Beside the River Moriston

One week-end in the middle of February I was on my way out to Glen Affric for the day. Leaving Loch Ness at Drumnadrochit, I headed up Glen Urquhart towards Cannich, but the road was blocked at Balnain. There was a large rallying event taking place there, and a combination of cars parked beside and on the road and many people walking on the road meant that no traffic was able to proceed. After waiting for a short while, with no sign of any forward movement on the road, I turned around. I headed back down towards Drumnadrochit, and, changing my plans for the day, decided I would go to a very nice area of native woodland beside the River Moriston, downstream from Dundreggan, instead.

This change of plans, and the delay in Glen Urquhart, shortened my day, but it was the right decision, because when I got home that evening I discovered there had been a fatality at the rallying event – a car had gone off the track and hit a spectator, which was why the road was blocked. Very sad indeed, and the rally was abandoned, but meanwhile I continued on down to Glen Moriston unaware of the tragedy, and spent the rest of the day on a section of the river I’ve blogged about before, just below the dam and about a mile from our Dundreggan Estate.

There are some interesting rock formations there, where the river tumbles over some cascades, and a wide range of native trees, including Scots pines (Pinus sylvestris), oak (Quercus petraea), ash (Fraxinus excelsior), juniper (Juniperus communis) and aspen (Populus tremula) as well as a good density of wood ant nests (Formica lugubris). It was the aspen trees that attracted me initially this day – it’s a species I’ve been spending a lot of time with recently.

There are quite a lot of relatively young aspen trees there, growing in amongst some larger Scots pines, and as I wandered around I noticed there were some fungi fruiting on several pieces of dead wood on the forest floor. As fungi are always of interest to me, I stopped to have a look, and ended up spending quite a while in one place in particular. A large woody bracket fungus on a fallen aspen branch was the most conspicuous of the fungi, and this was the aspen bracket fungus (Phellinus tremulae).

This species was only recorded for the first time in the UK in 2000, when it was discovered at the RSPB’s Insch Marshes Reserve in Strathspey, but it has subsequently been found to be quite widespread on aspen in the Highlands. We’ve seen it in both Glen Affric and at Dundreggan, with the records there being probably the most westerly for the fungus in Scotland. This sighting here, beside the River Moriston is about a mile east from where I’ve seen it on Dundreggan …

A few feet away, on another fallen branch from one of the aspens, I spotted a different fungus – one which I didn’t recognise. I took some photographs and also collected a sample, which I sent to Liz Holden, the mycologist who helps me with fungal identifications. She replied that it is a crust fungus (Peniophora polygonia), and when I subsequently did a web search for this species, I found a reference to it having metabolites that are active against the decay action of the aspen bracket fungus (Phellinus tremulae) – very interesting! At the time of writing this blog, I’m waiting to receive the scientific paper which contains the details of this relationship.

As is often the case, the more time I spend in a small area in the woodland, the more things of interest I see. Another nearby fallen aspen branch turned out to have another different fungus growing on it. Again, I had to rely on Liz for help, and she provisionally identified it as being the poplar bracket fungus (Oxyporus populinus). She wasn’t able to confirm this for certain though, as it was fairly young material and hadn’t yet produced the spores that are necessary to see for making a definitive identification.

Literally just a couple of feet away from this suspected poplar bracket fungus, I spotted some tiny white blobs on a small piece of fallen aspen wood – a section of branch about 2 cm. in diameter. Looking at them through my hand lens, they looked very interesting and distinctive, so I spent a while taking a series of photographs of them with my high-magnification macro lens. I also collected some samples to send to Liz, and when she replied it was with some considerable excitement, as she thought it was a species (Calathella eruciformis) that hadn’t been recorded in the UK before.

The host species for this fungus is aspen, but Liz felt she needed a second opinion before confirming the identification, so she sent the specimen off to an expert at Kew Gardens in London, to seek his views on it. When he replied, it was with confirmation that it is indeed the first record for this fungus in the UK. It had taken me about half an hour to get some good photographs with my macro lens, because the fungi are so small, and I subsequently had to use focus stacking software to produce the extreme close up images here. However, it was well worth the effort in doing this, to have good photographs of this discovery.

 

 

 

 

 

 

 

 

 

In amongst the aspens where I’d found all these different fungi, there was a Scots pine, and it too had some fungi growing on it. These were on the trunk of the tree itself and Liz confirmed their identify as being the benzoin bracket fungus (Ischnoderma benzoinum) – another species I wasn’t familiar with.

