Savannah ecosystems, and regions with extreme wet or dry seasons were found to be the most sensitive to changes in fire frequency. Trees in regions with moderate climate are more resistant. Repeated fires also cause less damage to tree species with protective traits like thicker bark.
These effects only emerge over the course of several decades: the effect of a single fire is very different from repeated burning over time. The study found that after 50 years, regions with the most extreme annual fires had 72% lower wood area - a surrogate for biomass - with 63% fewer individual trees than in regions that never burned. Such changes to the tree community can reduce the forest’s long-term ability to store carbon, but may buffer the effect of future fires.
“Planting trees in areas where trees grow rapidly is widely promoted as a way to mitigate climate change. But to be sustainable, plans must consider the possibility of changes in fire frequency and intensity over the longer term,” said Dr Adam Pellegrini in the University of Cambridge’s Department of Plant Sciences, first author of the paper.
Read more at: University of Cambridge
Savannah Fire at Africa's Kruger National Park (Photo Credit: Corli Coetsee)