Mire

A mire is a type of wetland characterized by saturated soils and persistent waterlogging. The term covers several forms, including bogs, fens, swamps, and marshes, and in common usage often refers to peat-forming wetlands. The word derives from Old English myre, meaning bog or swamp.

Mires form where water accumulates at or near the surface and decomposition is slowed by anaerobic conditions. In many mires, especially bogs, dead plant material accumulates as peat. Bogs are typically ombrotrophic, receiving nutrients from precipitation and tending to be acidic and nutrient-poor; fens receive groundwater or surface water and are less acidic and more nutrient-rich. Swamps and marshes are characterized by standing water with substantial vegetation, whether herbaceous or woody.

Ecologically, mires sequester carbon, support specialized flora such as Sphagnum mosses and ericaceous shrubs, and provide habitat for birds, amphibians, and invertebrates. They influence hydrology by buffering floods, recharging aquifers, and helping maintain water quality.

Threats include drainage for agriculture, peat extraction for fuel or horticulture, development, and climate change. Restoration projects aim to rewet degraded sites, restore natural hydrology, and reestablish peatland vegetation; full recovery often requires many decades.

Historically, peat has been used as fuel and a growing medium. Today, peatland conservation and restoration are priorities in many regions, particularly in boreal and temperate zones of the Northern Hemisphere.