Assessment Of Carbon Fixation Quantity In Phoebe Bournei Plantation Forests Using FORECAST Ecosystem Model

Evaluation of forest carbon sequestration potentials is important for designing forest management strategies to mitigate the effects of global climate change. As one of the important subtropical evergreen broad-leaved forest tree species, Phoebe has become a popular species for plantation forests in Jinagxi and Fujiang provinces. Currently, there were many reports on silviculture, nursery and biomass of Phoebe forests, but few on the carbon sequestration potentials unde different management practices. In this study, the forest ecosystem model, FORECAST was used to simulate the effects of different management strategies on carbon sequestration in phoebe forests. Data on forest biomass, stand density, light and soil nutrients, response curve under different site conditions were collected from field surveys or from published papers. After the model calibration and validation, FOREACST was run with various management scenarios including different planting densities, thinning intensities rotation lengths. The main conclusions are as follows:(i) The plantation density of 2500 trees/hm2 is appropriate. If the site conditions are relatively poor, higher densities should be chosen to maintain the sustainability of forest productivity.(ii) The thinning methods of low (15%) and moderate (25%) intensities should be used to achieve better results. The most appropriate thinning time and intensity need further simulations in a broader context considering protection of environment and habitat;(iii) The rotation length of 80 years is superior to shorter rotation (e.g.,20 years or 40 years). Rotation length is important for influencing forest carbon sequestration with a longer and higher carbon sequestration.(iv) Phoebe plantations has obvious role on soil improvement, especially on the poor site. As a hardwood species, Phoebe produces a large amount of decomposition litter and nutrients, which is important for maintaining high carbon sequestration.(v) Sustainable Phoebe plantation management can be significant not only to provide economic benefits, but also to maximize ecological services (eg., carbon sequestration capacity and the sustainability of forest productivity)...