FRESHWATER GRAZING MARSH (the title used in the "Living with the sea" project)

Coastal and floodplain grazing marsh

Coastal and floodplain grazing marsh is defined in the biodiversity action as "periodically inundated pasture, or meadow with ditches which maintain the water levels, containing standing brackish or fresh water. The ditches are especially rich in plants and invertebrates. Almost all areas are grazed and some are cut for hay or silage. Sites may contain seasonal water-filled hollows and permanent ponds with emergent swamp communities, but not extensive areas of tall fen species like reeds; although they may abut with fen and reed swamp communities." The definition used for the biodiversity action plan encompasses both coastal grazing marsh and coastal wet grassland.

[Comment - Differing perceptions as to what constitutes lowland wet grassland lead to anomalies in survey records. Because of this, information on the location and scale of coastal grazing marsh is fragmented and often subsumed within surveys of lowland wet grassland. The general term 'lowland wet grassland' can be applied to virtually all river valley grasslands and coastal marshes (Ward 1994). A similar definition was used for English Nature's survey namely "Lowland wet grasslands, including grazing marshes, normally occurring in lowland river valleys and behind sea defences.". Two principal features are important in defining the 'coastal' nature of the habitat: its origins and the degree of maritime influence. A general term of 'coastal wet grassland' is used to describe those grasslands which lie on the margins of tidal influence, but are subject to some, often limited maritime influence. More specifically 'coastal grazing marsh' is applied to sites where the coastal wet grassland is derived from marine (mostly salt marsh) sediments - these are the habitats, which are the focus for this section of the Guide.]

References

Ward, D. 1994. Management of lowland wet grassland for breeding waders. British Wildlife, 6/2., 89-98.