Summer day in Glen Strathfarrar

On the 20th of July I went out to Glen Strathfarrar for the day with my partner, Pupak, and an old friend, Sharon, who used to live at Findhorn, and did some volunteering with me in the very early days of Trees for Life, back in 1989. Neither of them had been in to Glen Strathfarrar before, so it was a chance to introduce both of them to the beauty of the area, and to the native pinewood remnants there.  It was some months since I’d been there myself as well, so it was a good opportunity to enjoy the fullness of summer in one of my favourite old pinewood areas.

I stopped the car near a small footbridge over the Farrar River, so that we had the option of exploring either the south or north sides of the glen – the bulk of the old pinewood area is on the south side, but the road itself runs just to the north of the river. Stepping out of the car, our attention was almost immediately taken by the movement of a large beetle on the ground. It had a blue edge to the outside of its elytra, or wing cases, and this indicated that it was Carabus glabratus, one of the common large species of ground beetles that occur in the forest.

Pupak and I opted to stay on the north side of the river, while Sharon crossed the footbridge to explore the pinewoods on the other side. There are some smaller stands of Scots pines (Pinus sylvestris) on the north side as well, and we walked amongst a group of them in a section where there’s a steep slope dropping down to the river itself. One pine in particular was of special interest, because it had grown right beside a large triangular-shaped rock, and the lower section of its trunk seemed to have grown around the rock itself.

We spent a while exploring this tree, marvelling at the adaptability of the pine in adjusting to the presence of the rock where it had grown. It had made the most of its unusual circumstances, forming a visually interesting juxtaposition with the rock in the process.

 

 

 

 

 

 

 

Another Scots pine nearby was slightly lower down the slope towards the river, and this meant that its upper branches were just at eye level from where we were standing. It was one of those trees with particularly bright orange-red papery bark on its branches, and these formed a sinuous, undulating pattern as they seemed to be literally reaching over each other in order to gain access to the light, where there was a gap in the canopy of the tree.

 

 

 

 

 

 

 

As in all the old remnants of the Caledonian Forest, each of the mature pines had a unique shape and character of its own – they are as individual and different as each person is.

On one of them, part way up its trunk, there was a distinctive bracket fungus fruiting. This was Phellinus pini, a common species on Scots pines in Scotland, and which also occurs on various other conifer species throughout the northern hemisphere. It is pathogenic, meaning that it eventually leads to the death of its host tree by causing rot in the heartwood. However, it can be many years before the tree actually dies from an infestation of the fungus.

The pine with the fungus had an attractive pattern of plates on its trunk, and on another nearby tree, overlooking the Farrar River down below, the bark pattern was even more pronounced. The irregularly shaped plates were separated by vertical fissures which can be 2 or 3 centimetres in depth, and which create a good habitat for insects, spiders and other invertebrates to live in. The reddish colour of the bark contrasted with the silvery-grey colour of the lichens growing on the plates, forming aesthetically interesting juxtapositions all up the trunk of the tree.

With all the pine trees in this spot, there were plenty of fallen cones on the ground, and in amongst a few of those I spotted a tiny Scots pine seedling. It was only a few centimetres in height and must have germinated a few weeks previously, as its needles still hadn’t straightened out fully. It looked very delicate and vulnerable there on the forest floor, and I wondered what its chances were of growing to maturity, and becoming a large tree like those all around it. Its destiny would depend almost certainly on whether it escaped the attentions of the red deer (Cervus elaphus) in the glen …

There were some birch trees (Betula pendula and Betula pubescens) in amongst the pines, and on the trunk of one of those there was a nice patch of cudbear lichen (Ochrolechia tartarea).

 

 

 

 

 

 

 

This is a common lichen species in the forest, and is one of the most easily identified, as it has brown disc-shaped apothecia, sometimes called ‘jam tarts’, spread across its thallus (as the main part of a lichen is known). These release the spores from the fungal partner in the symbiotic organism that is the lichen – the other partner is an alga.

