Bog

Mer Bleue Bog, a typical peat bog, in eastern Ontario

Carnivorous plants are often found in bogs. Capturing insects provides nitrogen and phosphorus, which are usually scarce in such conditions.

Abogis awetlandwherepeatbuilds up. Peat is layers of deadplantmaterial—oftenmosses,in most cases,Sphagnummoss.It is one of the four main types of wetlands. Other names for bogs includemire,quagmireandmuskeg.

Frequently, as the illustration on the right shows, they are covered inEricaceousshrubs rooted in the Sphagnum moss and peat. The gradual buildup of decayed plant material in a bog forms acarbon sink.

Bogs occur where the water at the ground surface isacidicand low innutrients.In some cases, the water is entirely fromprecipitation,in which case they are (rain-fed). Water flowing out of bogs has a characteristic brown colour, which comes from dissolved peattannins.

In general, the low fertility and cool climate results in relatively slow plant growth, but decay is even slower because of the saturated soil. So, the amount of peat increases. Large areas of landscape can be covered many meters deep in peat.Bogs have a distinctive group of plant and animal species and are of high importance forbiodiversity,particularly in landscapes that are otherwise settled and farmed.

World's largest peat bog

The world's largest peat bog is in theCongo (Brazzaville).It is as big asEngland.The bog covers between 100,000 and 200,000 square kilometres (40,000 to 80,000 sq miles), with the peat layer reaching up to 7m (23) beneath the ground. It holds billions of tonnes of partially decayed vegetation.