Ecological Investigations of the Scottish Lichen Flora

Scotland’s lichen flora is one of its greatest contributions to biodiversity. High topographic, climatic and geological diversity give rise to a wide range of habitats from arctic-alpine tundra to Atlantic woodland all coexisting within a small area. This wide array of habitats supports over 1500 species of lichens (37% of the European total) in only 0.75% of Europe’s surface area.

Knowledge of the Scottish lichen flora, its functioning and importance is still very much evolving, with taxonomic work being undertaken by staff at the Royal Botanic Gardens Edinburgh. The projects described here (carried out in collaboration between the Macaulay Institute and RBGE) focus on improving knowledge of lichen ecology, particularly in key habitats which are well represented in Scotland or which are thought to be potentially under threat e.g. from climate change, pollution or changes in land use. Taxonomic training is also an important part of these studies, helping to ensure that knowledge of Scotland’s lichen flora is passed on to a new generation of lichenologists.

Our work mainly focuses on what controls the distribution and abundance of montane lichens and how might this change in changing climate?

The montane (alpine) zone is one area where lichens make a particularly important contribution to biodiversity. Over 700 species of lichen have been recorded above the tree-line in Britain with around 287 being montane specialists. Montane lichens are also the second largest group on the British Lichen Red Data List and many species are protected under Schedule 8 of the Wildlife and Countryside Act or are included in the UK Biodiversity Action Plan. Climate change is considered a serious threat to the British montane flora as many species are already restricted to the highest summits and plateaux and so have no scope for upward migration. In addition, lichens are generally very slow growing and may have limited powers of dispersal. Air pollution and deposition of pollutants in rainfall is also a potentially serious problem in mountain areas. Many lichen species are very sensitive to pollutant exposure as they have evolved to be very efficient at capturing their nutrient requirements from air and rainfall which would normally contain very low concentrations of important elements such as nitrogen.

Our work covers

• Boulder fields
• Montane heathland and
• Modelling and monitoring