Modeling Subtropical Forest Changes under Climate Change and Close-to-Nature Silviculture: Is There a Tipping Point in an Uncertain Future in Southern China?

Subtropical forests face pressure from both rapidly changing climate and increasing harvest activity in southern China. However, the interactive effects of various spatial processes on forests are not well known. The objective of the present study was to answer the question of how forest aboveground biomass (AGB) changes under alternative climate change and harvesting scenarios and to determine whether there will be a tipping point for forest AGB before 2300. Our simulation results show that, although total forest AGB did not reach a tipping point before 2300 under possible climate change and harvesting scenarios, the slope of the total forest AGB showed a decreasing trend around 2100 and 2200. Moderate climate warming was conducive to AGB accumulation, except for in the high emissions Representative Concentration Pathway (RCP8.5) scenario. Our results also indicate that timber harvesting is adaptable to the accumulation of biomass under climate change scenarios. Harvesting intensity was a key variable affecting forest AGB more than harvesting frequency. Our findings will help develop more sustainable forest management strategies that can adapt to potential climate change scenarios, as well as determining the effectiveness of implementing alternative forest harvesting policies.