A combination of special conditions
sustains a bog. These include a high water table, lots of
sunlight, a nutrient-poor soil, and most importantly,
Water levels are close to the
surface during the winter when there is a large
amount of rain. Excess water flows through the
surface layers of the bog and out at the drain
located near King Edward Avenue at the southeast
Starting normally in late
April or early May, the rainfall decreases so that
evaporation is greater than precipitation and the
water level starts to drop. This continues through
the summer, until September or early October when
the fall rains start. The level then rapidly rises
as the bog is filled. From November onwards the
water levels are generally high and fairly
critical time in the bog is late summer when water
levels are at their lowest. In the core area of the
bog this may be 50 or 60cm below the surface. On
the periphery it may be much lower, as much as
100cm below the surface.
existence of the bog depends on one plant, sphagnum
moss. This thrives in soil of low oxygen content
and with poor nutrient availability.
stems are hollow and it holds large amounts of
water, helping to keep the water table close to the
surface. It does not rot easily and the dead shoots
remain attached to the living plant forming a giant
"sponge". Thus the peat below the surface and the
growing sphagnum may form continuous structures
which can be hundreds of years old.
also acidifies water as it absorbs nutrients, and
this makes decomposition still more difficult.
Nutrients are locked up in the peat, which does not
decompose, thus keeping the nutrient levels low.
The only source of new nutrients is rainfall and
this water is quite pure.
A bog is an open place with
lots of sunlight, but with a very acid soil, low
oxygen and low nutrient contents. Most plants
cannot grow in these conditions. However a number
of specialised plants including sundew, Labrador
tea, and cloudberry, have evolved to take advantage
of these special conditions where they have little
competition from normal forest plants.
conditions change, and bog plants are in
competition with forest or marsh plants, then
inevitably the bog plants die out. This is
currently happening in Camosun Bog in areas that
have not yet been restored