Blanket Bogs

Thousands of years old, formed of peat, nutrient poor - these evocative and wild habitats nonetheless have a rich and unique wildlife. Blanket bog in the uplands of Wales contributes to Britain and Ireland’s estimated 10-15% share of this globally scarce habitat type. Since our climate may no longer support the formation of new blanket peat bogs, we need to ensure that we look after those we still have.

In the wake of woodland clearance, and possibly linked to climate change around 5000 – 6000 years ago, extensive blanket bogs began to form in the wetter north and west of Britain.

Made of peat – a material formed when conditions are too wet and cold for plant remains to decay in the normal way – blanket bogs are acidic because of the lack of nutrients in rainwater. The almost continuous flow of water in these heavy rainfall areas washes out soil nutrients and leaves behind peat that can be over five metres deep.

There are extensive areas of such bog in the Welsh uplands, draped as a blanket of peat over ridges, plateaux and gentle slopes. Heather and the fluffy, white-headed cotton grasses often dominate the vegetation, but you’ll also find crimson and bright-green bog mosses and the yellow-flowered bog asphodel sometimes appears in wetter hollows and water seeps. On one or two sites in Wales you might be lucky enough to see the cloudberry in its most southerly locality in Britain. The plant resembles a low-growing raspberry and produces orange-coloured fruit when it’s ripe.

On these wet, acid blanket bogs, some plants find nutrients, especially nitrogen, from alternative sources – the sundews and butterworts, for example, have evolved an ability to get some of their nutrients by capturing and digesting insects.

Plants are not the only wildlife that make our blanket bogs their home. Precious populations of breeding waders and birds of prey depend on blanket bog, and you’ll also find red grouse - and the scarcer black grouse - here and in the drier upland heathland habitats in Wales.

But these vivid and wild habitats need our protection. Drainage, burning, overgrazing and cutting peat for fuel or garden uses have all contributed to its loss and degradation. Today, climate change and atmospheric pollutants pose a threat to even the best remaining examples. Some existing blanket bogs are still developing, but as our present climate may no longer be conducive to new peat formation, except locally, most of the damage cannot be undone.