Effects of Reintroduction of Fire into Fire Suppressed Coastal Scrub and Longleaf Pine Communities Along the Lower Gulf Coastal Plain

Abstract

The Northwest Florida coastal landscape consists of a mosaic of sand pine scrub, longleaf pine, and ecotonal communities. Fire suppression has altered the structure and composition of these communities. The effects of environmental variation and the recent reintroduction of fire on plant distribution and abundance across this landscape were investigated. Relative cover of herbaceous and woody ground cover species and density of sapling and canopy trees along with elevation, percent bare ground, percent canopy cover, and litter depth were determined in burned and long-unburned treatments for all community types. Canonical correspondence analysis (CCA) identified elevation and time since fire as the most influential environmental variables for species distribution and abundance. Species most closely associated with lower sites included Gaylussacia mosieri Small, Ilex glabra (L.) Gray, Kalmia hirsuta Walt., Magnolia virginiana L., Pinus palustrus P. Mill., Vaccinium myrsinites Lam., Aristida L. species, and Calamovilfa curtissii (Vasey) Schribn.. Species associated most closely with higher sites included Ilex vomitoria Ait., Quercus chapmanii Sarg., Quercus geminata Small, Quercus myrtifolia Willd., Vaccinium stamineum L., Baptisia lanceolata (Walt.) Ell., Cladonia Hill ex P. Browne species, Eriogonum tomentosum Michx., Rhynchospora megalocarpa Gray, and Yucca filamentosa L. Eight months post fire, burned sites had lower density of woody overstory and saplings compared to long-unburned sites. Herbaceous species richness did not differ between burned and long-unburned sites. Repeated prescribed fires during the growing season and direct seeding may be needed to promote flowering and establishment of additional herbaceous species.