Effects of exotic grasses on potential fine fuel loads in the groundcover of south Florida slash pine savannas

Invasive exotic grasses have been hypothesized to increase fine fuel loads, thereby increasing the frequency and intensity of fires. Most studies, how ever, have been conducted in habitats in which natural fires do not occur f requently. We investigated the effects of two invasive grass species, Imper ata cylindrica and Neyraudia reynaudiana, on potential fine fuel loads of s outh Florida slash pine savannas, which naturally experience frequent fires during the lightning season. Total above-ground biomass of fine fuels and litter biomass were greater in areas where exotic grasses were present than in nearby areas not containing these grasses. In addition, less above-grou nd biomass of native species was present in areas where N. reynaudiana was present. The increases in both potential total fine fuels and litter sugges t that exotic grass invasions can change fire characteristics, even in ecos ystems where fires occur very frequently.