Back in Strathfarrar again

Glen Strathfarrar is unusual amongst Scottish glens in that the road up into it is private, with a locked gate across it, which was closed for the winter, until March 31st. So, with Sunday being the 1st of April I decided to visit Strathfarrar again, for the first time since early November.

It was a very dry day, as we’ve had about 10 days of hot sunny weather, with temperatures reaching 22 degrees Celsius – exceptional for March in the Highlands – and all the lichens, mosses and ferns were desiccated and shrivelled up. A few miles away, in Strathglass I had passed a hillside which had previously been covered in gorse, but the whole area had been burned in a fire that had started there a few days previously, exacerbated by the drought condition – there was a sign warning people of the high fire risk at the entrance gate to Strathfarrar.

I stopped at a small stand of native pinewood beside the River Farrar that I hadn’t explored before, prior to reaching the main pinewood area in the glen. This was a nice group of pines, growing beside a bend in the river, and some of them had their roots exposed, no doubt due to previous floods washing the soil away from around them. I noticed a bracket fungus growing on the roots of one tree, and looking closely I saw that it was a species called Phellinus pini.

This is closely related to both the aspen bracket fungus (Phellinus tremulae) and another species (Phellinus lundellii) which I’d photographed recently at Dundreggan. Because of its tough, woody structure a bracket fungus like this is impervious to drought conditions, and can persist for extended periods of time. The underside of the fungus has a very clear pore structure, which takes the place of the gills in more familiar mushrooms, and serves the same function – releasing the spores that the fungus uses for reproduction.

On a nearby alder tree (Alnus glutinosa) a bright patch of yellow on the trunk drew my attention. It was a lichen (Chrysothrix candelaris) that is common on some of the broadleaved trees in the Caledonian Forest, especially silver birch (Betula pendula) and oak (Quercus petraea). This is an easily identifiable species, although I don’t remember seeing it on alder before. It was looking somewhat desiccated as well, but the yellow colour was undiminished by the dry conditions.

Moving on a little, I spotted a patch of the same lichen growing on the branch of a large Scots pine (Pinus sylvestris) – it’s relatively rare that I’ve seen it on pines. The bright yellow made it stand out amongst the green needles and brick red colour of the young bark on the Scots pine.

One of the pines in the same group had an interesting burl or burr on one of its exposed roots. Such burls are relatively common on the trunks of Scots pines, but its rare to see them on the roots, probably because the roots are underground in most cases. They are apparently caused in many cases when the tree experiences stress such as drought, and the unusual growth formation consists of dormant buds – I included a photograph of a large burl on a birch tree in the previous blog entry.

Some of the young birch trees that were growing amongst the large rocks beside the river had their new leaves opening out already – about two or three weeks earlier than usual. This is due to the exceptionally warm and unseasonal weather we’ve had recently, and I wondered if the fact that the birches amongst the rocks were more advanced than those elsewhere was due to the fact that the rocks absorb and retain the sun’s heat, thereby creating a warmer micro-climate in their vicinity?

This idea was reinforced by the sight of a common dog violet (Viola riviniana) flowering close by. The plant was growing right beside a small rock, and the flower itself was resting on the rock. Could it be because of the extra warmth provided by the sun’s energy being absorbed by the rock that had led to this violet being the first to flower in this area?

There were some interesting rock formations there at the edge of the river, so I spent some time exploring them, and taking a series of photographs. The rocks seemed to provide a good visual complement to the straight-trunked pines in the background.

 

 

 

 

 

 

Just upstream from the rocks there was a still area of water, where there were some mirror-like reflections of birch trees growing on the other side of the river.

 

 

 

 

 

 

When the sun came out for a few minutes I had a closer look at the new leaves on some of the small birches that were growing amongst the rocks beside the river here.

My attention was drawn by an unusual shape on one of the young birches, and it turned out to be the shed skin, or exuvia, of a stonefly larva.  The larvae of stoneflies are aquatic, living in burns and rivers, but they come out of the water and clamber up on to nearby rocks or vegetation, to pupate. That is what had happened here, with the adult stonefly having emerged from its larval skin, which was left behind on the twig like this.

