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

$able 2+4. Soil dnzinuge classes jafier Wright and Sautter 2 979).
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bmage class
Characteristics
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Excessively drained
BrightIy colored; usually coarse-textured; rapid permeability; very low
water-holding capacity; subsoil free of mottlesa
Somewhat excessively drained Brightly colored; rather sandy; rapid permeability; low water-holding
capacity; subsoil free of mottles
Well drained
Color usually bright yellow, red, or brown; drain excess water readily,
but contain sufficient fine material to provide adequate moisture for
plant growth; subsoil free of mottles to a depth of at least 91 cm
Moderately well drained
Generally any texture, but internal drainage is restricted to some degree;
mottles common in the lower part of the subsoil, generally at a depth of
46-91 cm; may remain wet and cold later in spring; generally suited for
agricultural use
Somewhat poorly drained Remain wet for long periods of time due to slow removal of water;
generally have a slowly permeable layer within the profile or a high
water table; mottles common in the subsoil at a depth of 20-46 cm
brly drained
Dark, thick surface horizons commonly; gray colors usuilly dominate
subsoil; water table at or near the surface during a considerable part of
the year; mottles frequently found within 20 cm of the soil surface
Very poorly drained
Generally thick black surface horizons and gray subsoil; saturated by
high water table most of the year; usually occur in level or depressed
sites and are frequently ponded with water
"See the section on soils in this chapter for a discussion of the significance of mottlcs.
detailed account of water level activity in seasonally
flooded and seasonally saturated red maple
swamps. The following discussion of water levels
is based on their findings.
General Patterns
Water levels in red maple swamps are highly
dynamic; marked variations among seasons,
years, and swamps are typical. Figure 2.7 shows
the general pattern of water level activity in seasonally
flooded red maple swamps, based on
Lowry's (1984) study. From an annual high in the
spring (April-May), water levels at all six sites
declined to their lowest points in late summer or
early fall. The low point commonly occurred in
September, but ranged from July to October, depending
on the amount and distribution of precipitation
in the particular year. High water levels
ranged from 20 cm above the surface to 20 cm
below in most years, but low water levels were far
more variable. In the wettest year of the study
(1979), three of the swamps had water at or above
the surface during the entire measurement period
(mid-April to mid-December); water levels at the
other sites remained within 30 cm below the surface
in that year. In the driest years of the study
(1980,1981), water levels at all sites dropped more
than 50 cm below the surface, and at some sites a
subsurface depth of 1 m was exceeded.
Differences in water levels among sites were
greatest at the end of the summer, when water
levels were lowest (Fig. 2.7). The greatest differences
were observed in the driest years. Lowry
(1984) concluded that these differences in low
water levels resulted from differing amounts of
groundwater inflow at the various sites, a factor
determined by hydrogeologic setting and soil type
(Bay 1967; OBrien 1977). In nearly every year,
water levels were clearly influenced not only by
total precipitation, but also by distinct weather
patterns or unusual events (e.g., heavy rains associated
with Hurricane Belle in August of 1976;
exceptionally high rainfall in May of 1978 and
June of 1982; abnormally high, well-distributed
rainfall in 1979; and consistently low rainfall
throughout 1980 and 1981).
Inspection of the water level hydrographs
(Fig. 2.7) revealed that most of the sites studied by
Lowry (1984) met the definition of seasonally
flooded (Table 2.3), while the others were seasonally
saturated. The soils at all of those sites were
very poorly drained. In the transition-zone stud%
all of the wetland stations-poorly drained and
very poorly drained-were seasonally saturated;
except for brief rainfall events, surface water was
absent during the growing season in most years.
Figure 2.8 provides a 3-year record of water
levels at 2 of the 54 wetland stations monitored