Current and future carbon stocks of natural forests in China

Abstract

Natural regeneration of forests is the most cost-effective and most technically straightforward strategy to mitigate climate change. Natural forests account for 71% of China’s forested area, but their carbon stocks and sequestration potentials remain unclear. Here, we compiled data from 762 natural forest sites across China and found that natural forests had a carbon stock of 9.40 ± 1.45 Pg C in 2010. When naturally regenerated to the over-mature stage, existing natural forests can additionally sequestrate 8.67 ± 6.93 Pg C in the next two centuries, accounting for 48% of the carbon carrying capacity of the natural forest ecosystem in China, i.e. 18.07 ± 6.78 Pg C. Future carbon sequestration potential in natural forests is dominated by the tree layer at 6.88 ± 6.87 Pg, followed by the shrub layer at 1.02 ± 0.55 Pg, floor layer at 0.72 ± 0.74 Pg and herb layer at 0.05 ± 0.10 Pg. The natural forests are expected to achieve 70% of their future carbon sequestration potential by 2100. We also note that assisted regeneration via tree planting can play a significant role in natural forest restoration, as the carbon densities of natural and planted forests are rarely significantly different at the same age under 60 years old. Therefore, the preservation and expansion of natural forests is the key strategy for achieving long-term carbon sequestration.