The distribution of tree species in steepheads of the Apalachicola River Bluffs, Florida
Abstract
Steephead ravine forests of the Apalachicola River Bluffs region of northern Florida contain tree species that are widespread in the Southeastern Coastal Plain and species that are highly endemic, such as the Florida yew, Taxus floridana. We sampled woody vegetation in three ravine systems within the Apalachicola Bluffs and Ravines Preserve (Liberty Co., Florida). We used transects randomly located along north-facing and south-facing slopes, as well as transects along north-facing slopes that contained adult individuals of T. floridana. Slope position (lower slope, midslope, and upper slope) greatly affected important species composition and densities. In contrast, aspect of steepheads had little influence on the densities of most species. American beech (Fagus grandifolia), southern magnolia (Magnolia grandiflora), and a number of evergreen understory species were more abundant along north-facing slopes containing T. floridana than along random north-facing slopes. North-facing slopes containing T. floridaria, with their characteristic mesic midslope areas, represent a unique subset of north-facing slopes along steepheads of the Apalachicola River Bluffs. The discontinuous distribution of such north-facing slopes within ravine systems potentially results in a discontinuous distribution of T. floridana.