A carr is a type of waterlogged wooded terrain that, typically, represents a succession stage between the original reedy marsh and the likely eventual formation of forest in a sub[clarification needed]-maritime climate.
[2] The carr is one stage in a hydrosere: the progression of vegetation beginning from a terrain submerged by fresh water along a river or lake margin.
As the reeds decay, the soil surface eventually rises above the water, creating fens that allow vegetation such as sedge to grow.
As this progression continues, riparian trees and bushes appear and a carr landscape is created – in effect a wooded fen in a waterlogged terrain.
At this stage, overall, unlike the overwhelming acidity of decaying reeds, the pH is not too acidic and the soil is not too deficient in minerals, making a habitat for endemic and other wildlife.