A Marsh? A Bog? A Swamp? A Fen?

Wetlands can be a bit baffling. What is a bog? Is it different than a fen? And what the heck is muskeg? The Northern Boreal Mountains ecoprovince is a great place to start in answering these questions.

A region of mountains, plateaus, and densely forested valley bottoms, the borthern boreal mountains are also characterized by lowland wetlands.

Two wetland types are common: bogs and fens. In addition to water, both are characterized by peat – poorly decomposed vegetation – at least 40 cm deep.

Often referred to as muskeg in northern boreal and arctic regions, bogs and fens provide important ecosystem services. They provide habitat for species like the threatened woodland caribou. Bogs and fens also store carbon and help mitigate climate change.

So what’s the difference?

Bogs store and release water to and from the surrounding land, but are not connected to a system of lakes or streams. Bogs are nutrient poor and generally have low plant diversity as a result.

Fens, on the other hand, are connected to slow, but flowing water of small lakes and streams. According to Ducks Unlimited, in a fen, “water sources have been in contact with nutrient-rich surface and/or groundwater making fens more productive and biologically diverse than bogs.”

In the northern boreal mountain ecoprovince, looking at what grows in a wetland can also give you a clue to whether it is a bog or a fen.

In a northern boreal bog, you can expect to find stunted Black spruce, Labrador Tea, Cloudberry, Leatherleaf, Lingonberry, and Sphagnum moss.

In a northern boreal fen, you may also find black spruce, as well as white, but also expect to find tamarack.Sweet Gale, willows, Buckbean, sedges and fen mosses make up the low, shrubby layers.

So what about marshes and swamps? Ducks Unlimited Canada has excellent resources.

Featured image by Gordon McKenna via Flickr