Foreword
Whilst Scotland's outstanding scenery is internationally renowned, the fact that its lichen communities are also of international importance is scarcely recognised. In commissioning this book from one of Britain's leading lichenologists, Scottish Natural Heritage is seeking to put that right.
Oliver Gilbert outlines their place in folklore and their role in the one-time world-famous Harris Tweed economy, but it is when he comes to describe some of the special places where lichens thrive that one senses just why these strange organisms make his spine tingle.
Those venturing onto the high ground of the Cairngorm plateau will find themselves in a lichen-dominated wilderness, which Oliver and his friend Brian Fox did much to describe. Some parts of the Celtic rain forest, their trees 'dripping' with lichens, are so remote they are still not fully explored for lichens, but you do not have to know the names of the lichens to know that you are somewhere special.
The importance of some habitats has only been recognised in recent years. It was not until the late 1970s that Brian Coppins of the Royal Botanic Garden Edinburgh realised that the twigs of Atlantic hazelwoods supported a distinctive lichen flora. One species discovered and named by him and Peter James of the Natural History Museum was the white-script lichen - probably endemic to Scotland.
Since Victorian times, lichens have been known to be good indicators of air pollution - rather like the canary down the coal mine. Back in those times, sulphur was the problem but this has largely been conquered with the clean air acts. Now the problems include nitrogen from both agriculture and vehicle exhausts, and global warming which may account for the apparent disappearance of certain species of snow-bed lichen in the Cairngorms. Global measures are required to conserve such lichen communities.
Lichens colour the landscape, especially where the air is 'pure as wine', but look closely at bark, wood and rock and you will see just how beautiful their intricate structures can be. Their fruit bodies, through which reproductive spores are produced, differ on the various species, some being like miniature jam tarts, others tiny volcanoes and, perhaps most fascinating of all - the 'writing' lichens - so called because of their resemblance to hieroglyphics.
Lichenology is a neglected science, but Oliver's account conveys the excitement of the chase.
Stephen Ward