Effects of fire-generated gaps on growth and reproduction of golden aster (Pityopsis graminifolia)

J. S. Brewer, University of Mississippi
W. J. Platt, University of Mississippi
J. S. Glitzenstein, University of Mississippi
D. R. Streng, University of Mississippi

Abstract

This study examined the effect of fire-generated gaps on the growth and reproduction of a rhizomatous forb, Pityopsis graminifolia (golden aster). Two growing seasons after the creation of artificial fire generated gaps, we observed that these gaps were mostly devoid (<1% cover) of the dominant grass, wiregrass (Aristida beyrichiana), and that ramet densities of golden aster were an order of magnitude lower in gaps than in adjacent undisturbed patches. Ramets of golden aster occupying gaps were an order of magnitude larger (dry mass), produced five times as many tillers, and were more likely to bolt than ramets located outside gaps in not recently burned or January- burned vegetation. Bolting and tillering were only slightly greater (~10%), however, inside gaps than outside gaps in May-burned blocks four months after the May fires. We therefore conclude that golden aster potentially performs better within fire-generated gaps than within dense vegetation dominated by wiregrass, at least in years without lightning season (May) fires. We suggest, however, that such differences between gaps and dense vegetation likely have little effect on the long term performance of golden aster in pine savannas frequently burned in May.