Also nearby, we came across the sucker or ramet of an aspen tree (Populus tremula). This is a young shoot growing off the roots of a parent tree, and is the main way by which aspen propagates itself. The suckers can grow very quickly, because they have access to all the food resources of the mature aspen they are growing from. They also have a different leaf shape to the mature trees, with the characteristic rounded shape being replaced by pointed leaves on the ramets.

The sucker was growing off the roots of a mature aspen that was overlooking the river, and I spent a little while searching its leaves for evidence of invertebrates feeding there. A tell-tale sign was two leaves that had been ‘glued’ together, or ‘spot-welded’, with white spots of sticky fluid, to create a sheltered and invisible feeding position for a caterpillar. Prying the leaves apart revealed the larva, which was of the poplar lutestring moth (Tethea or) – a common species that feeds on aspen in the Highlands.

On another leaf I found a different caterpillar – a larva of the poplar grey moth (Acronicta megacephala). This was surrounded by a large area of the leaf exhibiting feeding damage – the green surface of the leaf had been eaten away, leaving a brown network of veins. The caterpillar itself was in a slightly curled up position, with its head turned back to form a ‘question mark’ shape – this is a characteristic feature of the species.

There was more feeding damage visible on another leaf, but in that case it was due to the action of a different invertebrate species. Two larvae were feeding on the leaf, and I recognised these as belonging to a leaf beetle (Phratora vitellinae) that is common on aspens, and which I’ve been photographing regularly over the past few years. I’d seen them on an aspen in Glen Affric earlier in the month, and wrote about them in a recent blog.

Near where the aspen was growing, there was a small clearing in the forest – the wetter soil conditions were not suitable for trees to grow there. Such clearings contain a different suite of species to the woodland, including the heath spotted orchid (Dactylorhiza maculata), and several of those were in full bloom.

This is the most common orchid in our area, and it’s widespread and abundant in early July, which is the peak of its flowering season.

 

 

 

 

These ones were a little late in the season in flowering, but I was very pleased to have the opportunity to photograph them in the second half of July.

Just as I was about to take a close up image of one of them, a fly landed on top of the flower, as can be seen in the photograph above, to the right. This was of particular interest to me, as Graham Rotheray, an entomologist based at the National Museum in Edinburgh, has been doing a survey (partly at our Dundreggan Conservation Estate) on the insects that pollinate the heath spotted orchid. He identified the fly from the photo, and said he’s seen it on orchids before, but that it doesn’t enter the individual flowers and therefore does not perform the function of pollination.

By now it was almost time for us to meet up with Sharon again, so Pupak and I headed back towards the car. The sun had come out by this time, and we paused to appreciate the backlit leaves of an old oak tree (Quercus petraea) along the way. Earlier I’d noticed some galls on an alder tree (Alnus glutinosa) beside the road not far from where we’d parked, so I stopped to take some photographs of those as well.

These galls are induced by a mite (Eriophyes laevis), and take the form of raised pimples on the upper surface of the leaves. Each pimple contains a larva of the mite, and on some leaves there can be dozens of these galls clustered together.

 

 

 

 

 

 

 

Back at the car, we decided to drive further west in the glen, so that Pupak and Sharon could get a sense of the rest of the forest there. With the blue sky and sunshine, it was an ideal opportunity to appreciate the area, which rivals Glen Affric for the beauty of its pinewoods, in my opinion.

 

 

 

 

 

 

 

 

 

 

 

 

 

We drove up to the end of the road, past the two dams that have created Loch Monar, to an area where there are just a few remnant birches clinging on to their last root-holds on an otherwise completely deforested hillside. I find it very sad to see such degraded landscapes, but doing so also renews my commitment and dedication to the work of Trees for Life, in helping to restore the Caledonian Forest in areas like this.

After those sobering few minutes of being in a place where the forest is still in decline, we headed back eastwards down the glen. Our spirits were renewed when we stopped briefly to look at an island in the middle of Loch Beannacharan. This small island is completely covered in native pinewood, reflecting the fact that deer rarely if ever go there, and in the absence of overgrazing, healthy growth of trees has occurred. This graphically illustrates how the land can recover, and was a fitting image to take back with us, after a great day in the glen.