Alan Watson Featherstone, Founder of Trees for Life, writes about his experiences out in the Caledonian Forest, and about his work for the charity.


A lichen day in Glen Cannich

Lichen-covered rocks and cascading water of the Cannich River in Glen Cannich.

Lichen-covered rocks and cascading water of the Cannich River in Glen Cannich.

At the end of February I made a return visit to the area in Glen Cannich that I’d visited last December, which I wrote about in a blog back then. Because of the very short hours of daylight at that time of year, I hadn’t had the opportunity to fully explore that section of the Cannich River then. However, I’d seen enough to realise that there was a lot of interest to discover there, hence the reason for making another trip once the days were lengthening again.

Toothed crust fungus (Basidioradulum radula) on a dead birch branch.

Toothed crust fungus (Basidioradulum radula) on a dead birch branch.

Just before leaving for home at the end of that previous visit, I’d photographed what I thought initially might be a slime mould on a piece of dead rowan (Sorbus aucuparia) wood. Subsequently, thanks to a comment from someone who read my blog and confirmation from Liz Holden, a mycologist who helps with me fungal identifications, I discovered that it was in fact the toothed crust fungus (Basidioradulum radula), and not a slime mould at all.

Close up view of some of the 'teeth' of the toothed crust fungus (Basidioradulum radula).

Close up view of some of the ‘teeth’ of the toothed crust fungus (Basidioradulum radula).

Returning to the site at the end of February, I was surprised and delighted to immediately find some more of this fungus, on a dead birch branch this time, and only about 200 metres from where I’d seen it before.

Another view of the toothed crust fungus (Basidioradulum radula).

Another view of the toothed crust fungus (Basidioradulum radula).

 

 

 

 

 

 

 

This section of the toothed crust fungus (Basidioradulum radula) looked older, being more orange in colour.

This section of the toothed crust fungus (Basidioradulum radula) looked older, being more orange in colour.

There were several different patches of the fungus on a couple of broken sections of a birch branch, with some of them appearing quite fresh, while others, that were more orange in colour, were probably older.

Here several patches of the toothed crust fungus (Basidioradulum radula) can be seen amongst heather rags lichen (Hypogymnia physodes) on the birch branch,

Here several patches of the toothed crust fungus (Basidioradulum radula) can be seen amongst heather rags lichen (Hypogymnia physodes) on the birch branch.

 

 

 

 

 

 

 

Scots pines (Pinus sylvestris) on the small island in the Cannich River, beside some cascades.

Scots pines (Pinus sylvestris) on the small island in the Cannich River, beside some cascades.

Scots pines (Pinus sylvestris) on the small island in the Cannich River, beside some cascades.

Scots pines (Pinus sylvestris) on the small island in the Cannich River, beside some cascades.

 

 

 

 

 

 

 

Moving on a bit further, I came to the small island in the river that I’d explored during my previous visit. This time, though, I didn’t go on to the island itself, but explored the south bank of the river, opposite the island, where I had seen some interesting lichen formations on the rocks.

Cascades on a section of the Cannich River, separating the island from the south bank of the river.

Cascades on a section of the Cannich River, separating the island from the south bank of the river.

Closer view of the cascades on the Cannich River.

Closer view of the cascades on the Cannich River.

 

 

 

 

 

 

Wider-angle view of the cascades on the arm of the Cannich River that separate the island from the south bank.

Wider-angle view of the cascades on the arm of the Cannich River that separates the island from the south bank.

 

 

 

After stopping for a few minutes to photograph some cascades on the arm of the river that separates the island from the south bank, I went to have a close look at the lichen-covered bedrock just upstream from there.

Closer view of the lichen-covered bedrock and the circular water-filled pool on it.

Closer view of the lichen-covered bedrock and the circular water-filled pool on it.

Water-filled pool in lichen-covered bedrock, beside some cascades on the Cannich River.

Water-filled pool in lichen-covered bedrock, beside some cascades on the Cannich River.

Some sections of the bedrock were almost completely covered by round patches of crustose lichens, which contrasted with the colour of the rock itself. The circular shapes of these lichens were echoed by a depression in the bedrock, hollowed out by a stone rolled there by the current.

 

Another lichen-covered section of the bedrock, with the cascades on the river behind.

Another lichen-covered section of the bedrock, with the cascades on the river behind.

Here, the rapid, fluid motion of the water contrasts with the solidity of the rock, and very slow growth rate of the lichens on it.

Here, the rapid, fluid motion of the water contrasts with the solidity of the rock, and the very slow growth of the lichens.

