What is ‘special’ about Cors y Farl SSSI?

Cors y Farl has 2 special features.

As well as the features listed above, Cors y Farl has other habitats that contribute to the special interest. These include a stream and small areas of peripheral scrub and broadleaf woodland.

This mixture of habitats is important for much of the wildlife including great fen sedge, black bog rush, blunt flowered rush and a variety of other sedges. Large stands of meadowsweet occur towards the periphery on the highest parts of the site. Cors y Farl is also noted for several rare and uncommon species of insects, while typical wetland birds such as grasshopper warbler or snipe nest or winter here.

Unless specified below, management of this site should aim to look after these habitats and species as well as the listed features of interest.

What do we want Cors y farl to look like?

At least 85% of the site should be wetland. In this we would expect to see a range of different plant communities characteristic of low fertility wetland soils – the main elements of this vegetation should include great fen sedge, mixtures of black bog rush and blunt flowered rush, and common reed. Water levels and quality should be maintained to support these communities. Patches of grey willow should remain and a few ash trees in the periphery but in total should not be permitted to exceed 15% of the wetland area.

What management is needed on Cors y farl SSSI and why?

Although Cors y Farl is an excellent place for wildlife it will only remain so if the necessary management continues. CCW’s aim is to work with you to ensure that this management is carried out.

What does this mean in practice?

There are many factors that could damage the special features at Cors y farl if they are not properly managed. These are the ones we regard as most important:

Water level and movement: Maintaining a high groundwater level is essential for the survival of wetland plants and animals. It is therefore important that no work is carried out which would lower water levels on the site – for example by widening, deepening or clearing ditches. Past ditching and drainage continues to remove water from the site and may need review, with the possibility of modification, in due course. However, some wetland plants and animals require very shallow surface water or moving groundwater, so deep or prolonged flooding can destroy these. Raising water levels should not be undertaken without careful assessment. Equally important is the need to maintain the current water supply to the site through springs, groundwater seepage, ditches and surface run off. Any actions that would reduce the amount of water entering Cors y Farl would be damaging to the site.

Water quality: Good water quality is essential for maintenance of the characteristic assemblage of wetland plants and animals at Cors y Farl. Nutrients such as nitrogen and phosphorous encourage the spread of strong growing plants such as float-grass and common reed which can out-compete the less common (and more desirable) species at Cors y farl. This in turn would have a negative effect upon the animals that depend on these plants. Measures to enhance soil fertility within the catchment of the site are therefore likely to prove harmful to the special interest features of Cors y Farl.

Grazing: Light grazing of wetlands removes excess plant material. The most appropriate grazers here are cattle or ponies as they can maintain open areas in wetland by browsing scrub and by light poaching of the ground. Animal dung also provides an important food resource for some invertebrates. There should be no supplementary feeding with silage as this increases soil nutrient levels. Hay may be fed in severe weather, mineral licks used to enable the animals to digest coarse material and small quantities of concentrates to keep livestock tame.


The site, along with neighbouring fens, may be used by wintering harriers. Occasional shooting for snipe is tolerated but should not be increased beyond current levels

Scrub and woodland control: Scrub (including willow) and woodland (including ash) provides nesting places for birds and shelter for other animals. However too much scrub and woodland can alter the special qualities of the wetland site, increasing evaporation of water and shading wetland species. Grazing alone may not be enough to prevent scrub and woodland expansion and it may sometimes be necessary to carry out scrub control manually.

Fire: Fire was regularly used in the past to clear the land, promote new growth and attract grazing animals. However uncontrolled fires can damage some plant and animal communities and its use should be very strictly limited on fen. Small, controlled fires in winter may be used to rejuvenate small patches of fen with excess leaf litter and to create more diversity of structure.


Our knowledge of wildlife is far from complete. It is possible that new features of value may appear and new management issues may arise in the future, whilst other issues may disappear. This statement is written with the best information we have now, but may have to change in the future as our understanding improves. Any information you can provide on the wildlife of your site, its management and its conservation would be much appreciated.

If you would like to discuss any aspect of your SSSI, or have any concerns about your SSSI, please contact your local CCW office.

Your local office is;

Cyngor Cefn Gwlad Cymru/Countryside Council for Wales

Llys y Bont,

Ffordd y Parc,

Parc Menai,


Gwynedd, LL57 4BN,

Telephone: 01248 672500

Fax: 01248 679259