Blanket bog is found on moorland areas where there is a good depth of peat causing waterlogged and acidic conditions. Look closely into one of these bogs and you will see that it comprises an amazing mixture of bog loving plants such as bog aspohodel, cranberry, crowberry, cotton grasses, and a thick layer of Spagnum mosses in addition to the more typical heather.
Some plants, like the round-leaved sundew have special adaptions to survive in this environment and gain nutrients by digesting trapped insects.
Please take care when walking in boggy areas and respect the fragility of this rare habitat.
On boggy ground as on the Chain sthere are plants with flowers which appear to resemble cotton wool - in fact, bog cotton-grass as it is called, is a good indicator that you are looking at one of Exmoor's bogs
Blanket bog is found on moorland areas where there is a good depth of peat causing the drainage to be impeded. Look closely into one of these bogs and you will see that it comprises an amazing mixture of bog loving plants such as bog aspohodel, sundew, crowberry, cotton grasses, and a thick layer of Spagnum mosses in addition to the more typical heather.
These bogs are not only interesting in their own right, but also help to hold a huge amount of water in the upper catchments of rivers such as the Lyn and the Exe which helps to reduce flash floods.
In an attempt to drain these wet areas, drainage ditches had been cut into the peat historically which has not only caused degradation of the bogs, but has also led to considerable soil and peat erosion leaving large scars on the moorland landscape.
Exmoor National Park Authority has been working with other organisations such as English Nature, the Environment Agency and Defra in a pilot project known as MIRE - moorland Improvement and Restoration on Exmoor. Work has been carried out on 2 sites owned by the National Park Authority at Blackpitts and Exe Head, both within the Exmoor Forest. Different techniques are being trialed such as using wooden dams built across the ditches and blocking them with bales of heather.
Through the project, the National Park Authority now has its own mini-baler which has been used to bale heather which has been cut on moorland sites where firebreaks are required or where cutting is being used as an alternative to burning. The round bales are then packed tightly into the open ditches reducing the speed of the flow of water through them and allowing sediment to deposit and vegetation to subsequently develop. The project is now working with other landowners through the Exmoor ESA Scheme using lessons learnt from the pilot to benefit other areas.
During the last 5000 years the moorlands of Exmoor have developed a covering of blanket bog which in places is over 2 metres thick. The UK has 20% of the blanket bog in the world and a duty to look after it. This blanket bog has been modified by man over time as he utilised it, particularly for fuel and grazing. Peat cutting, burning and drainage have left a lasting legacy causing drying out and degradation. If action is not taken now the peat will continue to oxidise and disappear from Exmoor's moorlands.
Various blocking methods are being used including peat bunds, wooden dams and heather bales. The blocks will be no higher than 1 m to avoid creating deep water pools. Shallow pools are best for the promotion of bog moss (Sphagnum) growth. Heather and purple moor grass (Molinia) bales will be used to fill the deeper pools behind the ditch blocks. This will create a safer environment for stock, walkers and horse riders.
|