Muskeg
From Wikipedia, the free encyclopedia
Muskeg is a soil type (also a peatland or wetland type called a bog) common in arctic and boreal areas. Muskeg consists of dead plants in various states of decomposition (i.e., peat), ranging from fairly intact sphagnum moss, to sedge peat, to highly decomposed muck. Pieces of wood such as buried tree branches can make up 5 to 15 percent of the peat soil. Muskeg tends to have a water table very near the surface. As well, the sphagnum moss forming it can hold 15 to 30 times its own weight in water, allowing the spongy wet muskeg to form even on sloping ground. Muskeg patches are ideal habitats for beavers, pitcher plants, agaric mushrooms and a variety of other organisms.[1]
Muskeg is wet, acidic, and relatively infertile which prevents large trees from growing, although stunted Shore Pine, Cottonwood, some species of Willow, and Black Spruce are typically found. It needs two conditions to develop: abundant rain and cool summers. A dead plant that falls on dry soil is normally attacked by bacteria and fungi and quickly rots; if however the same plant lands in water or on saturated soil it faces a different fate. Less oxygen is available under water so aerobic bacteria and fungi fail to colonize the submerged debris effectively. In addition, cool temperatures retard bacterial and fungal growth. These effects slow decomposition, and thus the plant debris gradually accumulates to form peat and eventually muskeg. Depending on the underlying topography of the land, muskeg can reach depths of thirty metres (100 ft) or more.
Superficially, muskeg resembles a plain covered with short grasses, and small stands of trees growing where land protrudes above the water table. Its benign grassland appearance invites the unaware to walk on it. However travelling through muskeg is a very strange and dangerous experience to the unaccustomed. Muskeg can grow directly on top of bodies of water, especially small ponds and streams. Because of the water beneath, the muskeg surface often ripples when walked upon. Thinner patches can allow large animals to drop through, becoming trapped under the muskeg and drowning. Moose are at a special disadvantage in muskeg due to their long legs, minimal foot area, and large mass; young moose are occasionally encountered in muskeg covered ponds submerged up to their torsos or necks, unaware that the ground was not stable enough for them to walk on.
Muskeg can be a significant impediment to transportation. During the 1870s, muskeg in Northern Ontario was reported to have swallowed a railroad engine whole when a track was laid on muskeg instead of clearing down to bedrock. Many other instances have been reported of heavy construction equipment vanishing into muskeg in the spring as the frozen muskeg on which the vehicle was parked thawed. Construction in muskeg-laden areas requires the complete removal of the soil and filling with gravel. If the muskeg is not completely cleared to bedrock then its high water content will cause buckling and distortion from winter freezing, much like permafrost.
