Woody regeneration in and around aging southern bottomland hardwood forest gaps: Effects of herbivory and gap size
C.-A. Holladay1, C. Kwit*, and B. Collins
Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA
Abstract
We examined long-term impacts of mammalian herbivores and canopy gap characteristics
on woody plant establishment and growth within six size classes of canopy
gaps created in 1994 in a southern bottomland hardwood forest. Woody stem
composition (1996, 2004) and height (2004) were assessed in and out of
white-tailed deer (Odocoileus virginianus) and swamp rabbit (Sylvilagus
aquaticus aquaticus) exclosures in gap centers, and in additional
plots in gap centers, edges, and beneath adjacent forest canopy. Herbivory
did not influence vegetation patterns. Composition was more homogenous
in 1996 than in 2004, both in gap centers, and along the gap center—forest
understory gradient. Composition differed among gap sizes (oaks were more
prevalent in larger gaps) and with distance from gap centers (wind-dispersed
trees, wind- and animal-dispersed trees, and oaks typified gap centers,
gap edges, and forest understory, respectively). Seedlings and saplings
were tallest in the smallest gaps and gap centers, intermediate on gap
edges, and shortest in the forest. Maintaining low deer densities could
continue to minimize mammalian herbivore effects on woody regeneration
in this bottomland hardwood forest system. In addition, management for
canopy openings in a variety of sizes could promote woody vegetation heterogeneity
and regeneration of desirable tree species.
Keywords: Bottomland hardwoods; Canopy gaps; Gap partitioning;
Herbivory; Natural regeneration; Oak regeneration; Seedling establishment
and dynamics
*Corresponding
author at: Department of Botany, Miami University, Oxford, OH 45056, USA.
Tel.: +1 513 529 4263; fax: +1 513 529 4243. Email address: kwitc@muohio.edu
(C.Kwit).
1 Present address: Department of Biology, P.O. Box 32027,
Appalachian State University, Boone, NC 28608, USA.
SREL Reprint #2929
Holladay, C.-A., C. Kwit and B. Collins. 2006. Woody regeneration in and around aging southern bottomland hardwood forest gaps: Effects of herbivory and gap size. Forest Ecology and Management 223(1-3) 218-225.
