As rainfall flows through or over the land it picks up nutrients. If this water then settles or collects it can form a rich wetland known as a fen. The type of water flow and rock beneath can create either acidic of calcareous fens either high or low in nutrients.
Fens can contain a staggering diversity of wildlife. The best fens can contain over 500 species of plants, nearly a third of all the plants native to the UK. The standing water and plant diversity attracts large numbers of insects such as water beetles and dragonflies. The cover and shelter provided by tall grasses and scrub draws in a number of bird species.
Many fens have disappeared as they have been drained to turn the land over to agriculture. In other situations, trees have taken over and formed wet woodlands and swamps. As an area where water collects, polution can accumulate in the fen changing the structure of the vegetation.
Use the navigation bar on the left to explore other wetland habitats or go back to go back to Biodiversity in the National Park.
Thursdy 27 March 2008
News updatefind out what's new in the Park
Popular waterfall reopensThe path behind Sgywd yr Eira has re-opened