Barnsley Biodiversity Trust: Barnsley Biodiversity Action Plan. Last Updated January 2016

Wetlands - fen, marsh and swamp. In floodplains and around the margins of ponds, canals and ditches, as well as slow-moving sections of streams and rivers, there are often wetland areas with rushes, sedges and reed grasses on a wet and sometimes peaty soil.

These offer some of the richest areas for dragon and damselflies and other invertebrates, amphibians, birds such as the nationally rare Bittern, and mammals such as Water Vole and Harvest Mouse.

Wetland habitats - fen, marsh and swamps

Wetlands that are normally flooded throughout the year give rise to swamp with tall reed grasses such as common reed, reedmace and reed canary grass, emerging from the water.

In areas not always flooded, mire or fen can be found on permanently wet peat or peaty soil and marshy grassland on less water-logged, but still damp soils. Scrub encroachment can result in wet woodland.

Although all forms of wetland habitat support wildlife, the most significant is reedbed - swamp dominated by common reed Phragmites australis - with its distinctive range of breeding birds including the nationally rare bittern.


There are a number of reedbeds in Barnsley in river valley situations, in former colliery lagoons, or planted for water treatment with the largest reedbed in the area at RSPB Old Moor and Bolton Ings (>12 ha).

There are small areas of remnant lowland fen with underlying peat at Gypsy Marsh, Adwick Washlands and Carlton Marsh.

Fen vegetation can also be found on the upland moors, falling within the Upland flushes, fens and swamps priority habitat.

Priority habitat

Fen, Marsh and Swamp is a broad habitat category under the UK BAP.

Reedbed, lowland fen, and upland flushes, fens and swamps are each identified as UK priority habitat within the broad habitat category.

These are within the mire (fen) and swamp categories of phase 1 habitat surveys and mire, and swamp & tall herb-fen NVC plant communities.

All these habitats have potential value for wildlife.

Three local priority habitats have been identified:


Lowland fen

Upland flushes, fens and swamps

The best examples of these local priority habitat are sites that support species of high conservation importance, such as bittern; support good populations or assemblages of key species such as water vole, amphibians, dragon or damselflies; or provide a rich site for wetland plants or invertebrates.

It should be noted however that some types of wetland vegetation can be invasive and care should be taken to prevent other valuable habitat being lost.

Factors causing loss or decline in quality of wetland habitats

Good practice in management

We welcome your comments
Your email address will not be public.

Further information is provided on pages on the wetland priority habitats via the links below: