Future forest dynamics under climate change, land use change, and harvest in subtropical forests in Southern China

Context Subtropical forests have and will continue to face tremendous pressure from various disturbances, which have the potential to alter forest composition, structure, and function. Forest dynamics relate to spatial patterns, ecological processes, and their interactions. However, integrating forest ecosystems and land systems has seldom been attempted in southern China. Objectives We explore the spatiotemporal response and trajectories of forest dynamics at different scales under climate change, harvesting, and land-use disturbances in the near future. Methods We simulated forest landscape dynamics by integrating a forest landscape model (LANDIS-II), an ecosystem model (PnET-II), and a land change model (CA-Markov) for 2010 to 2050. We identified changes in forest composition, aboveground biomass, and landscape patterns under individual and integrated scenarios, including a control scenario, climate change, harvesting, and land-use change for tree species, ecoregions, and forest types. Results For forest composition, the forest area continued to increase, and coniferous forests increased approximately 3.7 times that of broad-leaved forests. Harvesting reduced aboveground biomass, with a reduction of 30.3% in comparison to the control scenario. The integrated disturbances showed a greater impact on the forest landscape. Landscape fragmentation increased, showing that the patch density increased by 52.3% (control scenario), 46.2% (climate change), 118.4% (harvest), 55.0% (land use change) and 139.5% (integrated scenarios), respectively. Conclusions Our results suggest that climate change will contribute to forest growth, especially for coniferous forests. Harvesting will reduce forest area and aboveground biomass. The interaction between human activities and climate change contributes to diminished forest expansion and increased landscape fragmentation.