Fen

A fen is a type of wetland. It is usually fed by mineral-rich surface water or groundwater.Godwin K.S. et al 2002. Linking landscape properties to local hydrogeologic gradients and plant species occurrence in New York fens: a hydrogeologic setting (HGS) framework. Wetlands, 22, 722–37.  Fens have neutral or alkaline water, with dissolved minerals but few other plant nutrients. They are usually dominated by grasses and sedges, and typically have brown mosses like Scorpidium or Drepanocladus.Keddy P.A. 2010. Wetland ecology: principles and conservation. 2nd ed, Cambridge University Press.p8 

Fens may have a high diversity of other plant species, including carnivorous plants such as Pinguicula.ch9Wheeler B.D. and Giller K.E. 1982. Species richness of herbaceous fen vegetation in Broadland, Norfolk in relation to the quantity of above-ground plant material. Journal of Ecology, 70, 179–200. Fens may occur along large lakes and rivers where seasonal changes in water level keep soil wet, with few woody plants.Charlton D.L. & Hilts S. 1989. Quantitative evaluation of fen ecosystems on the Bruce Peninsula. In Ontario Wetlands: inertia or momentum? eds. M.J. Bardecki and N. Patterson, pp. 339–54. Proceedings of Conference, Ryerson Polytechnical Institute, Toronto, Oct 21–22, 1988. Toronto, ON: Federation of Ontario Naturalists. 

The distribution of individual species of fen plants is connected to water regimes and nutrient concentrations.Slack N.G; Vitt D.H. & Horton D.G. 1980. Vegetation gradients of minerotrophically rich fens in western Alberta. Canadian Journal of Botany. 58, 330–50.Schroder H.K. et al 2005. Rejecting the mean: estimating the response of fen plant species to environmental factors by non-linear quantile regression. Journal of Vegetation Science, 16, 373–82.

Fens have a characteristic set of plant species, which indicate environmental conditions. They are called "fen indicator species".Godwin K.S. et al 2002. Linking landscape properties to local hydrogeologic gradients and plant species occurrence in New York fens: a hydrogeologic setting (HGS) framework. Wetlands, 22, 722–37. Table 3.

Fens are distinguished from bogs. Bogs which are acidic, low in minerals, and usually dominated by sedges and shrubs, with abundant Sphagnum mosses.p8

Fens have been damaged in the past by land drainage, and also by peat cutting.Sheail J. & Wells T.C.E. 1983. The Fenlands of Huntingdonshire, England: a case study in catastrophic change. In Ecosystems of the World, vol. 4B Mires: Swamp, Bog, Fen and Moor – Regional Studies. ed. A.J.P. Gore, pp. 375–93. Amsterdam: Elsevier.  Some are now being carefully restored with modern management methods.ch13 The principal challenges are to restore natural water flow regimes, to keep the quality of water, and prevent invasion by woody plants.

 Related pages 
The Fens

 References 

Category:Wetlands