PARENT SESSION
Poster Session #29: Plant Ecology: Environmental controls.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Vegetation, nitrogen mineralizaion and soil texture of Ft. Benning, Georgia upland forest sites.

Dilustro, John^*,1, Collins, Beverly, Duncan, Lisa, Sharitz, Rebecca, ¹ University of Georgia, Aiken, SC, 29802

ABSTRACT- Upland forests at Ft. Benning are used for military training and managed primarily toward a longleaf ecosystem. We used an experimental approach to compare military use (heavier vs. lighter) and forest management treatments [4 combinations of burning (2 year cycle vs. 4 year cycle) between sites on sandy and clayey soils (32 sites total). We conducted a vegetation survey for baseline plant community structure and measured soil texture on all sample sites to evaluate effects of prior land use. There was a gradient of soil texture (% clay) from clayey sites within light training to sandy sites in heavier training areas. Species richness of ground layer vegetation differed among soil texture/land use categories; there was a richness gradient from heavily disturbed sites with clayey soil, to heavily disturbed sites with sandy soil. Laboratory incubations for soil nitrogen mineralization suggest mineralization on these sites is influenced by soil texture. Initial extractions for NH₄ were greater on clayey (1.09 g N/g soil) than on sandy (0.59 g N/g soil) soil. After 84 days nitrogen extractions showed the same pattern with clayey soil extractable NH4 (2.99 g N/g soil) greater than on sandy sites (1.16 g N/g soil). Understanding the interactions among these land use practices with differing vegetation and soil texture can guide management practices to enhance forestry and military use goals.

KEY WORDS: disturbance, vegetation, nitrogen