The archaeological record of 10,000 years of human habitation on Dartmoor (England) is under serious threat from bracken invasion. Spreading at a rate of more than 2 per cent a year and overpowering heather and unimproved grazing grounds, this coarse plant has root systems powerful enough to eat into the granite bedrock of the heathland and can have a devastating effect on underground structures and artefacts.
     The rapid spread is attributed to changes in farming practices on the high moor. Grants have encouraged the reduction of sheep flocks and cattle herds. Economies have pushed farmers towards more sheltered grazing in winter and early spring. The closure of the tin industry and a ban on live exports to France has reduced the value of the famous Dartmoor ponies to the extent that owners can no longer afford to keep them. The population of these grazing animals has been reduced from 30,000 to 3,000. The traditional use of bracken for bedding and fodder has been discontinued since the discovery of carcinogens in summer spores. Without livestock to trample it or people to pick it the bracken invasion is likely to continue. And as the bracken spreads, tourists and the remaining livestock are being forced onto fewer paths, causing more erosion.
     The Dartmoor Preservation Association is organising ‘stomping’ and strimming parties to try and eliminate the problem, but the Department for Environment, Food and Rural Affairs is urging more drastic action. The Environmentally Sensitive Area scheme offers grants for the control of bracken with tractors or chemicals. But Andy Guy, regional development officer for DEFRA, says that few farmers are taking up the scheme because it is felt that insufficient funding is on offer and because many sites are too remote. Mr. Guy is worried that parts of the moors are already beyond saving.
     This part of Devon has been home to dinosaurs and giant redwoods, has seen earthquakes, volcanic activity and ice ages, and has been flooded by the sea at least twice.

Source: Observer (7 September 2003)