Poor fen
Encyclopedia
A poor fen is a natural wetland
habitat, consisting of dense low growth of small sedge
s and other plants. It develops on wet ground where the water is fairly acidic and has very few plant nutrients
.
Poor fen is intermediate between the taller vegetation of fen
, which occurs where the water is much less acidic, and the short, mossy vegetation of bog
, which is even more acidic.
s where much of the water is ombrotrophic
(derived directly from rainfall). It sometimes forms a floating mat over water or very wet peat, making a mobile surface known as quaking bog.
Poor fen is usually grazed
by wild animals or livestock
, which prevent ecological succession
into wet woodland
.
In north-western Europe
, characteristic plant species of poor fen communities include common sedge (Carex nigra
), carnation sedge (Carex panicea), star sedge (Carex echinata
), white beak-sedge (Rhynchospora alba
) and many other small sedges
, as well as other plants such as jointed rush (Juncus articulatus
), marsh cinquefoil (Potentilla palustris
), bog-bean (Menyanthes trifoliata), bog pimpernel (Anagallis tenella
), lesser skullcap (Scutellaria minor) and marsh valerian (Valeriana dioica). Sphagnum
mosses also occur, but are not dominant as they would be in bog vegetation. There may also be some grass
es, but these are usually inconspicuous amongst the sedges and rushes.
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
habitat, consisting of dense low growth of small sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
s and other plants. It develops on wet ground where the water is fairly acidic and has very few plant nutrients
Plant nutrition
'Plant Nutrition is the study of the chemical elements that are necessary for growth. In 1972, E. Epstein defined 2 criteria for an element to be essential for plant growth:# in its absence the plant is unable to complete a normal life cycle or...
.
Poor fen is intermediate between the taller vegetation of fen
Fen
A fen is a type of wetland fed by mineral-rich surface water or groundwater. Fens are characterised by their water chemistry, which is neutral or alkaline, with relatively high dissolved mineral levels but few other plant nutrients...
, which occurs where the water is much less acidic, and the short, mossy vegetation of bog
Bog
A bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
, which is even more acidic.
Ecology
Poor fen is found where the ground is permanently wet with nutrient-poor water which is somewhat acidic. For example it occurs as the vegetation of flushes (marshy springs on slopes), in places where neutral water enters more acidic bogs, in wet acidic grassland, and sometimes in the flatter parts of flood-meadowFlood-meadow
A flood-meadow is an area of grassland or pasture beside a river, subject to seasonal flooding. Flood-meadows are distinct from water-meadows in that the latter are artificially created and maintained, with flooding controlled on a seasonal and even daily basis.- Examples :* Angel & Greyhound...
s where much of the water is ombrotrophic
Ombrotrophic
Ombrotrophic refers to soil or vegetation which receive all of their water and nutrients from precipitation, rather than from streams or springs. Such environments are hydrologically isolated from the surrounding landscape, and since rain is acidic and very low in nutrients, they are home to...
(derived directly from rainfall). It sometimes forms a floating mat over water or very wet peat, making a mobile surface known as quaking bog.
Poor fen is usually grazed
Grazing
Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...
by wild animals or livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...
, which prevent ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...
into wet woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
.
Vegetation
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, characteristic plant species of poor fen communities include common sedge (Carex nigra
Carex nigra
Carex nigra Reichard is a perennial species of plants in the family Cyperaceae native to wetlands of Europe, western Asia, NW Africa and E North America. The eastern limit of its range reaches central Siberia, Turkey and probably Caucasus....
), carnation sedge (Carex panicea), star sedge (Carex echinata
Carex echinata
Carex echinata is a species of sedge known by the common names star sedge and little prickly sedge.-Distribution:This plant is native to North and Central America and parts of Eurasia. Carex echinata is a plant of wet forests, marshes, and mountain meadows of moderate elevation...
), white beak-sedge (Rhynchospora alba
Rhynchospora alba
Rhynchospora alba, the white beak-sedge, is a plant in the sedge family, Cyperaceae. It is a tufted herbaceous perennial plant found in fairly acidic wetlands which have few plant nutrients....
) and many other small sedges
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
, as well as other plants such as jointed rush (Juncus articulatus
Juncus articulatus
Juncus articulatus is a species of rush known by the common name Jointleaf Rush, and more ambiguously as "Jointed Rush" which can also refer to J. kraussii from Australia . It is native to Eurasia and much of Canada and the United States. It grows in moist areas, such as wet sand, and thrives in...
), marsh cinquefoil (Potentilla palustris
Potentilla palustris
Comarum palustre , known by the common names Purple Marshlocks, Swamp Cinquefoil and Marsh Cinquefoil, is a common waterside shrub. It has a Circumboreal distribution, occurring throughout North America, Europe, and Asia, particularly the northern regions...
), bog-bean (Menyanthes trifoliata), bog pimpernel (Anagallis tenella
Anagallis tenella
Anagallis tenella known in Britain as the Bog Pimpernel, is a low growing, perennial plant found in a variety of damp habitats from calcareous dune slacks to boggy and peaty heaths in Eurasia but absent from North America...
), lesser skullcap (Scutellaria minor) and marsh valerian (Valeriana dioica). Sphagnum
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...
mosses also occur, but are not dominant as they would be in bog vegetation. There may also be some grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
es, but these are usually inconspicuous amongst the sedges and rushes.
See also
- BogBogA bog, quagmire or mire is a wetland that accumulates acidic peat, a deposit of dead plant material—often mosses or, in Arctic climates, lichens....
- FenFenA fen is a type of wetland fed by mineral-rich surface water or groundwater. Fens are characterised by their water chemistry, which is neutral or alkaline, with relatively high dissolved mineral levels but few other plant nutrients...
- MarshMarshIn geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
- British National Vegetation ClassificationBritish National Vegetation ClassificationThe British National Vegetation Classification or NVC is a system of classifying natural habitat types in Great Britain according to the vegetation they contain....
- Mires in the British National Vegetation Classification systemMires in the British National Vegetation Classification systemThis article gives an overview of the mire communities in the British National Vegetation Classification system.-Introduction:The mire communities of the NVC were described in Volume 2 of British Plant Communities, first published in 1991, along with the heath communities.In total, 38 mire...
(see especially M5 to M14, and M31 to M38)