I was on my way to Dundreggan on Saturday, but as I’ve sometimes done before, I stopped beside the River Moriston, at a small patch of beautiful native woodland below the dam on the river, about a mile before reaching Dundreggan itself. This is a beautiful little area, and as has happened on previous occasions, I ended up spending the whole day there, so that I never made it to Dundreggan again.
I stopped there this day because it was beginning to snow as I arrived, and I thought there might be some interesting opportunities for photography, amongst the old pines and oaks that line the river there, and where there are also some nice rock formations. As it turned out, the snow came intermittently in blustery squalls of driving snow, alternating with hail, sleet and intervals of sun in between, so it was a day of constantly changing weather.
I love these days, as the unpredictability of the weather and the constantly changing conditions bring a real sense of wildness to the landscape and often leave me feeling exhilarated from being outside in them. The snow wasn’t lying on the ground at all, except for a few tiny patches that looked like they were left over from the previous night. However, the moisture in the air, and the consequent wetness of the vegetation, brought qualities of vibrancy and luxuriance to the woodland.
I decided to go upstream from the area where I’ve spent time before, scrambling along a steep scree slope of loose rocks. I had to be careful, as the rocks were slippery from the melting snow and sleet, and it was a sheer drop straight into the river below. I could see a twin-trunked oak tree (Quercus petraea) on a rock outcrop a little further along, so I headed for that. It was typical of many such trees in the Highlands, in that it had probably grown there because it was out of reach of deer.
Near the oak there was a young ash tree (Fraxinus excelsior) growing out of the middle of a group of large boulders, and it had several relatively short stems that were rather twisted and contorted because of their situation. My attention was drawn by some dark shapes on the end of the branches, which were just at eye level, because of the tree’s small stature. Looking closely I saw they were galls, and of a type that I hadn’t seen before. Some of the galls were growing around the winged samaras, or keys, that contain the ash’s seeds.
Although I wasn’t familiar with these galls, I felt they were quite distinctive and therefore would be easy to identify. They also reminded me a lot of cauliflower galls that are induced by a mite (Aceria populi) on aspen trees (Populus tremula) that I’ve seen in Glen Affric before. When I got home and looked in my gall guides, I quickly found out that they are caused by a related species, another mite in the same genus (Aceria fraxinovorus), and they are also known as cauliflower galls or ash key galls. They are tough and woody, and can remain on the trees for up to 2 years. They are brown in colour at first, and turn black as they age. There aren’t many ash trees in our Project Area – there’s only a handful of ashes on Dundreggan, and I’ve never seen any of them produce seed yet – so that’s probably why I hadn’t seen these galls before.
While I was looking at the galls, my eye was also drawn to the buds on the ash tree. These are distinctive for being black, making a vivid contrast with the tree’s light-coloured bark, and their colour was intensified by the wetness of the day, so that each bud seemed to be glistening and shiny in its blackness.
It was still snowing intermittently, so I had to take breaks from photography, to prevent my equipment from getting too wet. That gave me the chance to just stand there and appreciate the snow swirling all around, as each squall passed by. The falling snow formed white curtains that drifted past me, drastically reducing the visibility and creating an evocative and mist-like atmosphere in the landscape.
The snowflakes themselves are not visible in this photograph, because of the long exposure, which means they are just a blur in the background. However, when I changed to shooting some video, the falling snow was much more apparent:
Turning to head back in a downstream direction, I stopped to look at some moss-covered oaks I had seen earlier. Viewing them now from the west side, I was struck by how much tree lungwort (Lobaria pulmonaria) was growing on them. The west side is where the prevailing, rain-laden winds blow from, and the lungwort was taking advantage of all the moisture to grow there.
This lichen is considered to be an indicator species for temperate rainforest in the Pacific Northwest of North America, and its presence here is an indication that the narrow gorge of the River Moriston at this point also creates the perfect conditions for temperate rainforest to flourish. In fact as I looked at this tree, I realised it was more densely covered with lungwort than any other single tree I’ve seen in our entire Project Area.
In amongst the tree lungwort were some patches of another closely-related species, textured lungwort (Lobaria scrobiculata), which is affectionately known by lichenologists as ‘lob scrob’. In contrast to the bright green colour of tree lungwort, it is blue-grey and its lobes are less deeply-indented and convoluted, and less fractal, in shape. It is slightly less conspicuous, and it is also possibly less common in our woodlands – I certainly don’t see it as often as tree lungwort.
Some patches of the tree lungwort were covered in brown discs. These are the apothecia, the reproductive structures that release the spores from the fungal partner or symbiont in the lichen. Whereas most lichens consist of a symbiosis between a fungus and an alga, tree lungwort also contains a third symbiotic partner – a cyanobacterium (Nostoc sp.) (formerly known as a blue-green alga).
Like the alga, the cyanobacterium can harvest the sun’s energy through photosynthesis, but it can also absorb nitrogen from the air, thereby providing a net gain of nutrients to the forest ecosystem. Textured lungwort also contains a cyanobacterium (Nostoc sp.), but apothecia are less commonly seen on its thallus (as the main body of a lichen is known). Like tree lungwort, it occurs in large areas of North America and northern Europe.
Somehow, the lobed shapes of both lungworts made me think of snowflakes, in that no two seemed the same. Each one had its own unique and distinctive shape, just as each snowflake is said to be different from every other one.
By this time it was late afternoon and it was still snowing intermittently, so I took a few last photographs of some Scots pines (Pinus sylvestris) growing beside the river. I left for home feeling satisfied and content with another interesting day out in this small patch of woodland – it certainly made up for the fact that I didn’t reach Dundreggan again!