Soil texture, land-use intensity, and vegetation of Fort Benning upland forest sites
John J. Dilustro, Beverly S. Collins, Lisa K. Duncan, and Rebecca R. Sharitz
Savannah River Ecology Laboratory, PO Drawer E, Aiken, SC 29802
Abstract
Federal lands may harbor much of the diversity of upland pineoak-hickory
forests in the southeastern USA Fall Line Sandhills region. These forests
are managed throughout the region; species composition is influenced by
topography, soil composition, periodic natural and prescribed fires, and
forest harvesting practices. Our objective was to describe the canopy
and ground layer vegetation of upland sites at Fort Benning, Georgia that
are managed primarily for longleaf pine (thinned, burned at 3 year intervals)
and differ in soil texture (from sandy to clayey) and intensity of military
training (lighter dismounted infantry vs. heavier mechanized training).
We characterized surface soil texture and land-use disturbance of 32 sites,
each 400 m X 400 m, and asked if canopy and ground layer community measures
(species composition and richness, basal area, abundance) differed among
sites on the basis of soil texture or land-use. There was significant
interaction between land-use and soil texture, with a gradient of soil
texture (% clay) from clayey sites within light training areas, to sandy
sites in heavier training areas. Road-like features, including active
and remnant trails, roads, and vehicle tracks or trails were the most
frequent and abundant disturbance feature. Number of disturbance features
per site did not differ among land-use/surface soil texture categories.
Differences in ground layer and canopy composition among sites reflected
disturbance intensity; differences in canopy composition also reflected
the proportion of pine. Species richness of ground layer vegetation differed
among surface soil texture/land-use categories. There was a richness gradient
from heavily disturbed sites with clayey soil, through lightly disturbed
sites, to heavily disturbed sites with sandy soil. Our results suggest
upland pineoak-hickory forests at Fort Benning range from sandhills scrub
oak-pine to pine-hardwood to oak-hickory dominated forests, with greater
species diversity in the ground layer of clayey sites. Forestry practices
and disturbances associated with mechanized military training favor pine
dominance, and maintain open-site, successional or fire-tolerant species
in the ground layer. Although intense management toward pine monocultures
can reduce within-stand diversity, federal installations such as Fort
Benning may help conserve pine-oak-hickory forests in the rapidly developing
Sandhills region.
Key words: pine-oak-hickory forests, sandhills, Fort Benning,
soil texture, disturbance.
SREL Reprint #2650
Dilustro, J. J., B. S. Collins, L. K. Duncan and R. R. Sharitz. 2002. Soil texture, land use intensity, and vegetation of Fort Benning upland forest sites. Journal of the Torrey Botantical Society 129:289-297.
