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

~akareous Seepage Swamps
England sites mentioned abve, and individud
swamps held as many as 90 species in some cases.
Bedrock and surficial geolodc deposits through- Black ash, which is the most nutrient-demmdlout
most of the Northeast are low in base content. ing and least acid-tolerant ash species
a result, most swamps in 'his ''don are acidic 1980), is a conspicuous overstory dtssoGiah of red
and nutrient-- The majority of swamps demaple
in calcareous seepage swamps. ~~~~i~~
scribed thus far fall in that category. In several elm, white pine, and swamp white oak
areas of the No*heast, calcweous growdwater Or
are also common. Nearly 30 species of shrubs have
surface water derived fmm lhesbne, marble, or
been recorded at individual sibs; some of the most
lime-rich surficial deposits enters wetlands and has
include red-osier dogwood, aldera
dramatic effect on the composition and richness
Leaf buckthorn (Rhamnus alnifolia), shrubby
of the plant In Vemont~ cinquefoil (Potentilia fmtimsa), stiff dogwood
northern New Hampshire, and Maine, calcareous
(Cornus foemina), and meadowsweet. Ericaceous
swamps are typicdly dominated by white species are notably scarce, except for highbush
cedar (Thompson, personal comunication; Nowblueberry
(Metzler and Tiner 1992). Speckled alell,
personal communication; Davis, personal amder,
silky dogwood, common winterberry, swamp
munication), while in southern New England and
rose, poison sumac, and poison ivy are other corn-
New York, hemlock or mjxed conifer-hardwood formon
shrubs.
ests often predominate ('I!J. Rawinski, The Nature
Nutrient-rich conditions of caEcareous seepage
Conservancy, Boston, Mass., personal comunicaswamps
are most clearly reflected in the herb layer,
tion). Calcareous swamps dominated by red maple
which may include 60 or more species at a single
occur primarily in southern New England, southern
New Hampshire, the Lake Champlain basin,
site. Among the most frequently encountered are
and central and eastern New York.
lakebank sedge (Carex lacustris), tussock sedge
The Eastern Regional Office of The Nature
(Carex stricta), cinnamon fern, royal fern, and tall
Conservancy has compiled detailed floristic data meadow-rue. Crested fern, marsh fern, bluejoint
from at least 15 wetlands that it classifies as
grass, linear-leaf willow-herb (Epilobium kptosouthern
New England calcareous seepage phyllum), bedstraws, boneset (Eupatorium perfoliswamps
(Rawinski 1984). The species list labelled atum), water pennywort (Hydmty le amen'cam),
"calcareous" in Table 3.3 includes all of the species Swamp buttercup (Ranunnclus septentnbmlk),
recorded at five of these swamps where red maple and skunk cabbage are other common herbs.
was either dominant or codominant. The locations herbs seepage
of these red maple swamps range from southeast- not be seen as frequently as those above, but
are strong indicators of either groundwater dissetts
to northwestern Connecticut and adjacent charge or calcium-rich soils (~awinskl, ~ersonal
New York state.
communication). Groundwater indicator planta in-
While some calcareous swamps in the glaciated cludebristly-stalked sedge (carex k~taka), marsh
NO&heast oecur in seasonally flooded basins, the marigold, golden saxifrage (Chvsospknium
swamps described by The Nature Conservancy amefianum), purple-stemed angelica (~ngelica
typically occur at the headwaters, or along the atropu~urea), soft-leaf sedge (carex d-rma),
valley edges, of small streams where soils are water avens, fen orchid @Paris hselii), swamp
saturated by groundwater seepage for most or all saxifrage (Saxif~a Pe~ivanica), small purpleof
the year, but where surface flooding is infre- fringed orchid (Phtanthera PSY~~),
woodland
quent. The New York Natural Heritage Program horsetail (Equketum s~lvathm), and golden ragrecognizes
a red maple-tamarack peat swamp, wort (Semcio aureus). khst of these plank a .
which is floristically similar to the southern New scarce or absent from swamps lacking groundwa-
England seepage swamps, but which occurs in ter discharge. Calcicoles (Plants normally growing
poorly drained depressions fed by calcareous in cafcareous soils) found in these seepage swamps
ppundvvakr mid contains orgdc soil @sc]&e include fringed brome (Bromus cilktm), idad
1990). Calcareous seepage swamps tend to support sedge (Carex inter'or), yellow sedge (Carex fktva),
a much greater diversity of plant species than bulbous bittercress (Cardamine bulbosa), hemlock
seasonally flooded swamps laeking groundwater parsley (Conioselinun chirzense), tufted loosestrife
inflow mawinski, personal communication). Over (Lysimachia thyrsiflora), swa~np thistle (Cirsium
150 species were recorded at the five southern New muticurn), and globefl ower (Trollius bs). Bog
ern N~~ hi^^ through western ~ ~ ~ ~ ~ ~ h ~