SREL Reprint 2480
Species selection trials and silvicultural techniques for the
restoration of bottomland hardwood forests
Kenneth W. McLeod
Savannah River Ecology Laboratory, University of Georgia, PO
Drawer E, Aiken, SC 29802, USA
Received 19 March 1999; received in revised
form 21 May 1999; accepted 7 September 1999
Abstract
Since 1990, a series of experiments has examined the appropriateness of 24 tree species for restoring a
bottomland and swamp forest in the delta of Fourmile Branch in the coastal plain
of' South Carolina, USA. In addition, various silvicultural techniques used to maximize the survival of tree plantings, have been appraised for effectiveness. While
the topographic relief on the delta is small (dm differences between most sites), it is sufficient to utilize woody species
with different flood tolerances. Hence, a diverse forest community can be established, using these elevation
differences. In the wettest sites where water persists virtually continuously and may be one to two
meters deep during
large flood events, only the most flood-tolerant species, such as
Taxodium distichum and Nyssa aquatica, can survive. These species will also survive very well at higher elevations, because the permanent water table
never fell below one meter deep. In sites that are not flooded, unless the entire swamp is flooded, several additional species can be used.
These include Fraxinus pennsylvanica, Carya aquatica and Quercus
lyrata. Finally, in slightly higher areas, Q. michauxii, Q
nuttallii and Q. phellos would have adequate survival. To minimize
herbivory and maximize survival, tree shelters should be used if herbivore pressure is high. The prime herbivore of concern is beaver. Thus, any
plantings that are frequently flooded may require protection. Other silvicultural techniques, including fertilization and
control of herbaceous and willow competition, were not essential to ensure growth and survival. Finally, survival
of the least expensive planting stock, bare root saplings, was nearly as good as balled and but-lapped stock. Thus, unless
absolute maximal Survival is required, bare root stock will produce good survival at a fraction of the cost. One critical
characteristic of the bare root stock is height, which must exceed the flood depth during the growing season.
In the case of the Fourmile Branch delta, this was at least 45-60 cm tall.
Keywords: Wetland restoration; Bottomland forest; Hydrology;
Savannah River; Pen Branch
SREL Reprint #2480
McLeod, K. W. 2000. Species selection trials and silvicultural techniques for the restoration of bottomland hardwood forests. Ecological Engineering 15:S35-S46.
