Influence of thinning & prescribed burning on future forest fires (AGU 2021)
Channel: Sam Rabin
Date: 20/12/2021

(Presented at AGU 2021, New Orleans)

Over the coming decades, climate change likely will intensify fire regimes in certain regions, posing a threat to ecosystem functioning that could even result in shifts to new ecosystem types (such as from forest to savanna). In addition to the impacts from habitat and biodiversity loss, such changes could threaten climate mitigation goals as the land carbon sink is reduced there. At the same time, expansion of and development in the wildland-urban interface (WUI) threatens to bring more and more people, property, and infrastructure into contact with dangerous wildland fire events. It is critical that fire be managed in a way that minimizes risk to human health and well-being without affecting the important role it plays in many ecosystems.

Thanks to their ability to simulate large geographic regions across long time periods, dynamic global vegetation models (DGVMs) could be helpful in designing fire management programs for long-term goals of ecosystem function and risk reduction. However, thus far they have not been put to this use. 

In this work, we introduce a prescribed burning module—the first in a DGVM—to the LPJ-GUESS vegetation model. Focusing on two regions (Eastern Europe and the Iberian Peninsula), we compare the effectiveness of prescribed burning and mechanical thinning on various aspects of the fire regime under two climate change scenarios through the end of the 21st century. 

We find that prescribed burning, by reducing fuel load, reduces fireline intensity; this suggests that what wildfires do occur could be more easily controlled. While this would be a benefit for human health and well-being, it comes with the tradeoff of increased fire emissions, which could contribute to respiratory problems. Mechanical thinning reduces fireline intensity by as much or more while also reducing emissions. While these results should not be considered definitive, as we tested only very simple and stylized management treatments, this work shows the potential of DGVMs in exploring fire management options under climate change.