Ecology of Red Maple Swamps in the Glaciated Northeast: A ...

Red maple swamp with an herb layer dominated
by cinnamon fern (Osmunda cinnammaa). This is the
most common species of fern in northeastern
swamps.
(Table 3.3). At any single site, however, a few species
usually predominate. In the tree layer, the
average number of species recorded per swamp
(sources in Appendix A) is about four (range 1-9).
In southeastern New England swamps, red maple
alone may compose as much as 90% of the relative
density and relative basal area (Lowry 1984). In
other parks of the Northeast, other tree species
frequently are better represented.
The shrub stratum in most red maple swamps
consists of a small number of common species
whose relative importance may vary widely from
site to site (Little 1951; Ehrenfeld and Gulick
1981; Braiewa 1983; Lowry 1984). The number of
species per site reported in the literature ranges
from 1 to 15 (sources in Appendix A). Up to 28 species
of shrubs and vines have been found in individual
red maple swamps fed by calcareous seepage
(The Nature Conservancy, Boston, Mass.,
unpublished data).
As few as one to three species commonly make
up the majority of the shrub stems in an individual
swamp. In Rhode Island, for example, the relative
density of sweet pepperbush averaged 53% (range
3-91%) at nine sites studied by Braiewa (1983) and
Lowry (1984). This species dominates the shrub
layer in many New Jersey red maple swamps as
well (Ehrenfeld and Gulick 1981; Ehrenfeld 1986).
Common winterberry (Ikx verticillata) composed
nearly 50% of the shrub stems sampled in two red
maple swamps In central New York (Eleed 1968).
At other sites, species such as highbush blueberry,
Table 3.3. Flora of red maple swamps in the glaciated Northeast. Zone locations are shown in Ftg. 3.10.
Species listed in the zone columns were reported from acidic swamps or swamps of unknown base
status;plants listed in the calcareous column (C) were reported from swamps fed by calcareous seepage.
Sources for this list are cited in Appendix A. Data for Zone Vare too few to be listed.
- -- ----- -- - - --- - - - - --
Zone
- - ---- Zone
Speciesa I I1 I11 IV C" SpeciesR I I1 I11 IV @"
n888
Abh balsrarnea ealsam fr)
Aaer mgundo (boxelder)
Acer mbrum (red maple)
Acer saccharinurn (silver maple)
Aaer saccharum (sugar maple)
Amelanchier arbom
(downy serviceberry)
Amlumhier aznodert9k
(oblong-leaf serviceberry)
Arnelanchier X intermedia
(swamp shadbush)
Betula alleghaniensis bellow
birch)
Betulu lenta (black birch)
X X X X Betula papyrifem (paper birch)
X X Betula populifolia (gray birch)
X X X X X Carpinuscaroliniana(b1ue
X X X beech)
X X X X Carya cordiformis (bitternut
hickory)
X X Carya laciniosa (big shellbark
hickory)
X X Calya ovata (shagbark hickory)
Carya tomentosa (mockerraut
X hickory)
Chamaeqpnris thyodes
X X X X X (Atlantic white cedar)
X X X
X X X X
X X X X X