The bedrock too had been sculpted by the flowing water, and looked almost of organic origin, such was its gently ridged and rounded shape. I was struck by the contrast between the rapid flow of the water and the almost glacial growth of the lichens – 0.1 mm per year for some lichens like these.

 

Closer view of the crottle or shield lichen (Parmelia saxatilis) growing over the quartz outcrop.

Closer view of the crottle or shield lichen (Parmelia saxatilis) growing over the quartz outcrop.

Nearby, I found a rock with a prominent band of quartz protruding from it, and partially covered with a common lichen species – crottle or shield lichen (Parmelia saxatilis).

Crottle or shield lichen (Parmelia saxatilis) growing over a quartz outcrop on a rock.

Crottle or shield lichen (Parmelia saxatilis) growing over a quartz outcrop on a rock.

 

 

 

 

 

 

 

Turquoise-coloured  lichen (Porpidia tuberculosa) and another lichen (Parmelia sp.) on a rock.

Turquoise-coloured lichen (Porpidia tuberculosa) and another lichen (Parmelia sp.) on a rock.

Because of the damp conditions, the lichens were all fully hydrated and many of them were brightly coloured as well. On another rock, a turquoise-coloured crustose lichen drew my attention.

Closer view of the turquoise-coloured lichen (Porpidia tuberculosa) and the Parmelia sp. lichen.

Closer view of the turquoise-coloured lichen (Porpidia tuberculosa) and the Parmelia sp. lichen.

 

 

 

 

 

 

 

Crustose lichen (Porpidia cinereoatra) with black apothecia on a rock beside the Cannich River.

Crustose lichen (Porpidia cinereoatra) with black apothecia on a rock beside the Cannich River.

I began to study the rocks beside the river carefully, as there were a lot of different crustose lichens growing on them. Crustose lichens are those which grow flush against their substrate – in this case the rocks. They secrete acids which break down the surface structure of the rock, liberating mineral compounds which are utilised by the lichen for its growth. When the lichen dies, its organic material breaks down and this is the beginning of the process of soil formation, with the minerals from the rocks becoming available for other organisms.

Lichens (Cladonia coccifera agg.) amongst liverworts and moss on a rock.

Lichens (Cladonia coccifera agg.) amongst liverworts and moss on a rock.

On another rock, where a little soil had accumulated, there were some fruticose lichens (Cladonia coccifera agg.) growing amongst some moss and liverworts. These are distinguished by the cup-shaped podetia, common to many lichens in the genus Cladonia, and the ring of small red discs on the rim of each of them. These are the apothecia – the structures that release the spores of the fungal partner in the symbiotic partnership between fungus and alga that forms each lichen species.

Here, the fruticose lichen on the left (Stereocaulon vesuvianum) is growing beside a 'fired egg' cluster of two crustose lichens - these cannot be identified to species from the photo alone.

Here, the fruticose lichen on the left (Stereocaulon vesuvianum) is growing beside a ‘fried egg’ cluster of two crustose lichens – these cannot be identified to species from the photo alone.

Cladonias are some of my favourite lichens, and although I often photograph them, this was the only example I saw during the entirety of this day in Glen Cannich. Instead, it was the crustose lichens that continued to draw my attention, and one of the rocks right beside the river I saw a white patch of crustose lichen with a smaller orange lichen growing partly within it. This combination gave all the appearance of looking just like a fried egg, spread thinly over the rock surface!

Another view of the pattern of crustose lichens (Fuscidea cyathoides and Porpidia tuberculosa) on a boulder.

Another view of the pattern of crustose lichens (Fuscidea cyathoides and Porpidia tuberculosa) on a boulder.

Pattern of crustose lichens (Fuscidea cyathoides and Porpidia tuberculosa) on a boulder in the forest.

Pattern of crustose lichens (Fuscidea cyathoides and Porpidia tuberculosa) on a boulder in the forest.

 

 

 

 

 

 

 

Another rock was almost entirely covered by an interlocking pattern of the turquoise lichen (Porpidia tuberculosa) I’d seen earlier and a brown lichen (Fuscidea cyathoides).

In this detailed photo of the boulder the bright green patches of map lichen (Rhizocarpon geographicum) are interspersed among the brown lichen (Fuscidea cyathoides).

In this detailed photo of the boulder the bright green patches of map lichen (Rhizocarpon geographicum) are interspersed among the brown lichen (Fuscidea cyathoides).

