Autumn in the Inverfarigaig rainforest

Inverfarigaig is a small village on the southeast side of Loch Ness, about halfway down the loch’s 23 mile length, which takes its name from the River Farigaig that discharges into the loch there. ‘Inver’ is derived from the Gaelic word ‘inhbir’,  meaning ‘the mouth of a river’ and the Farigaig flows from the Monadhliath Mountains, which lie between Loch Ness and the Strathspey valley to the east. Near its confluence with the loch, the river flows through a narrow gorge which provides both an important habitat and some degree of protection for a special area of woodland.

The narrow confines of the topography and the gorge’s west-facing aspect mean that it catches rainfall from the prevailing westerly winds, creating a local microcosm of temperate rainforest conditions. This, together with the base-rich soils in the ravines there and the more species-rich woodlands they sustain, has led to the Inverfarigaig woodland’s designation as part of the Ness Woods Special Area of Conservation – a site protected for its importance in a European context.

I first visited the Inverfarigaig woodland in the 1990s, and had been impressed by its special qualities and the lushness of the area, but had not returned since then. So it was that in early November I decided to rectify this long absence on my part, and went there for a day at the end of  autumn, hoping to still catch some of the life in the woodland, before it retreated into the dormancy of winter. It’s relatively rare for me to visit the east side of Loch Ness, as almost all of our work sites at Trees for Life are situated to the west of Loch Ness and Inverness.

Parking my car at the Forestry Commission car park, I walked down into the valley and was immediately impressed by the hazel trees (Corylus avellana) just changing into their autumn colours.

 

 

 

 

 

 

 

They had a mixture of green and yellow leaves on them, and were growing in amongst ash trees (Fraxinus excelsior) on the slopes. Inverfarigaig is noted for its more base-rich soils, and it is these which enable the ash trees to flourish here.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Down beside the burn, the hazels predominated, and their fallen leaves were carpeting the forest floor with various shades of yellow, orange and brown.

I estimated that perhaps just half of the leaves had been shed by the trees so far, and this meant that within a few days the layer of leaf litter on the forest floor would be even denser, when the rest of them fell. Once the leaves are on the ground, fungi and bacteria begin the process of decomposition, breaking down the organic compounds in them, so that they can be made available for use by other organisms in the forest. Because the tree roots extend deep into the soil, drawing up nutrients into their leaves, these become available on the surface every autumn, and this is a key part of the continuous cycling and recycling of organic matter within the forest ecosystem.

Because the early autumn was drier than usual, it’s not been a great year for fungi, but, as I was about to discover this day, there were quite a lot of fungi visible now, after more sustained and heavy rains in early November. These included a bonnet fungus (Mycena abramsii) on a moss-covered log, that was a close relative of some common bonnet fungi (Mycena galericulata) that featured in my last blog.

This species has not yet been given a common name, and to my untrained eye, it looked just the same as those I’d seen at Levishie. However, Liz Holden, the expert mycologist I consult for help with fungi, was able to identify this one correctly for me, and I found some other specimens of it fruiting nearby, on the dead wood of an alder tree (Alnus glutinosa). To me, these bonnet fungi look like miniature parasols, and there is a simple elegant beauty to them, which I find very appealing.

 

 

 

 

 

 

 

 

 

As is often the case, now that I’d seen these small fungi,  I was beginning to get my eye in for tiny mushrooms, and nearby I spotted some unusual white fungi on another piece of dead alder wood.

These had distinctive patterns of folds or ridges on the underside of their caps, and I realised that this was a species I’d not come across before. The caps were very small in size and it was only by looking at them through my hand lens, and by taking these close-up macro images, that I was able to see the intricate detail and patterns of their shapes. When I sent the photographs and a sample specimen to Liz, she identified them as a species called Plicatura crispa, which currently does not have a common name.

The piece of alder wood they were fruiting on had been turned upside down, as the folds are actually on the underside of the caps, but I took these images from that orientation, to show them in the way I found them.

 

 

 

 

 

 

 

While I was photographing these fungi, I noticed at a certain point that a small beetle had got on to my camera somehow, and was crawling around on it. This seemed quite unusual, as most invertebrates had disappeared by this time of the year, with the adults either dying off, or their larvae going into pupal forms for overwintering. This beetle was rather sluggish, and I was able to transfer it to a fallen hazel leaf and take some photographs of it there. It was subsequently identified for me by Sholto Holdsworth, a coleopterist at the Natural History Museum in London, as being a dung beetle (Aphodius obliteratus).

Nearby, my attention was drawn by some bright orange fungi that were growing out of the broken stem of another alder tree beside the burn. I recognised these as being the alder bracket fungus (Inonotus radiatus), as I’ve seen, and photographed, them before, both at Dundreggan and in Glen Affric. They occur on dead or dying alders, and can persist for several years, although these ones looked quite fresh, because of their bright colour. As with many species in recent years, the scientific name for the alder bracket fungus has been changed, and it is now known as Mensularia radiata.

The colour of these brackets seemed particularly vivid and contrasted with the green landscape, characterised by the moss that was growing on the trees, the rocks and the ground all around. Another group of the same fungi were fruiting lower down on the broken trunk.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In between finding and photographing fungi, which was rapidly, albeit unintentionally,  becoming the main focus of my day, I stopped occasionally to appreciate the patterns made by the fallen hazel leaves on the vegetation they had landed on, such as common haircap moss (Polytrichum commune).

 

 

 

 

 

 

 

In one place, a large patch of one of the dog lichens (Peltigera membranacea) was growing amongst the moss on a large fallen log. Fully hydrated by the wet weather, it looked vibrant and very healthy, with its dark-coloured thallus (as the main body of a lichen is called) contrasting with the reddish-brown apothecia on the lobe margins and the pale grey needle-like rhizines protruding downwards on the underside of the thallus.

