Seldom is there a time of year when beast or human can
travel through or over the fen in the Fletcher
Creek Ecological Preserve in
Puslinch Township.
At the end of January the snow cover on the fen
was about 35 cm deep. With the freeze thaw cycles that we have been
experiencing the snow was very crusty. Not hard enough to support a person on
foot but on cross country skis or snow shoes you didn’t sink at all. Also
taking advantage of this crusty snow were some deer making their way out over
the fen with their tracks visible in a number of places.
Other than at times like this, deer are not likely
to travel onto the fen because of the very soft wet soils. The sparse
vegetation growing on the fen in the spring and summer is also not likely to be
at the top of their menu choice.
What is a fen anyway? A fen is one of the four types of wetland and they
are very rare in Southern Ontario. A fen for many of us might look like a wet
field. By definition a fen is a wetland that has water flowing through it all
year but the water has a low amount of nutrients in it and thus the vegetation
that can grow in it are only plants that have adapted to grow in wet and low
nutrient environments.At our fen the
vegetation is mostly sedges, rushes, some grasses and mosses. We might want to
call this fen a marsh as marshes have water flowing through them as well but
the water in a marsh carries higher levels of nutrients and you find plants
like cattails, smartweeds and other succulent emergent water plants. Marshes
are highly productive wetlands with plants that grow quickly and can recover
from disturbance fairly well. The plants
in fens grow slowly and disturbances in fens may last for countless years
before they can heal themselves.
The fen in the Fletcher Creek Ecological Preserve (FCEP) is likely the only fen in the watershed of the Hamilton Conservation Authority. It is a couple of hectares in size. The water flowing through our fen is low in nutrients because it comes from springs that are found in and around FCEP. These spring waters are one the major sources of Spencer Creek. The springs come from the aquifer known as the Galt moraine that lies at the northern boundary of FCEP. The rain water flows down through the gravelly hills of the moraine, a glacial deposit, and some of this water comes back to the surface as springs. When the water comes out of the ground it is clean and pure, low in nutrients and 10 degrees Celsius all year round. The creeks draining these springs in the FCEP never freeze in winter because the water starts off so warm.
The fen at FLCP is special in its own way. It
sits on top of about 2 meters of peat. Anything trying to travel over the fen
will simply sink most of the time. The plants are sparse and their root network
is not strong enough to support the weight of large mammals. This peat has been
accumulating in a shallow depression left on the landscape after the glaciers
left this area around 16,000 years ago. Over this time what started out as
shallow lake has filled in with organic debris, peat, and today we have our
fen.
There is a
small creek that meanders through the fen and it carries a lot of water but
water also travels
through the entire fen, just slower. Think of the fen as a
giant sponge about 300 m or so across and 2 meters thick. Wow!
The creek here is special too. It is kind of
floating on the fen as it travels through it. Creeks are usually found at the
bottom of a ravine or valley. Our creek here has a visible current at the
surface but it is running over 2 meters of very very saturated muck. What looks
likes a creek to your eyes is almost bottomless to your foot. Once the creek
leaves the fen and travels through the forest it has a hard gravelly bottom
like most creeks do.
I can sort of hear the first deer say “Oh Muck, watch out”
to the other one but the warning was too
late. As they headed towards the
forest I think the second one was heard saying, “ Oh you just had to take the
short cut, now look at us, we smell like Muck.”
In other areas of the fen where the deer travelled the creek
is much narrower and the deer stepped across from one snow bank to another.
Here the deer might have gotten a little too confident about the first step. If
you are up in Puslinch Township and you see some dirty deer you now know why.
They will likely stink for weeks.
In the Hamilton area we have only one fen, lots of marshes,
lots of treed swamps and one true floating mat bog in Copetown.
Bruce Mackenzie
Director of Customer Services
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