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

drica), bugleweeds, violets, and bedstraws
(Galium spp.).
Zone 11.Great Lakes and Glaciated
Allegheny Plateau
Zone I1 includes the greater part of New York
State, as well as northeastern and northwestern
Pennsylvania (Fig. 3.10). The white pine-hemlockhardwood
forest dominates upland habitats in
those sections where red maple swamps are most
abundant. The Lake Erie coastline falls within the
oak-yellow-poplar forest region, while the beechbirch-maple
forest predominates in eastern New
York and northern Pennsylvania (Fig. 1.3).
Red maple swamps in zone I1 commonly occur
over extensive glaciolacustrine and glaciofluvial
deposits (Van Dersal 1933; Stewart and Merrell
1937; Goodwin 1942; Shanks 1966; Huenneke
1982; Malecki et al. 1983). Bedrock in most of this
zone is shale, sandstone, or limestone (Fenneman
1938). Where limestone occurs, calcareous
swamps are common. Often, however, the influence
of underlying marl layers on soil pH and
nutrient status is diminished by overlying organic
deposits; hence, the flora of many swamps in Iirnestone
areas do not exhibit an enriched status
(Huenneke 1982; Malecki et al. 1983). Swamps
that developed over alluvial deposits or former bog
soils also are common in this region (Bray 1915;
Van Dersal1933; Goodwin 1942).
Early in this century, Bray (1915) identified two
major swamp forest associations in New York:
mixed conifer-hardwood swamp and hardwood
swamp. These two types, which have been recognized
in more recent literature as well, are described
briefly below
Mixed Conifer-Hardwood Swamps
These wetlands are distributed primarily from
the eastern Ontario Basin to the Adirondacks,
along the drainage divides of north-south valleys
of the Allegheny Plateau, and from the Syracuse
region east through the Mohawk River valley. Red
maple swamps described by Huenneke (1982) in
the southern Finger M es region and by Paratley
and Fahey (1986) in the Oneida Lake region are
examples of this community. Tree species that are
common in the mixed coder-hardwd swamps of
zone 11, namely, hemlock, white pine, yellow birch,
red maple, and elms, are also found in zone I
swamps. However, red maple assumes a less irnportant
role in many of the swamps in zone 11; frequently
it is codominant with evergreen species
(Van Dersal 1933). Although such mixed associations
occur in zone I, they are not as common as in
zone 11. Black and green ash frequently occur in
swamps near the Great Lakes. Black spruce, balsam
frr, and tamarack are found in mixed coniferhardwood
swamps of New York, both at higher
elevations and in cool lowlands. In northwestern
Pennsylvania, hemlock is the principal conifer in
this wetland type (Brooks and Tiner 1989); red
spruce (Picea rubens), tamarack, black spruce, and
white pine all occur in the mixed conifer-hardwood
swamps of northeastern Pennsylvania (Brooks
et al. 1987).
Hardwood Swamps
These forested wetlands, referred to as red maple-hardwood
swamps by the New York Natural
Heritage Program (Reschke 1990), are most abundant
in the western portion of the Ontario Basin
and in the Hudson River valley of New York (Bray
1915), but they occur throughout zone 11. Historically,
they were dominated by American elm, but
with the decline of this species because of Dutch
elm disease, the relative importance of other tree
species has increased (Huenneke 1982; Malecki
et al. 1983). Some of the most common trees besides
red maple are green ash, black ash, swamp
white oak, basswood, and butternut (Jugktns cinerea).
White pine and hemlock are rare components,
while northern white cedar, tamarack, and
balsam fir are absent (Stewart and Merrell 1937;
Goodwin 1942; Malecki et al. 1983). Pin oak, shingle
oak (Quercus imbricaria), red oak, bitternut
hickory, and shagbark hickory (Carya ovata) are
common in hardwood swamps in the Ontario Basin
west of Rochester, N.Y. (Stewart and Merrell1937,
Goodwin 1942), and at the glacial limit in western
Pennsylvania (Phillips 1971).
Brooks and Tiner (1989) recognized two common
hardwood swamp associations in northwestern
Pennsylvania. The frrst includes red maple,
American elm, green ash, black ash, and swamp
white oak, while the second includes red maple,
yellow birch, and black cherry. In the Pocono region
of northeastern Pennsylvania, red maple and yellow
birch are the dominant broad-leaved deciduous
wetland trees @rooks et al. 1987).
The composition of the shrub straturn does not
vary greatly among the various swamp associations
in zone 11. Highbush blueberry, common winterbeny,
spicebush, vibmums, black chokebemy
(Amnia nelamrpa), speckled alder, American
witch-hazel, and poison sumac are cormnonly en-