Variable impacts of forest treatments on carbon and mortality following disturbance

Increases in the frequency and severity of climate-sensitive disturbances like wildfire, drought, and insect outbreaks pose an imminent threat to Earth’s forests, including their status as a net carbon sink. Forest treatments including thinning and prescribed fire are increasingly viewed as key tools for mitigating disturbance impacts, but their efficacy in stabilizing carbon stocks and reducing mortality, especially for drought and insect outbreaks, remains uncertain. Moreover, we have limited understanding of whether the moderating effect of forest treatments provides a net benefit to vegetation carbon stocks, or if the initial carbon loss required to implement treatments outweighs potential reductions in carbon losses during subsequent disturbance. Here we conduct a systematic meta-analysis of published literature to understand how thinning, prescribed fire, and combined treatments impact survival and carbon stocks following wildfires, droughts, and insect outbreaks. We found that treatments improved survival following wildfires, but had only marginal impacts on survival following drought and insect outbreaks. While thinning had a modest positive effect on carbon stocks following wildfire, treatments generally reduced carbon stocks following drought and had no impact following insect outbreaks. Overall, our findings suggest that the benefits of forest treatments for vegetation carbon stocks are limited, especially following drought and insect disturbances. These findings have important policy implications for carbon credit programs.

Duke Scholars

Author Jacob Levine Biology