Soil heterotrophic respiration and its temperature sensitivity in different-aged orange plantations in Three Gorges Reservoir area of China Effect of bamboo leaf biochar addition on soil CO2 efflux and labile organic carbon pool in a Chinese chestnut plantation. Decomposition characteristics of maize and wheat straw and their effects on soil carbon and nitrogen contents Soil biochemical characters of Pinus koraiensis and Pinus sylvestriformis plantations under different elevated CO2 concentration Effects of fertilization on seasonal variations soil CH4 uptake fluxes in Chinese chestnut stands