Research Highlights - Savanna Fire

Fire is one of the major drivers of vegetation patterns and associated biodiversity in African savannas. Using Light Detection and Ranging (LiDAR) imagery collected by the Carnegie Airborne Observatory (CAO) in the Kruger National Park (KNP), South Africa, we compared high-resolution woody vegetation height surfaces for a series of experimental burn plots. These 7-ha plots have been subjected to fire in different seasons and at different frequencies, as well as no-burn areas, for 54 years, making it one of the oldest and largest fire experiments in Africa.

We found that more frequent fires reduced woody vegetation cover more than less frequent fires, and dry-season fires reduced woody vegetation more than wet-season fires. Spring fires from the late dry season reduced woody vegetation cover the most, and summer fires from the wet season reduced it the least. These differences were most pronounced for vegetation below 4 m, but were still observable at 7.5 m. Since both fire frequency and fire season influenced patterns of vegetation three-dimensional structure, managers of savannas should consider fire frequency and fire season in concert to achieve specific vegetation structural objectives (e.g., countering bush encroachment or allowing trees to escape the fire trap and emerge as tall trees).

Images, from top to bottom:

- Ground view of one experimental burn plot in Kruger
- 3-D perspective of 2 burn plots derived from CAO data.