Relationships between plant biomass and cover in the ground cover layer of longleaf pine forests at Fort Benning, GA

Abstract

Interest in restoring longleaf pine (Pinus palustris Mill.) ecosystems has recently grown but little information is available for estimating biomass in the highly diverse ground cover layer of longleaf pine forests. Aboveground biomass-cover relationships in the ground cover were examined by growth form (shrubs/tree seedlings, vines, graminoids, legumes, forbs, ferns) in five longleaf pine stands ranging in age (5, 12, 21, 64, and 87 years) and forest structure at Fort Benning, GA. Cover was visually estimated and live biomass was determined through destructive harvests. Total live biomass in the ground cover layer ranged from 28 to 171 g m-2. Linear relationships were observed but different models were required for different growth forms and stands. The increase in biomass with increasing cover was greatest in the youngest stand for all growth forms except shrubs/tree seedlings, where the slope coefficient was highest for the 12-year-old stand. For forbs, the two oldest stands demonstrated a greater increase in biomass with increasing cover than the 12- and 21-year-old plantations. Live, herbaceous, graminoid, and dead biomass decreased linearly with increasing basal area. Results suggest that percent cover can be used to obtain a rapid estimate of biomass in the ground cover layer of longleaf pine forests.