The exceptional Scottish climate

Lying on the western seaboard of Europe, in the track of the Atlantic depressions, Scotland has a climate that is unique in Europe. It is described as extreme oceanic i.e. it is influenced by the surrounding seas. The diagram opposite shows how even the Scandinavian fjords, Brittany, Cornwall and Wales have lower oceanicity scores. High values indicate a combination of extreme humidity, abundant rainfall and number of rain days (days when rain falls), persistent cloudiness, cool summers and mild winters. The Gulf Stream helps to make the climate warmer with the result that along the west coast there are numerous sites, such as Inverewe Gardens, where palm trees flourish.

Woodland lichens which grow best in, or require, a mild, wet climate thrive here. Oak woods bordering the western sea lochs are 'dripping' with lichens that are rare in Europe as a whole.

A number of these lichens are endemic to Scotland which means they occur nowhere else in the world.

The unusual climate affects all lichen communities. The mountains in the west experience a lower snow cover than those elsewhere and their rocks are so continuously wet that lichen species normally restricted to damp rock are ubiquitous. The wet ground favours peat formation so some flat areas are covered with a community known as blanket bog. The sodden moorland that results has its own suite of very beautiful lichens which can be seen beside trackways or around the margins of disused peat cuttings. These include clumps of reindeer lichens, patches of pixie-cup and horn lichens (Cladonia species).