REGENERATION OF THE SHRUB GAYLUSSACIA BACCATA AND ASSOCIATED SPECIES AFTER LOW-INTENSITY FIRE IN AN ATLANTIC COASTAL PLAIN FOREST

The upland shrub community of the New Jersey Pine Barrens maintains strong compositional and structural stability despite frequent low-intensity fires. To determine the mechanisms by which individual species respond to fire, regrowth of vegetation was monitored for 3 years after fire at a burned site, and at a nearby site that had not been burned. At both sites, experimental treatments simulated various physical aspects of fire, including clipping of stems, removal of leaf litter, and application of fertilizer. Both fire and clipping were followed by multiple resprouting and enhanced growth of the dominant shrub, Gaylussacia baccata, suggesting that sprout growth is controlled by correlative inhibition of adventitious buds. By contrast, neither fertilizer nor litter removal had a significant impact on G. baccata. Other species were only observed at very low numbers, and appeared to act independently of either fire or experimental treatments. Recruitment from seed was not observed in any treatment at either site, despite reports of a large soil seed bank. Thus, compositional stability is maintained through a large reserve of dormant buds on the dominant species, and through a lack of opportunities for associate species. This stability is precarious, however, depending strongly on fire frequency and intensity.