EFFECTS OF LATE GROWING-SEASON AND LATE DORMANT-SEASON PRESCRIBED FIRE ON HERBACEOUS VEGETATION IN RESTORED PINE-GRASSLAND COMMUNITIES

We compared the effects of late dormant-season and late growing-season prescribed fires on herbaceous species in restored shortleaf pine-(Pi nus echinata) grassland communities in the Ouachita Highlands of weste rn Arkansas. Herbaceous species richness, diversity, and total forb an d legume abundance increased following fire. Late growing-season burns reduced distribution and abundance of panicums (primarily Panicum bos cii, P. dichotomum, and P. linearifolium) while late dormant-season bu rns increased Panicum distribution and abundance. Density of legumes ( such as Stylosanthes biflora) increased following frequent or annual d ormant-season fires. However, season of fire influenced the distributi on and abundance of fewer than 10 % of the species. Fire plays an esse ntial role in pine-grassland communities by creating and maintaining o pen canopy conditions that perpetuate understory herbaceous plant comm unities.