peat An organic soil or deposit; in Britain, a soil with an organic soil horizon at least 40 cm thick. Peat formation occurs when decomposition is slow owing to anaerobic conditions associated with waterlogging. Decomposition of cellulose and hemicellulose is particularly slow for Sphagnum plants, which are characteristic of such sites, and hence among the principal peatforming plants. Fen and bog peats differ considerably. In fen peats the presence of calcium in the groundwater neutralizes acidity, often leading to the disappearance of plant structure, giving a black, structureless peat. Bog peats, formed in much more acidic waters, vary according to the main plants involved. Species identification of constituents (including animals as well as plants) remains possible after long periods. Recent bog-moss (Sphagnum) peat is light in colour, with the structure of the mosses perfectly preserved.

peat An organic soil or deposit; in Britain, a soil with an O horizon at least 40 cm thick. Peat formation occurs when decomposition is slow owing to anaerobic conditions associated with waterlogging. Decomposition of cellulose and hemicellulose is particularly slow for Sphagnum plants, which are characteristic of such sites, and hence among the principal peat-forming plants. Fen and bog peats differ considerably. In fen peats the presence of calcium in the groundwater neutralizes acidity, often leading to the disappearance of plant structure, giving a black, structureless peat. Bog peats, formed in much more acidic waters, vary according to the main plants involved. Species identification of constituents (including those of animals as well as of plants) remains possible after long periods. Recent bog-moss (Sphagnum) peat is light in colour, with the structure of the mosses perfectly preserved.

peat An organic soil or deposit; in Britain, a soil with an O horizon at least 40 cm thick. Peat formation occurs when decomposition is slow owing to anaerobic conditions associated with waterlogging. Decomposition of cellulose and hemicellulose is particularly slow for Sphagnum plants, which are characteristic of such sites, and hence are among the principal peat-forming plants. Fen and bog peats differ considerably. In fen peats the presence of calcium in the ground water neutralizes acidity, often leading to the disappearance of plant structure, giving a black, structureless peat. Bog peats, formed in much more acidic waters, vary according to the main plants involved. Species identification of constituents (including those of animals as well as of plants) remains possible after long periods. Recent bog-moss (Sphagnum) peat is light in colour, with the structure of the mosses perfectly preserved.

peat / pēt/ • n. a brown, soil-like material characteristic of boggy, acid ground, consisting of partly decomposed vegetable matter. It is widely cut and dried for use in gardening and as fuel: cuttings are rooted in a homemade mixture of equal parts peat and sand | [as adj.] most of Lewis is acid peat bog. DERIVATIVES: peat·y adj.

peat A mass of dark-brown or black fibrous plant debris produced by the partial disintegration of vegetation in wet places (see hydrosere). It may accumulate in depressions. When subjected to burial and hence pressure and heat it may be converted to coal. Peat is used to improve soil and as a fuel, especially in Ireland and Sweden.