The remains of growing bog-mosses have accumulated over millennia, as they only decompose partially due to the saturated, oxygen-free conditions of the peat soil. Across a wide area the peat is now a metre deep and this volume of organic soil traps a great deal of carbon. As the peat accumulates more carbon is stored – a carbon `sink`.
A carpet of moss
Such wet, peat soils are unsuited for the growth of many plant species and the vegetation found is quite specialist. Most important of all is the carpet of bog-mosses ('Sphagnum' species) which continue to absorb water like a huge sponge and keep the blanket bog continually moist.
Growing through this moss layer are species such as cotton-grasses, crowberry, cowberry, cross-leaved heath, deer-sedge and real specialists like bog rosemary and sundews. Both round-leaved and oblong-leaved sundew can be found and both rely on catching small insects on their sticky hairs to supplement the poor nutrient supply from the peat.
A home for wildlife
As well as specialist plants the blanket bog is also home to many well-adapted invertebrates, the most prominent of which are the emperor and fox moths, both of which fly during the day. Meadow pipits are frequent here and can be seen and heard doing their `parachute` display flights in spring.
Blanket bog is not just a fantastic wildlife habitat but is also incredibly important in other ways. The peat soils contain vast amounts of stored carbon and, whilst there is an active layer of bog-moss growth, the carbon store continues to increase. Bog-mosses can retain many times their own weight of water and as a consequence blanket bogs can soak up rainfall, slow the run-off and help alleviate possible flooding.
Other great places to see this fragile habitat
As well as Whiteoak Moss, you can see blanket bogs on the fells above Watendlath in Borrowdale and on Kinniside Common south of Ennerdale. When you walk across this habitat you can avoid damaging it by following these guidelines:
Stick to paths to protect the plant-life
If you see exposed peat, avoid walking across it if you can