Aboveground carbon sequestration rate in alpine forests on the eastern Tibetan Plateau: Impacts of future forest management options

Abstract

Alpine forests in the eastern Tibetan Plateau are important ecological barriers in the upper reaches of the Yangtze River. However, due to continuous high-intensity harvesting, a large number of plantings, and the complete harvesting ban measures in recent decades, the forest tree species and age cohorts have become relatively homogenous, and the biodiversity and ecological functions have been reduced. To design effective forest management options to optimize forest structure and increase carbon sequestration capacity, Mao County was selected as the study site and six forest management options (harvesting, planting) of different intensities were tested using the LANDIS-II model to simulate and compare the differences in forest aboveground carbon sequestration rate (ACSR) between these options and the current management option over the next 100 years. Our study indicates that (1) the different harvesting and planting intensities significantly changed the ACSR compared to the current management options; (2) different communities responded differently to the management options, with the ACSR differing significantly in cold temperate conifers and temperate conifers but not in broad-leaved trees (p<0.05); and (3) a comprehensive consideration of forest management options at the species, community and landscape levels is necessary. Our results suggested that implementing a longer harvesting and planting interval (20 years) at the study site can maximize forest ACSR. This study provides an important reference for evaluating the ability of forest management options to restore forest ecological functions and increase carbon sequestration capacity and for selecting effective forest management programs in the eastern Tibetan Plateau.