 

 

 

 

 

 

 

The pine also had some nice patches of moss on it, which made for an interesting contrast with the pattern of plates on the tree’s bark.

 

 

 

 

 

 

 

On the ground nearby, there was a large patch of big shaggy-moss (Rhytidiadelphus triquetrus), and some aspen leaves had fallen on it. These were showing the early stages of the decomposition process, as fungi had begun to break down the cells of the leaves, so that the veins in them were much more visible. The leaves would have fallen in early October, so they’d have been lying here for over four months by this time, which gives an indication of the speed at which the recycling of leaves takes place.

Another aspen leaf had fallen on to a piece of dead wood lying on the forest floor, and it was at a more advanced stage of decomposition. There were black blotches of a decomposer fungus scattered across the leaf surface, and much of the leaf had already been reduced to a lace-like filigree pattern of veins, radiating out from the base of the leaf, where it joins the stem or petiole. I wondered if the fact that this leaf was on a damp piece of dead wood had somehow enabled the decomposition process to go more quickly? Perhaps it remained more consistently wet there, whereas the leaves that had fallen on the moss were more susceptible to drying out?

This small area of aspens had proved to be very interesting, and quite a lot of the day had passed while I’d been photographing the fungi etc. there. I took a couple of photos of the stand itself, before turning my attention to the cascades on the river, which was what I’d planned to spend my time with when I’d arrived.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I always find it very peaceful and healing to look out over cascading water in rocky sections of rivers like this – it’s as though the very slow wearing away of the rock by the water has a soothing effect on me.

 

 

 

 

 

 

 

 

 

These photographs were all taken using long exposures, or a quarter of a second or slower, to give the blurred effect of the water in motion. Not only is this aesthetically pleasing (to me at least!) but it also conveys for me a feeling of the power of the water in its ability to shape the rocks, over extended periods of time.

Watching the water flowing amongst and over the rocks gave me the realisation that the same process was at work there as with the fungi that were decomposing the aspen leaves I’d looked at earlier. Everything in Nature is in a constant state of flux, although the time frames in which the changes take place vary by orders of magnitude – relatively quickly in terms of the breakdown of the aspen leaf, but at a geological rate for the erosion of the rocks by the flowing water. As humans, we can directly experience the former. With the latter, however, we can only see the results of past erosion, as it’s not possible with our limited lifespans to see a perceptible difference in the sculpting of the rocks.

Taking a break from watching the cascades, I was attracted to a particular Scots pine that was growing beside a lichen-covered rock. Its trunk was perfectly straight, unlike most of the others in the area, and its bark had very well-developed distinctive plates.

 

 

 

 

 

 

 

It was getting quite late in the afternoon now, and the light would soon be fading, so I walked a little further upstream, where there are some oak trees (Quercus petraea) growing amongst the pines, for my final photo stop of the day. The spray from the cascades on the river creates a permanently moist atmosphere in this narrow part of the glen, so the oaks are festooned with mosses and lichens – it’s a little fragment of temperate rainforest.

There are  some large patches of tree lungwort (Lobaria pulmonaria) growing on the oaks there, which I’ve visited and photographed before, but this day I also noticed some fallen patches that were lying on the ground – these must have been blown down by recent stormy weather.

 

 

 

 

 

 

 

While most lichens consist of a mutualistic symbiosis between a fungus and an alga, tree lungwort contains a third partner as well – a cyanobacterium. This absorbs nitrogen from the air while the lungwort is growing on a tree, and when the lichen falls to the ground like this and decomposes, the nitrogen is added to the soil as a natural fertiliser. Thus, old temperate rainforest patches, which can have an abundance of lungwort growing in them, actively improve the fertility of their soils, through the ability of lungwort to harvest nitrogen from the air.

This brought me back full circle to the theme of decomposition, which had featured earlier in the day. It had been rather an unexpected day too, as my original plan had been to go to Glen Affric. However, as a result of the accident with the rally in Glen Urquhart I’d found the fungus growing on dead aspen wood that hadn’t been recorded in the UK before, so the unexpected turn of events had produced a real gift for me. I’d also enjoyed shooting some video of the River Moriston, so I’ll finish with the edited footage from that:

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