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

Zhuo Wu,Erfu Dai,Wenchuan Guan

doi:10.3390/su12176992

Abstract

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.

Highlights

Global climate change poses a huge threat to forests, and there remains great uncertainty regarding the extent of future climate change, which will greatly depend on current human activities [1,2]
Total forest aboveground biomass (AGB) increased under all climate and harvesting scenarios from 2010 to 2300 (Figure 2)
The results demonstrated total forest AGB gradually approaching the maximum forest AGB but without reaching the tipping point until 2300

Summary

Introduction

Global climate change poses a huge threat to forests, and there remains great uncertainty regarding the extent of future climate change, which will greatly depend on current human activities [1,2]. Many forests are facing pressure from both rapidly changing climate and increasing timber harvest activity [4]. Global warming has affected forest productivity [5], tree species abundance [6], and spatial distribution [7], while forest loss represents a more pervasive land transformation due to excessive harvesting globally [8]. Such changes have been substantial, but the interactive effects of various spatial processes on forests remains unknown. China has been implementing policies, such as the Natural Forest Conservation Program [10] and the Returning Farmland to Forest Program [11]

Objectives

Results

Discussion

Conclusion