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Descriptive information about the study area |
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Saltonstall ridge is a long
crescent-shaped basalt ridge in
East Haven, Connecticut, just a few kilometers north of Long
Island Sound. It runs mainly north-south while curving from
the NE to the SE. The top of the ridge is about 100 m above
the surrounding landscape and is about 300m wide at the
base. Lake Saltonstall, a water authority reservoir, lies to
the east of the ridge, inside the curve, and the Farm River
valley lies to the west. The rock that is now the ridge
intruded into the surrounding bedrock during the Triassic
period as a broad lava flow. The region subsequently was
downfaulted on the east and then overlain by deep
sedimentary sandstone rocks. Since then, Triassic erosional
processes have removed the sedimentary rock and left the
considerably harder basalt ridge we see today. The crest of
the ridge is several tens of meters wide and quite
plateau-like with the east and west slopes falling away from
the plateau quite steeply. Soils are very shallow and rocky,
primarily composed of rounded and angular basalt cobbles and
stones. Although direct outcrops of the basalt are
infrequent, the bedrock is within a meter of the surface
over much of the ridge.
The ridge is covered by a mixed deciduous forest with scattered hemlock. The hemlock was much more abundant until about 1987; since then, it has largely succumbed to an exotic insect pest—the hemlock woolly adelgid. Deciduous species are primarily sugar maple and oak on the west slope and a mix of oaks and hickories with sugar maple on the east slope.
The entire ridge is owned and
managed by the South Central Connecticut Regional Water
Authority as a public water supply protection watershed and,
secondarily, for timber production. Some saw logs are
removed and cull trees are sold to small wood cutters for
fire wood cutting. Timber is harvested selectively under a
strict management plan. An access road runs the length of
the summit.
Study Area
Our study area lies about 2 km
north of I-95 and 3-400 m north of a large water storage
tank on the ridge. The study area is laid out as a series of
adjacent, continuous transects across the ridge. Plot
numbering starts on the Farm River side (west) and goes east
to the edge of the Lake. The plots we are currently
re-measuring in 1999 were established in 1991 as part of
this same course at Yale. There are 30 plots along each
transect (though 29 were studied in 1991), each 10x10m, not
slope-corrected. The staked grid system is set up with the
stakes marking the center lines of each of the 4 adjacent
transects. Plot edges are determined as being within 5
meters of either side of the center line.
