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
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.