Sphagnum or ‘Bog-moss’ is an often overlooked or ignored member of the plant world, but as well as being of great economic importance, when looked at more closely, it is of great beauty due to its range of colours and textures.
No fewer than 24 different kinds of Sphagnum are found in Berwickshire, out of the national total of 35, and these are found mostly in raised bogs such as Drone Moss and Dogden Moss and the blanket peatlands covering the Lammermuir Hills.
Next time you stray into a Sphagnum bog try squeezing a handfull of the moss, to see the amount of water it holds - up to 15 times its dry weight. The leaves and stems of Sphagnum are miniature sponges filling up with water, retaining rainfall and preventing rapid run-off and flooding downstream.
As the older parts of Sphagnum plants decay they turn into peat, which since the last ice age has accumulated to considerable depths over our moors and constitutes a very important commercial resource, used in horticultural compost and as a fuel source for heating and power generation. Peatlands are very extensive in Scotland, northern Europe, Asia and America, and these have huge importance as a ‘carbon sink’, holding more carbon than all other plants put together, and almost as half as much as is held in atmospheric carbon dioxide. Loss of our big peatlands such as the ‘Flow Country’ in Scotland by drainage or other changes could contribute significantly to climate change.
Sphagnum, in common with most other mosses, hardly ever gets eaten by animals or insects due to having evolved protective defences in the form of special chemical compounds which make them taste very unpleasant. Even more remarkably, they never seems to be attacked by pests such as bacteria or fungi - in other words they have evolved highly effective and natural antibiotic properties. These medicinal properties seem to have been largely ignored, except in the case of using Sphagnum mosses as wound dressings for injured soldiers. Knowledge of its value for wound dressing goes back many centuries, for example after the battle of Flodden in 1513, highlanders reputedly knew how to use Sphagnum and grass to staunch their wounds.
However, not until World War I did this grow into a major industrial operation.
Southern Scotland, including Berwickshire, was surveyed for its Sphagnum mosses, led by Isaac Bayley Balfour of the Royal Botanic Garden, Edinburgh. A network of collectors developed quickly, leading to vast quantities being harvested in the countryside and dried in Edinburgh for shipment to the battlefields of France - up to one million Sphagnum dressings per month were sent from Britain by the end of the war. These dressings had a double benefit - the Sphagnum moss could absorb large volumes of fluid from wounds, and at the same time the antiseptic properties meant that wounds healed quickly, greatly reducing the number of amputations and deaths from infection. The filthy conditions made the trenches a hotbed of infections, and the effectiveness of these dressings was remarkable. It was found that some species of Sphagnum were better than others, and some of the enthusiastic collectors needed training in moss identification so that they did not collect the wrong kinds of moss!