Error analysis of estimating terrestrial soil organic carbon storage in China Soil Carbon Cycle of Phyllostachy edulis Plantation in Huitong Region, Hunan Province Characteristics and Controlling Factors of Soil Organic Matter Turnover Processes in the Subtropical Mountainous Area, South China Analysis of soil CO2 efflux in Populus and Ulmus pumila planting shelterbelts in arid region,China