Bogs and Fens

IMG_0074bogBogs are usually in isolated pockets, and covered in sphagnum moss, known as "quaking mats" . Walking in these is dangerous because a person can easily fall through the moss and there is nothing to grab onto to come back out. Bogs have very acidic waters. There are people who fell through the moss thousands of years ago and became red and "pickled"- they are known as "bog people".

According to the Ontario Ministry of Natural Resources and Forestry, which leads wetland evaluations and programming in Ontario, "Fens are Peatlands that are poorly drained, but slow internal drainage does occur. Dominant vegetation is sedges, but shrubs and sparse, short tree growth may be present. Waters are circumneutral or only slightly acid. Three basic types are found. (a) Graminoid Fen - Open, sedge covered fen, with less than ten percent (10%) cover of shrubs or trees. (b) Low Shrub Fen - Open fen dominated by shrubs such as leatherleaf and dwarf birch less than 135 cm high. c) Treed Fen - Canopy cover more than ten percent (10%), usually tamarack, and usually not of merchantable size. " We can generalize that in central and northern Ontario fens are very similar to bogs; they are sphagnum dominated, but are less isolated with some movement of water, and therefore with more nutrients that would support some tree species like Tamaracks or black spruce. Cotton grass that likes extremely acidic waters is not dominant in a fen but is often found throughout bogs, as are pitcher plants, sundews, and other sedges.

Fens of southern Ontario, the Carolinas and a few rare instances at the southern edge of The Land Between zone near the dolomite and limestone, are often more alkaline and result not so much from isolation and the consequent formation of carbonic acid, but from seepage areas and/or the upward movement of groundwater. These fens are often flat areas that are moist and dominated by sedges; and they may have soils that are very fine and "clayey" known as Maarl, which are tiny calcareous particles or deposits.

But overall both bogs and fens have very few plant species (low diversity) because of the acidity and/or lack of nutrients in these systems.

Spotted turtles and Blanding's turtles like these habitats. OLYMPUS DIGITAL CAMERA

2 Replies to “Bogs and Fens”

  1. I live in Centreville Ontario along county Rd. 27. I have been told that I have a Fen on my property along 27. We are about to have road work for transmission line pole starting this spring. I feel that my fen is in danger. What should I do for protecting it? Its always been a special place for me when I am out walking my property. I’d like to do what is best for its protecting for the future. Thank ‘s for the info you have provided thus far. Heather Montrose

    1. Hi Heather,
      The first thing to do is get in touch with the local OMNRF office to see if your wetland is registered as a provincially significant wetland and/or if it has been evaluated. If it has not been evaluated, you can ask the Natural Heritage Information Centre of the OMNRF in Peterborough, and/or the local OMNRF office if there are records of species at risk associated with the wetland. If not, then I would get a local biologist who is willing to donate time perhaps to do an inventory and see if there are any rare plants/animals there….If any of these exist I am sure the road crews/municipality and Hydro One, if notified. will accommodate changes to protect what they can, but unfortunately, Hydro One use for transmission lines trumps most of the legislation to protect lands.

Comments are closed.