A bog is typically a Sphagnum-dominated
wetland, highly acidic in nature, with little influence by calcium due to surface water or
groundwater flow. A fen is a wetland heavily influenced by calcium, often through springs.
The surrounding drumlin hills consist of pulverized material from igneous rocks of the
Canadian Shield to sandstone and limestone or dolomite, and the immediate area sits on top
of the Lockport dolomite layer (the same bedrock layer that caps Niagara Falls).
Furthermore, several of the wetlands in the area have marl layers deposited in their soil
strata from the time that they were open, mildly alkaline lakes with calcium-depositing
algae. Yet water inflow is currently quite low, reducing the buffering and oxidizing
nature of the soil. Zurich bog could never be a strongly acidic bog, nor could it be a
fen. It is, however, an interesting mix of both. The vegetation provides the evidence for
this, such as the presence of two trees of different pH preferences, the calciphile Thuja
occidentalis (northern white cedar) with the boreal acidic wetland tree Picea
mariana (black spruce). Many examples of this sort of pH-based biodiversity exist
here.The plant diversity of this bog is
also influenced by the successional phases contained within. Large enough to contain
several distinct habitats, this wetland has late successional bog forest along the margins
and surrounding the island drumlin with red maple (Acer rubrum), common yew (Taxus
canadensis), hemlock (Tsuga
canadensis), black ash (Fraxinus nigra), yellow birch (Betula lenta),
spicebush (Lindera benzoin), gold thread (Coptis groenlandica) and cinnamon
fern (Osmunda
cinamomea); early successional bog forest with tamarack (Larix
laricina), black spruce,
highbush blueberry (Vaccinium corymbosum), northern white cedar (Thuja
occidentalis), and Sphagnum spp.;
open sphagnum bog several species of Sphagnum, leatherleaf (Chamaedaphne
calyculata), Labrador tea (Ledum
groenlandicum), purple pitcher plant (Sarracenia
purpurea), narrow and round-leaved sundews (Drosera
intermedia and D. rotundifolia), cranberry (Vaccinium oxycoccus), Scheuchzeria
palustris, and several orchid species; and quaking sedge meadow/marsh/open pools
with Scirpus spp., narrow-leaved cat tail (Typha
angustifolia), reed grass (Phragmites australis), water lily
(Nymphaea odorata), purple pitcher plant, narrow-leaved sundew, posion sumac (Toxicodendron
vernix), wax myrtle (Myrica gale),
and water willow (Decodon verticillatus). Even the isolated upland area on the
island contains sizeable individuals of hemlock, black cherry (Prunus serotina),
red oak (Quercus rubra), beech, white pine (Pinus strobus),
tulip tree (Liriodendron tulipifera), sugar maple, and herbaceous species like
white and red trillium (Trillium grandiflorum & T. erectum), false
solomon's seal (Smilacina racemosa), grape fern (Botrychium
virginianum), and indian cucumber root (Medeola
virginiana). Upland forest surrounding the bog is at a much earlier successional
stage due to easier access to logging, and some portions of the sphagnum bog have been
historically mined for peat, both of which add to the diversity of the site.
Finally, the diversity of the Zurich Bog is
influenced by ancient relicts and recent arrivals. The temperate forest in the uplands and
surrounding the bog, typical of most of central & western New York State, is of more
recent origin, developing here from southern migrations over the last several thousand
years due to glacial retreat and warming of the climate. In contrast, much of the wetland
and bog forest flora is relictual from an earlier, colder period from relatively soon
after glacial retreat. Such plants are typical of boreal and tundra conditions, like black
spruce, tamarack, leather leaf, labrador tea, and cranberry. And the late-successional bog
forest is typical of transition forests in the Adirondack Mountains, northern New England,
the Northern Great Lakes, parts of southeastern Canada, and cooler parts of the Alleghany
Plateau. Eventually, without further disturbance, all of this bog will become this type of
forest.
The grassy meadow with a pond at center is
actually the quaking mat over Mud Pond. The low hill just to the right is the drumlin
island in the bog. Note the large drumlins just beyond the meadow. This photo was taken
from the top of another large drumlin, Brantling Hill.
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