Non-calcareous quaking mire

Very wet mires with poor fen vegetation. Quaking mires include mires formed by terrestrialization of water bodies which involves formation of floating rafts of peat, typically proceeding from marginal areas towards basin centre, where primary open water pools can remain. Also included in this type are mires without neighbouring water bodies layer but similarly high water saturation leading to quaking conditions occurring in high water throughput percolation mires. The mire basin is always fed by minerotrophic ground water from the catchment area. There is no regular surface patterning connected to water flow. Water quality varies from acidic to moderately acidic. Vegetation is minerotrophic poor fen vegetation including intermediate fen communities (pH below 7). The lack of raised peat domes separate quaking mires from D1.1 Raised bogs, the lack of string patterning and slope from D3.2 Aapa mires and the lack of true rich fen indicator species (Scorpidium spp. et al.) from D4.1c Calcareous quaking mires.

Non-calcareous quaking mires are characterized by poor fen to medium rich vegetation including Calla palustris, Carex limosa, Carex rostrata, Carex aquatilis, Eriophorum angustifolium, Equisetum fluviatile, Menyanthes trifoliata, Potentilla palustris, Rhynchospora alba, Scheuchzeria palustris and Utricularia intermedia among vascular plants. Sphagnum cuspidatum, Sphagnum platyphyllum, Sphagnum subsecundum, Sphagnum majus and Warnstofia spp. are characteristic among bryophytes. Hepatics are sometimes abundant, most typically Cladopodiella fluitans. Floating peat rafts may also form surfaces elevated from water level with for example Sphagnum fallax and Eriophorum vaginatum or Molinia caerulea. When the floating peat raft becomes thick enough nearly ombrotrophic hummock like surfaces with e.g. Sphagnum magellanicum, Andromeda polifolia and Vaccinium oxycoccos can occurr. Even in such cases deep-rooted minerotrophic vascular plants like Menyanthes trifoliata can be found. Excluded are stands of vegetation fringing water bodies (see C3.2) unless the vegetation raft is sufficiently extensive to count as a habitat in its own right.

Indicators of good quality:

• water table always at surface; it can always be readily observed

• packing density of peat is low, walk-on leads to characteristic yielding (quaking)

• drainage ditches may affect quaking mires by lowering water level either permanently or increasing fluctuation and, thus, the likeliness of temporal drought or flooding with polluted water

• deteriorating quality is indicated by loss of wet mire area associated species e.g. among birds, increase of trees and bushes, and of hummock vegetation

Synthesis of Red List assessment

Confidence in the assessment

Pressures and threats