Carr (landform)

A carr is a type of waterlogged wooded terrain that typically marks a stage of succession between an original reedy marsh and the likely eventual growth of forest in a sub-maritime climate. Carrs are wetlands dominated by shrubs rather than trees, and the carr is one step in a hydrosere, the progression of vegetation that begins on terrain submerged by fresh water along a river or lake margin. The sequence starts with reed marsh. As the reeds decay the soil surface rises above the water and creates fens in which sedge can grow. Riparian trees and bushes then appear, producing a carr, in effect a wooded fen on waterlogged ground. At this stage the soil is not too acidic or too short of minerals, which makes a habitat for endemic and other wildlife. Characteristic water-tolerant trees include alder and willow. The word comes from the Old Norse kjarr, meaning brushwood, from a phrase for a marsh overgrown with brushwood.