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Niagara
Issues - Art Park Area http://www.mobot.org/plantscience/ResBot/niag/ |
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Niagara
Issues - Art Park Area The Artpark area is
located at the northern terminus (the mouth) of the gorge of the Niagara
River on the New York State side (eastern shore), below the Niagara
Escarpment. This area has a deep lineage of cultural history which has been
recognized on the state and federal level. The purpose of the following
posting is to explore with digital images the surprising hydrological
richness and complexity of this area, especially in winter when the water is
frozen and the least obscured by tree foliage, and when features may be
outlined by snow against the dark, moist and brown soil. Displayed are water
features both within the gorge walls and down on the plain of Lake Ontario at
the base of the north-facing Niagara Escarpment. The walls of the gorge on
the American side face west. They are in shadow longer relative to the
western, Ontario, gorge wall, throughout the morning, but receive the
afternoon sun, when the Canadian wall is in shadow. This regime seems to
favor a richer development of vegetation on the west gorge bank, rather than
the east bank, which also is subject to the desiccating power of the
prevailing winds. The calcareous caprock and strata lie above and between
layers of sandstone and shale, which appear to be relatively sterile and are
less pervious or impervious to the migration of groundwater. The distinctive
fracturing of calcareous strata, and their vulnerability to the action of
acids that occur naturally in precipitation tend to enlarge these fractures,
and to promote rapid runoff from the soil surface on the flat region
dissected by the Niagara River gorge. This tends to promote desiccation as
well and is a factor in the vegetative species components and plant
communities distinctive to both gorge walls. |
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Seepage and surface
runoff is part of the experience of the Niagara gorge. One striking component of the collection
of unique natural features of the Niagara area is this sopping landscape
immediately down on the lake plain at the base of the Escarpment. A similar
development occurs in Ontario with seeps and springs below Brock's Monument,
and which continue in adjacent cultivated areas in the ditching and moist
hedgerows of which Swamp White Oak (Quercus bicolor) may be observed. One can see the extent to which such runoff
has been modified at Artpark through time. The outflow of Fish Creek, that
wends its way above the Escarpment but debouches below on the lake plain
after diving below soil level at the golf course area above the village of
Lewiston, under the Robert Moses Parkway and perhaps the spoil area down on
the lake plain, may be seen in the following images. Almost downstream
several tens of yards of the Fish Creek outflow, is the natural ravine of a seasonal stream (name unknown to
this author), whose upper reaches are now underground, and only the outflow
is visible. At the northern boundary
of Artpark, at the edge of the parking lot is another modified stream, the
outflow pouring over the shaley substrates that compose most of the rather
tall lower river banks on both sides of the Niagara. North of this, on
private property is a curious natural outflow, perhaps the aboriginal aspect
of the banks along Artpark's western boundary, at the shoreline, is a display
of what might be called sheet seepage so rich that a distinctive plant
community based on dense mats of calcareous-seep loving moss Didymodon
tophaceus has grown for such a long time that the lowest reaches of the mats
covering the river bank are turned to stone.
At the suture between a
curious knoll of isolated bedrock, presently called Oak Hill due to its
distinctive forest rich in Oak and Hickory species, at least on its western
face, and the spoil area filling in the area between the Escarpment and its
southern boundary, occurs a pool that was probably once more extensive. Perhaps originally the
areas at the bases of the Escarpments on the lake plain adjacent to the
Niagara river were swamps, perhaps even white cedar swamps. The striking elevation of Oak Hill, called
here Scoville's Knoll from historic references to this feature from the
1860's, rising above such a swamp, together with its unusual forest of dry
species, aroused the respect of native peoples, such that a distinctive
burial construct was made there. It is suggested here
that some of this outflow may be artesian in nature: the point of origin for
some of this water may derive from the plain dissected by the Niagara River
gorge, south or upstream of Artpark, that migrated north and down through
fissures in bedrock to emerge from underground on the lower plain. The presence of the
White Cedar, a species of swamps in the seemingly most unlikely habitat of
the exposed calcareous caprock may be explained in part by the seepage
present nearly year round in the seepage associated with those strata. The interesting presence
of Phragmites and Purple Loosestrife, two of the classic invasive species and
nightmares to managers of natural wetlands, occurs in intimate association
with seepage and runoff. It is curious that these species avoid the margins
of the Niagara river, but not so any pooling of water in the ditches and
quiet outflows of the lake plain. |