Effects of simulated nitrogen deposition on soil active carbon pool and root biomass in Neosinocalamus affinis plantation, Rainy Area of West China Soil Carbon-budget Mechanism in Different Origin Stands on the West Slope of Zhangguangcai Mountain Vertical distribution of soil active carbon and soil organic carbon storage under different forest types in the Qinling Mountains. EFFECT OF INTENSIVE CULTIVATION ON THE CARBON POOL OF SOIL IN PHYLLOSTACHYS PRAECOX STANDS