Abstract:
The CASA model was used to calculate the net primary production (NPP). Based on the carbon cycle process model, the soil organic carbon storage in Qinling-Daba Mountain area was estimated from 2000 to 2017, and the net present value (NPV) method was used to estimate the economic value of soil organic carbon in 2015 and 2017, and the differences in soil carbon values under different land use forms were analyzed. The results indicated that on the time scale, the NPP of vegetation in Qinling-Daba Mountain area showed a trend of increasing firstly and then decreasing. The average NPP value of vegetation reached its peak in 2015. On the spatial scale, the NPP of vegetation in Qinling-Daba Mountain area was different in space. The overall trend of high in the middle and low on all sides, mountain area higher than plain is presented. The spatial distribution of soil organic carbon content is affected by the net primary productivity of vegetation and the mineralization intensity of soil. In the pattern of low southeast, the high value area is mainly concentrated in the middle part of the Qinling Mountains and parts of the Daba Mountain area. The net present value method is used to estimate the value of soil organic carbon in different scenarios of Qinling-Daba Mountain area in 2015 and 2017. Under different carbon prices and discount rates, the value of organic carbon varies greatly, and the higher the discount rate and carbon price, the higher the value. The value per unit area under different land use types was also obtained. The total value of the forest and grassland is higher, and the value of the unit area of the unused land is higher. Incorporating the discount rate and carbon price into the estimation of the value of soil organic carbon can be more realistic, and also provides a certain theoretical basis for the government to set a reasonable carbon price.
