Trees of Atlantic Rainforest

A range of tree species occur across Atlantic rainforest habitats, conveying different character, benefits and habitat diversity.

Hazel - Corylus avellana
The Atlantic hazelwoods of Scotland's west coast, particularly abundant in Argyll and Morvern, are a unique habitat home to endemic species such as Graphis alboscripta.

Oak - Quercus petraea and Quercus robur
Britain's two native oaks are perhaps the most characteristic species of temperate rainforest in Britain. The bark of mature oaks is sufficiently basic to support rich lobarion lichen communities.

Ash - Fraxinus excelsior
The basic bark of ash makes it a particularly important substrate for lichens. The widespread loss of ash due to dieback is having significant impacts for specialist epiphytic communities - non-native species such as sycamore (Acer psudoplatanus) may be able to reduce the harm caused by this decline.

Willows - Salix aurita, Salix cinerea, Salix caprea
The moderately basic bark of Salix caprea may contribute to epiphyte biodiversity in areas where ash has been lost.

Scots pine - Pinus sylvestris
In some areas, such as Beinn Eighe NNR, Scots pine form an unusual and ecologically significant coniferous rainforest habitat with downy birch, holly, rowan and juniper.

Rainforest Lichens

Lobaria virens

Lichens are fascinating composite organisms consisting of a mycobiont (fungus) and a photobiont (algae or cyanobacteria)... plus many other organisms including yeasts and bacteria.

Several lichens occurring in Scotland's temperate rainforest are globally threatened on the IUCN red list and/or are speceis for whih the British Isles have international responsibility for - e.g. Lobaria virens, Pectenia cyanoloma (pictured right).

Corticolous (epiphytic) lichen communities include:

Lobarion community: a community of basic bark with Lobaria, Sticta etc. A luxuriant community dominated by Lobaria pulmonaria is pictured right.

Parmelion community: community of acidic bark, with species including Sphaerophorous globosus (named for the swollen ball-shaped apothecia) pictured right.

Graphidion community: crustose lichens occurring on smooth barked species such as hazel and holly. The crustose script lichen Fissurina alboscripta is endemic to Scotland.

Pectenia cyanoloma

Lobaria pulmonaria

Sphaerophorous globosus

Rainforest Ferns

Polypodium vulgare, Trossachs

Filmy Ferns - Hymenophyllum spp.

These two inconspicuous ferns are strong rainforest indicators which grow amongst bryophyte cover on trees and rocks in oceanic areas. A useful ID feature is that the veins in Hymenophyllum wilsonii run all the way to the leaf tip, whereas they terminate significantly before in the rarer Hymenophyllum tunbrigense.

Polypody - Polypodium spp

This easily recognisable genus is not really a true "rainforest indicator" though it is more common in oceanic areas. There are three species of polypody native to Scotland. Although field characteristics can give a good indication, these are most reliably discerned by microscopic examination of the spores. The most common species in Atlantic rainforest in Scotland is Polypodium vulgare.

Hymenophyllum wilsonii, Loch Lomond

Rainforest Bryophytes

Bazzania trilobata

The most interesting temperate rainforest bryophytes tend tot to grow on the woodland floor, but are either epiphytes, or form mats or films on rocks.

Bazzania trilobata
A distinctive and useful rainforest indicator, the presence of Bazzania trilobata suggests good habitat for other, rarer Atlantic bryophytes.