Bog
Bog, an expanse of wet, spongy ground composed largely of partially decayed or decaying plants. Bogs are most common in northern parts of the world, including the northern United States and southern Canada. Large bogs cover much of Ireland. The word itself is Irish and means "soft." Bogs are generally not more than 25 feet (8 m) deep, but some go down twice that far.
Bogs form in ponds and wet areas where drainage is poor and where mosses, in particular sphagnum, are a principal type of vegetation. Sphagnum moss makes the water it grows in acidic, and the bacteria that normally hasten the decay of plant material cannot grow. Large deposits of partially decayed plant material slowly accumulate, eventually filling in a body of water or forming a high ridge. The lower layers of a bog often develop into peat.
A few kinds of plants, including cranberries and pitcher plants, readily grow on bogs, but most plants cannot tolerate the acidic water. Some bogs, known as muskegs, also support the growth of grasses. The grasses usually form dense tufts called tussocks. Tamarack and black spruce trees, as well as grasses, often grow in muskegs.
A bog will shake underfoot when walked upon. On especially soft bogs, called quaking bogs, there is a danger of sinking into the mire. Tradition says that at the battle of Solway Moss in northwest England, in 1542, a troop of cavalry galloped into a bog and sank to the bottom.
Many bogs are drained to make cropland. They require heavy lime treatment to overcome their acidity. Some crops, such as lettuce, celery, and potatoes, thrive in reclaimed bog soil.