Is carry-over of grass biomass between years important in determining savanna fire regimes?

Abstract

We show that the size of areas burned in three southern African parks is dominated by the amount of rainfall in the immediately preceding summer. Considering mean rainfall from two years previous changes r² values by <20%. We interpret this to suggest that carry-over of grass from one fire year to another is relatively unimportant. The implications of this are: i) the relation between fire frequency and intensity may not be a negative one, and ii) burning trials with a fixed fire frequency will not easily be able to discern frequency and intensity effects. We predict decreasing woody plant density with increasing fire frequency.

Keywords: carry-over, savanna, fire intensity, grass, rainfall

African Journal of Range & Forage Science 2006, 23(1): 81–83