Päivi Paasovaara

Kuusamon suokasvillisuus ja ojitustilanne

Paasovaara P. Kuusamon suokasvillisuus ja ojitustilanne.

Tiivistelmä

The percentage distribution of mire site types on 49 random sample plots (1/4 km2) was studied in 1989. The line transect method was used, the total mire transect line on the sample plots being 100,6 km. The eight most common mire site types include different pine bog types (hummock level bogs/pine mires) and fens. Both poor fens and rich fens are more common in Kuusamo than in the Pohjanmaa aapa mires (southern aapa mires), the former ones taking 29% and the latter ones 8% of all mires. The percentage of spruce mires (6% ) is no more than a half of their percentage in the Pohjanmaa aapa mires. 32% of the peatlands studied were under the influence of drainage, mainly with open ditch networks for forestry. 16% of those were classified as recently drained, 73% as transitional, 5% as drained peatland forests and 6% as being influenced by drainage in the vicinity. Open fens and thick peated mire types have been drained to a lesser extent than forested mires and sites with mire margin effect. However, as only few mire site types are suitable for forestry in northern Finland, the risk of unprofitable drainage is high. Mire site types considered unsuitable for forestry even in the more favourable conditions of southern Finland take about 35% of the drained mires. Keywords: Aapa mire area, draining for forestry, field survey, mire vegetation, Peräpohjola

Avainsanat
mire vegetation; Aapa mire area; draining for forestry; field survey; Peräpohjola

Vastaanotettu 31.10.2017 Julkaistu 1.1.1994

Katselukerrat 1219

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