Impact of site management on changes in soil carbon after afforestation: A review

Abstract

Afforestation and forest management can increase carbon stocks and account for emission reduction according to the Kyoto Protocol. Site management has important effects on the accumulation of soil carbon after afforestation. This review examines the effects of site management, including soil disturbance, fertilization, thinning, weed control, harvesting and controlled burning, on soil carbon dynamics in plantations, based on recent published results. Soil disturbance can enhance soil carbon losses, with whole ploughing causing the most and disking the least loss of soil carbon. The effects of fertilization and thinning on soil carbon are inconclusive. Weed control can prevent the carbon input from above-ground residue and root turnover and increase soil temperature and soil erosion, which in turn reduces the amount of carbon on the soil surface. Soil carbon decreases with the increase of harvesting intensity and the retention of harvest residue can significantly enhance the accumulation of carbon in the soil. Controlled burning before afforestation has a short-term benefit for soil carbon, but it is not beneficial to the sequestration of soil carbon over the long term. Future studies should focus on investigating the long-term impact of site management practices, especially soil fertilization and thinning, on carbon, identifying the response of major functional pools of soil carbon to management practices, understanding the dynamics of soil nitrogen pools and their role in long-term soil carbon sequestration, as well as quantifying soil carbon processes under different climate conditions and site management scenarios using models.