Multamaiset

Multamaiset is a term used in Finnish soil science to categorize organic soils that are predominantly composed of decomposed plant material, forming thick humic horizons often associated with peatlands. In practice, multamaiset soils develop in waterlogged environments where decomposition is slowed, allowing plant residues to accumulate as peat.

These soils are characterized by high organic matter content, low bulk density, and pronounced water saturation. They typically exhibit acidic pH, low nutrient availability, and a spongy, fibrous texture due to the peat matrix. The upper horizons may be dominated by humified organic matter, while underlying layers can include mineral material mixed with peat.

Multamaiset soils are common in boreal and subarctic regions, especially in mires such as bogs and fens, where hydrology maintains saturated conditions. They play a crucial role as carbon sinks, storing large amounts of atmospheric carbon in peat deposits.

Ecologically, multamaiset areas support specialized vegetation, including Sphagnum mosses, sedges, and ericaceous shrubs, and they harbor unique invertebrate and plant assemblages. They are highly sensitive to drainage, peat extraction, and climate change, which can alter hydrology and accelerate peat decomposition.

Management of multamaiset landscapes emphasizes wetlands preservation, restoration of natural water regimes, and sustainable peat use. Conservation aims include maintaining carbon storage, biodiversity, and hydrological functions, while reclamation projects often seek to rewet degraded areas.

See also: peatland, mire, organic soil, humus.