Raised bog hummocks, ridges and lawns

Description (English)

Vegetation of the higher parts of the plateau of Palaearctic bogs and of its drier, marginal slope. Intact, typical, raised bogs of northern, lowland and low montane central and eastern Europe display an alternance of well-marked sphagnum hummocks, colonized or not, especially in their drier upper part, by small shrubs, lower, wetter, flat lawns and wet hollows or schlenken. Sphagnum hummocks with no, or few, shrubs are listed in unit Q11111, sphagnum hummocks, or parts of them, colonized by shrubs in unit Q11113, lawns in unit Q11112. In bogs under strong oceanic influence, in high-altitude bogs, in bogs subjected to minerotrophic influences or anthropogenic degradation, a sparse cover of shrubs or tussock-forming graminoids may become ubiquitous and the distinction between hummock and lawn, or even between hummock, lawn and hollow, blurred, in bogs that are often somewhat intermediate towards blanket bogs. Such communities are listed in units Q11114 to Q11116, as well as in Q1114 and in Q1121; in some of them sphagna may be scarce or replaced by bryopsid mosses. Well-defined sphagnum hummocks of unit Q11111 may nevertheless develop in conjunction with them. The dominance role is played by deergrass, Scirpus cespitosus, in montane central European bogs, or parts of bogs listed in unit Q11114. In Atlantic bogs listed in unit Q11115 it is played by Erica tetralix. Somewhat degraded bogs, in particular, bogs affected by anthropozoogenic influences in Atlantic climates, may be overwhelmingly dominated by Eriophorum vaginatum, usually with complete blurring of the structure. They are listed in unit Q11116. More severely degraded bogs, invaded by Molinia caerulea, are listed in unit Q1121. The highly distinctive shrub and sphagnum or shrub and moss hummocks bog expanses of the montane, rapidly dessicating, bogs of the boreal and subarctic zones are listed in unit Q1114 Sphagnum hummocks forming in acidic fens (units D2.2 in EUNIS 2012 now split in Q22, Q23, Q24), transition mires (unit Q25) or, sometimes, rich fens (unit D4.1 of EUNIS 2012 now split in Q41, Q42, Q43, Q44), are also indicated by codes of units Q11111 or Q11113.

Source: EUNIS habitat classification