Soil erosion control degree of the project of converting farmland to forest in mountainous areas at China’s Southwest border: A case study in Mangshi, Yunnan Province

Abstract

There have been few in-depth quantitative studies on soil erosion control and the ecological effects of land use changes. Soil erosion is the first eco-environmental problem particularly in mountainous areas. A major problem in the conversion of farmland to forest is to control soil erosion and improve ecological environment and thus to improve land use sustainability. We report results of calculation and analysis on soil erosion from converted farmland parcels in city of Mangshi (near the SW frontier of China) and the surrounding areas before and after the nine-year (2000-2009) project of converting farmland to forest. There was increased water conservation effect, as a result of decreased soil erosion. The average erosion modulus of the farmland returning to eco-friendly uses decreased by 5,535.59 t/km(2)center dot a and the control degree of soil erosion modulus reached 71.00%. The increased soil erosion after the returning in the typical sample area "did not drop, but increased" as the terraced fields decreased but sloping farmland increased and yet woodland decreased.