Secrets of the Celtic Rainforest
Secrets of the Celtic Rainforest is a Plantlife Scotland project raising awareness of the international importance of these forests and unlocking the secrets of the unique species that dwell within them.
What are Celtic Rainforests?
The Celtic Rainforests of Scotland, also known as Atlantic woodlands, form part of the wider western Atlantic woodlands of the UK. They are a habitat known as ‘temperate rainforest’. Temperate rainforest is a rare habitat worldwide - rarer even than tropical rainforests! These mainly coastal forests have a special 'oceanic' climate, which is very wet and mild, due to landscape and warm ocean currents.
The combination of high rainfall and stable mild temperature makes the woodlands very humid which allows for the growth of some really special residents – the lichen, mosses and liverworts, fungi and ferns. It is these species that really make the Celtic Rainforests what they are. Not only do they help maintain the humidity in the forest but they also give the forests that mysterious and magical feel. We will hope to meet some of these forest residents along the way.
Where can I find these Rainforests?
Beyond Britain and Ireland coastal temperate rainforests, like our Celtic Rainforest, are found mainly in the redwood forests of western North America, the beech forests of western Chile, in south-east Australia, New Zealand, south-western Japan and Taiwan.
In Scotland they are mainly situated along the west coast.
What grows in the Celtic Rainforest?
The smaller plants of the Celtic Rainforest provide habitat and maintain the humidity levels necessary for the health of the forest. These special plants are called lichens and bryophytes (the mosses and liverworts) and some of them are very rare in the rest of Europe, but Scotland is a 'hotspot' for them.
- A lichen is unique because it is two organisms in one! A fungus and an alga/or cyanobacteria.
- Mosses and liverworts are ancient non-flowering plants, having been around for 400 million years. Mosses have small leaves that grow all round their stems, whereas liverworts have two ranks of leaves either side of their stem.
Let's meet some of the residents of Scotland's Celtic Rainforest:
Tree Lungwort (Lobaria pulmonaria)
A large ‘leafy’ lichen; it’s lobes look like the shape of human lungs. In fact in medieval times doctors used this lichen to treat lung disorders! It lives on tree trunks & branches. The west of Scotland is a particular ‘hotspot’ for this lichen due to the relative lack of atmospheric pollution here during the 19th Century Industrial Revolution. It is much more scarce in all other parts of Britain. When this lichen is dry it looks grey/bluish, but once it has rained, it changes to a lovely green!
Slender Mouse-tail Moss (Isothecium myosuroides)
Lives on tree trunks and boulders, forming dense mats. This moss has a tree-like growth form, unbranched near it’s base, becoming branched above. Its stems grow parallel to the ground or surface they are growing on. This moss provides a forest habitat in miniature for the micro-fauna of the woods.
Greater Whipwort (Bazzania trilobata)
Unlike other liverworts, the leaves of this species do not lie flat, but instead curl down from the stem to give it a more three-dimensional appearance. Its mainly found on earth banks, around tree bases, on boulders, rotting wood and occasionally tree trunks.
Are they threatened?
Unfortunately, yes. There are threats facing our native rainforests in Scotland:
- Rhododendron ponticum is invading the forests and shading out these special smaller plants and fungi
- The woodlands are becoming increasingly isolated and fragmented
- These woodlands benefit from the right amount of grazing - too little can lead to the woodland becoming shady and choked; but too much leads to more fragmentation and not enough regeneration of young trees.
Plantlife's Secrets of the Celtic Rainforest project raised awareness of these threats.