This boulder is completely covered in lichens, including Parmelia sp. at the top and then a mixture of the turquoise (Porpidia tuberculosa) and brown ones (Fuscidea cyathoides).

This boulder was completely covered in lichens, including Parmelia sp. at the top right and then a mixture of the turquoise (Porpidia tuberculosa) and brown ones (Fuscidea cyathoides) lower down.

 

 

 

 

 

 

 

The tranquility of the water in this pool, with a pine tree reflected in it, contrasts with the cascading water in the river behind.

The tranquility of the water in this pool, with a pine tree reflected in it, contrasts with the cascading water in the river behind.

 

 

 

Here the cudbear lichen (Ochrolechia tartarea), with its apothecia visible on the right, has grown over a bryophyte on the left - the structure of the moss is visible although it is covered by a layer of cudbear lichen material.

Here, cudbear lichen (Ochrolechia tartarea), with its apothecia visible on the right, has grown over a bryophyte on the left – the structure of the moss is clearly visible although it is covered by a layer of cudbear lichen material.

 

 

 

 

 

 

Another view of the  cudbear lichen (Ochrolechia tartarea), here growing next to the brown crustose lichen (Fuscidea cyathoides).

Another view of the cudbear lichen (Ochrolechia tartarea), here growing next to the brown crustose lichen (Fuscidea cyathoides).

 

This crustose lichen (Ophioparma ventosa) growing on a nearby boulder is noted for its blood red apothecia.

This crustose lichen is called blood spot lichen (Ophioparma ventosa) and is noted for its blood red apothecia.

 

 

 

 

 

 

 

Orange crustose lichen (Porpidia melinodes) and yellows crustose lichens (Lecidea sp.) on a rock.

Orange crustose lichens (Porpidia melinodes) and yellow crustose lichens (Lecidea sp.) on a rock.

 

 

Some of the rocks were very colourful indeed, with bright orange or yellow crustose lichens growing over them. One rock had a patch of the blood spot lichen (Ophioparma ventosa) which is readily distinguished by its blood red apothecia, and I’ve photographed that species previously in Glen Affric and on Dundreggan.

Another view of the white coral-crusted lichen (Pertusaria corallina).

Another view of the white coral-crusted lichen (Pertusaria corallina).

One large rock had a substantial patch of a white crustose lichen on it. This was the white coral-crusted lichen (Pertusaria corallina), and according to John Douglass, the lichenologist who helps me with lichen identifications, the clusters of white bumps on the lichen are galls.

This is the white coral-crusted lichen (Pertusaria corallina), and the raised white structures on it are apparently galls.

This is the white coral-crusted lichen (Pertusaria corallina), and the raised white structures on it are apparently galls.

 

 

 

 

 

Another view of the rocks covered in brightly-coloured lichens, including Porpidia melinodes and Porpidia tuberculosa.

Another view of the rocks covered in brightly-coloured lichens, including Porpidia melinodes and Porpidia tuberculosa.

 

This rock was covered in brightly-coloured crustose lichens, including Porpidia melinodes and Porpidia tuberculosa.

This rock was covered in brightly-coloured crustose lichens, including Porpidia melinodes and Porpidia tuberculosa.

 

 

 

 

 

 

 

It was nearing the end of the daylight hours, so I spent the last few minutes before I had to leave in an area where there were a lot of small boulders jumbled together, and all covered in bright orange and white crustose lichens.

This is another example of the combination of crustose lichens that look like a fried egg.

This is another example of the combination of crustose lichens that look like a fried egg.

This rock was almost entirely covered in the bright orange lichen (Porpidia melinodes).

This rock was almost entirely covered in the bright orange lichen (Porpidia melinodes).

 

 

 

 

 

 

More brightly-coloured lichens. The cluster of rocks in this area were all like this.

More brightly-coloured lichens. The cluster of rocks in this area were all like this.

 

 

View of some Scots pines (PInus sylvestris) and the area of lichen-covered boulders.

View of some Scots pines (Pinus sylvestris) and the area of lichen-covered boulders.

 

 

 

 

Another view of a group of the lichen-covered boulders.

Another view of a group of the lichen-covered boulders.

 

 

 

 

 

 

Slightly reluctantly, I packed up my equipment and headed back to my car, as the light was beginning to fade. I left with the overall impression of how colourful the lichens had been on the rocks there – quite a contrast to the dull, overcast grey day, but it was in fact those very conditions that enabled the lichens to be so vibrant.

Many thanks to John Douglass for his help in identifying some of the lichens in the photos on this blog.

 

 

 

Comments are closed.