Dog lichens are amongst my favourites from the group of symbiotic organisms that are lichens, all of which consist of an intimate partnership, or mutualism, between a fungus and an alga, and in some cases including a third partner – a cyanobacterium – as well. One of those lichens with three partners is tree lungwort (Lobaria pulmonaria), which thrives in the remaining pockets of temperate rainforest in Scotland, and I came across a good colony of it on the trunk of a hazel nearby.

As I walked around, the luxuriance and lushness of this small area really touched me. Layers of moss covered many of the trees and their branches, as well as the fallen trunks of dead trees and rocks on the ground. Like the area at Levishie that I wrote about in my previous blog, this little patch of temperate rainforest is a more easterly outlier of the Celtic rainforest that was formerly abundant on the west coast of the Highlands, but has now been reduced to small, scattered and isolated fragments.

It was definitely becoming a day for fungal finds though, and some purplish shapes on a fallen hazel branch drew my attention as I walked past them. Although they were quite small, their colour made them stand out from their surroundings, and again this was a species I hadn’t seen before. Liz Holden identified them from my photos and samples as being hazel woodwart (Hypoxylon fuscum), which is apparently common and ubiquitous on hazel throughout the UK. This left me wondering why I haven’t noticed it before?

Stepping back across the burn again, some white fungi on another piece of dead wood caught my eye, and when I looked at them more closely, I noticed that they had a very interesting structure to them, being quite porous on their surface. One of them was also slightly blueish in colour, and this was a clue to their identity – Liz confirmed that they are a species called the blueing bracket fungus (Postia subcaesia).

This species occurs on the dead wood of deciduous trees, and is saprotrophic, meaning that it helps to decompose the woody structure of the log. It is part of the community of organisms that recycle and recirculate the nutrients that had accumulated in the tree during its life, playing a vital role within the forest ecosystem. A closely-related species, called the conifer blueing bracket (Postia caesia) fulfils a similar function for the dead wood of coniferous trees.

While I was photographing these fungi, my attention was drawn by some movement amongst the leaf litter, and I was surprised to see a small metallic green leaf beetle crawling around. Sholto was able to identify this for me from my photographs as being a widespread and common species called Chrysomela aenea. According to the Coleoptera website, it occurs in shady woodlands by watercourses, so this was the right habitat for it, but the website states that adults go into hibernation from late August, so it was quite unusual to find this individual still active in November!

With my attention focussed on the forest floor to photograph this beetle, I noticed some more tiny white fungi, fruiting on a small stem – what was probably the petiole, or stem, of a fallen leaf that had already decayed. I recognised these as being parachute fungi, a group of small mushrooms that fruit from leaves and other decaying organic matter in a very characteristic way.  There are quite a few species in this genus, but Liz was able to identify these ones as being the leaf parachute fungus (Marasmius epiphyllus).

Walking a little further downstream, I found a moss-covered log with a lot of bracket fungi fruiting on it. I took a number of photographs of these, but didn’t collect any specimens, thinking that it would be straightforward to get them identified from the images. However, when I sent the photos to Liz, she replied that they were most likely a species of Ganoderma, but she’d need an example to be certain of that. As bracket fungi like these persist for a long time, I’ll make a return visit to Inverfarigaig in the near future and collect a sample to send on for identification …

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This was an area of the woodland with particularly dense stands of hazel, and there were large patches of tree lungwort (Lobaria pulmonaria) there, both on the trees and on some fallen branches, giving it a particularly strong appearance of the green interior of the temperate rainforest ecosystem.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It was getting towards time to leave, as the daylight was fading and I began to retrace my steps, passing once again by the log that had all the bracket fungi on it. Coming from a different direction, I noticed something I’d missed before – a group of tiny orangeish-red blobs on the side of the log. I recognised these immediately as being the sporocarps, or fruiting bodies, of a slime mould – one of my favourite groups of organisms.

They were also a species of slime mould – Trichia decipiens – that I know and can recognise easily, because of the sporocarps’ colour, shape and growth habit. These are nearly spherical in shape, bright and almost luminous in their hue, and attached to their substrate by pale, semi-transparent stalks. All these attributes give them a special character and ‘species personality’ that is very appealing to me. The miniature beauty of this organism speaks eloquently to me of the endless diversity and wonder of Nature.

On my way back up out of the woodland, I stopped by a moss-covered log, where there was another, and much larger, patch of the dog lichen (Peltigera membranacea) that I’d seen earlier in the day. This one was almost completely engulfing the mossy log it was growing on, and was at least 50 cm. by 40 cm. in size – easily the largest colony of this lichen I can remember seeing anywhere. Like the other patch, it was fully hydrated and very lush, almost tropical-looking, in appearance.

What was most impressive about this colony, due to its size, was the sheer number of rhizines that were visible on the undersides of the upturned edges or lobes of its thallus.

 

 

 

 

 

 

 

Resembling miniature, rapier-thin icicles, the rhizines are actually hair-like structures that anchor the lichen to its substrate – the material the lichen is growing on, which in this case was the moss-covered log. This particular species of dog lichen has some of the most visible and spectacular rhizines of all, so I made the most of the opportunity afforded by this colony to photograph their dramatic appearance in close up.

This proved to be a fitting finale to my day at Inverfarigaig, and although I hadn’t explored much of the site, I had found a lot of interest in the small area I’d spent my time in. Like so many places I visit, I’ll have to make some return trips in future to explore the woodland there more fully, and this time I won’t be leaving it another 20 years before I’m back there again.