As I looked closely at this stonefly exuvia, I noticed there was something else on the same twig nearby. It was a spider, sitting lengthways on the underside of the twig, so that it was very hard to see. The colour of the spider also closely matched the reddish colour of the twig, adding to the camouflage effect. I had to send the specimen away to get identified, and it has subsequently been confirmed as an adult male of a common species (Metellina mengei).

 

I don’t know if there was a reason for the spider being so close to the stonefly exuvia or not, but they were the only things of note that I saw when I looked at quite a number of birch twigs in that area. I was hoping I might spot some more insects, but none of the other twigs had any invertebrates on them at all, except for a few ants on one young sapling. Was it just a coincidence that they were so close to each other, or did the spider hope to ensnare unwary insects that came to investigate the stonefly exuvia?

I wandered around amongst the Scots pines for a little while longer, enjoying the stately presence they brought to this section of the river bank. They had obviously all grown up together, as they were straight-trunked and of a similar age to each other. There must have been good conditions for tree seedling establishment 150 – 200 years ago, when they were all young, unlike in much of Strathfarrar today, where overgrazing by deer and sheep prevents almost all regeneration outside fenced exclosures.

We’ve now got agreement from one of the landowners there though to put up a fence to allow an area of 14 hectares to regenerate naturally. The old pines there were killed by a fire in the 1960s and no new trees have become established since then, but there are seedlings there, waiting for a chance to grow, which our fence will give them the opportunity to do. We’re still looking for some money to fund the fence, so if you’d like to help, please visit our Strathfarrar appeal page and make a donation – my thanks for any support you can give.

While I was looking at these pines, I noticed a strange pattern of growth on one of them –  a large umbrella-shaped cluster of dense branches and needles, growing out from the trunk, partway up one of the large trees. I don’t know what causes this, but having seen a similar distorted shape of branches and needles on a Scots pine in Glen Moriston recently inspires me to do some research to see if I can find out what makes the pines grow in this way.

At this point I decided to go further up the glen, to the main area of native pine woodland a little further west. However, as it turned out I didn’t make it that far! I had gone less than a mile when I saw a cluster of blackthorn trees (Prunus spinosa) in full flower right beside the road, so I stopped there to photograph them. We have quite a lot of blackthorn on Dundreggan, but I hadn’t been aware of any in Strathfarrar before, so I was very pleased to see them there.

They were also growing amongst one of the few patches of juniper in Strathfarrar. Although juniper is unusually abundant on Dundreggan, there are very few junipers in either Glen Affric or Strathfarrar, and the reason for this variation between the glens in unknown – a mystery the solution to which is still waiting to be revealed or discovered!

Blackthorn is one of the trees that flowers before it gets its new leaves in spring, and the large white flowers therefore are quite dramatic and spectacular. This strategy may have evolved to make the flowers more conspicuous to the insects that the tree relies upon for pollination. Like many other plants this year, the blackthorn’s flowering period is at least a couple of weeks ahead of normal – this is due to the exceptionally warm weather we had in the second half of March.

By this time, it was after 5.30 pm, and I had to turn around, as I needed to be back out of the gate on the road by 6 pm, when it closes for the night. I was a little sad to leave Strathfarrar that day, because spring was bursting out all around, but I’ll be back again in about 4 weeks. I’m walking one of the overnight legs on our special Treelay event, to help celebrate the planting of our Millionth Tree, and my leg goes from Glen Affric to Glen Cannich and then into Strathfarrar. This is a sponsored event to raise money for the next stage of our work, so if you’d like to sponsor me on the Treelay, you can do so by going to my fundraising page on the Just Giving website. I’ve set myself an ambitious fundraising target, so I’m hoping for lots more support!

As has become the norm on my days out in the forest now, I was also filming some video during the day, so here’s a short compilation clip of the best footage:

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Once I was out of the gate, I decided to stop a couple of miles away, on my way home, at a small stand of native woodland beside the road in Strathglass (the Farrar River discharges into the Glass). I’d driven past that bit of woodland countless times over the years, without ever walking in it, so this was the day to change that! It’s a nice area of mainly mature oaks, but unfortunately I couldn’t see any sign of young oaks there – the only young trees were of sycamore and beech, neither of which are native to the Highlands.

However, there were plenty of native flowers blooming on the forest floor, particularly wood sorrel (Oxalis acetosella) and wood anemone (Anemone nemorosa), and their delicate blossoms provided a fitting finale to my day.