UNDERSTORY RESPONSE TO SPRINGTIME PRESCRIBED FIRE IN 2 NEW-YORK TRANSITION OAK FORESTS

Portions of two south-central New York transition oak stands received 0, 1 or 2 springtime prescribed fires between 1980/1981 and 1984. Obse rvations 8-12 years later showed that forb richness, forb and shrub co ver, and the importance values of forbs relative to shrubs increased i n areas receiving one or two fires. Fagus grandifolia, Dennstaedtia pu nctilobula, Gaultheria procumbens and Trientalis borealis exhibited sm all, but detectable increases in importance values in burned areas. Th e importance values of Quercus rubra, Kalmia latifolia and Viburnum ac erifolium decreased in burned areas. Areas receiving greater intensity fires contained taller tree regeneration and greater shrub cover, but no important changes in community composition could be attributed to fire intensity. An apparent relationship between rhizome depth and pos t-fire competitiveness of dominant perennial forbs and shrubs suggests the importance of below-ground morphological traits on survival and r ecovery following fire. Overall, the 12-year, post-bum cover and densi ty of understory vegetation increased in burned areas and in areas rec eiving greater intensity fires, however, community composition remaine d largely unaffected by these springtime prescribed fires.