.6% of the variability of T_ev, respectively. The T_ev of the economic forest is mainly related to annual sunshine duration, altitude, slope gradient and annual average temperature, which explained 29.8%, 17.6%, 13.5% and 9.7% of the variability of T_ev, respectively. The T_ev of the shrubbery is associated with latitude and annual average temperature, which explained 49.9% and 22.6% of the variability of T_ev, respectively.