Understanding the origins of 'blanket bog' on our Uplands.
Understanding the origins of 'blanket bog' on our Uplands.
Blanket bog represents around 6% of the area of the UK. When explaining how these lonely expanses of land can be explained a popular view is that early human populations cleared forest as they settled into a more agrarian way of life.
That explanation has again been challenged recently by research that suggests that climate rather than land-use history might explain blanket bog distribution. This is outlined in an academic paper entitled "Climate-driven expansion of blanket bogs in Britain during the Holocene" by Angela Gallego-Sala (and collaborators, et al). This suggests that it is possible to use bioclimatic modelling to show how climate conditions around eight to ten thousand years ago were right for the formation of the blanket bogs.
This modelling study identified when summer temperatures were not too high for Sphagnum growth and there was enough moisture throughout the year to sustain peat growth on sloping ground.
A landslip following heavy rains in Northumbria shows two metres of peat build on sloping rock.
What Angela Gallego-Sala does is use modelling to show that most likely, around 6000 years ago, and perhaps from as much as 4000 years earlier, blanket bog developed across much of Scotland, the North of England, Wales and parts of southern England.
There is certainly evidence that some upland areas were made more open by settlement and stock grazing. Equally there is an academic view (and archaeological evidence) that many farming communities, such as in Scotland, only settled once the landscape was already blanket bog. What Angela Gallego-Sala shows is that our landscape and environment is subject to far more variables than a single explanation affords.
This is an interesting addition to the range of evidence and thinking around the nature of our upland landscapes. Our knowledge of the upland environment is always enhanced by whenever we broaden our understanding of the how, why and when the foundations of our landscape were laid.
Read: "Climate-driven expansion of blanket bogs in Britain during the Holocene" - PDF
http://centaur.reading.ac.uk/48736/1/197_Gallego-Sala%20et%20al.%2C%202015_cpd-11-4811-2015.pdf
Abstract and download link: