After spending the night in the Alltbeithe Youth Hostel, my colleague Mick Drury and I went in different directions, to visit some of the other exclosures on West Affric. We’d had a good night in the hostel, talking with the warden and some of the other hikers staying there, including Tony Hunter from Liverpool Museums, who’s doing some follow up sawfly survey work for us on Dundreggan this year.
I headed west on the path that goes to Camban and through to Loch Duich, and this follows the Affric River for the first section. My first stop was going to be some small stock-fenced exclosures that we had erected around isolated and overgrazed eared willow seedlings (Salix aurita) in 1996 and 1997. On the way I passed some peat hags – areas of eroded land, with the stumps of old Scots pines exposed amongst the peat – evidence of the existence of forest in this part of West Affric in the past.
In complete contrast to the deforestation represented by the peat hags, one of the stock-fenced exclosures has produced a particularly dramatic result – I saw bluebells (Hyacinthoides non-scripta) flowering there when I visited in 2004. This was quite astonishing, as the next nearest bluebells in Glen Affric are about 20 km. to the east, near Dog Falls!
In 2004 I had only seen a few bluebells there, but on my subsequent visit in 2008 I had counted about 70 flowers. There were even more this year – I estimated over 100 flowers altogether – and in addition to those inside the fence, a few were blossoming outside, between the fence and river, where they must have escaped the attentions of the deer.
How have these bluebells come to be here? Did their seeds somehow get transported the 20 km. from further east in the glen? I have no answer to this question, but the bluebells’ presence there is a remarkable testament to Nature’s ability to respond when we work to help the restoration of natural ecosystems. Also, it’s not just bluebells that are flourishing in that exclosure – during my last two visits I’ve seen wood anemones, angelica and slender St. John’s wort all thriving in this tiny fenced area. It’s a stunning example of the recovery of the diversity of life when we remove the pressure of overgrazing, and visiting these bluebells was the main reason for the timing of my visit to West Affric in early June this year.
Looking north from the location of this precious little patch of bluebells, I had a good view of another area we fenced for natural regeneration in 1994 – Allt Beithe Garbh. That’s a 9.5 hectare exclosure that I planned to visit later in the day, but looking now from a distance, it was quite clear to see the difference in vegetation between the inside of the exclosure and outside. It’s another island of new life and diversity in the otherwise monotonous, uniform landscape of grass on West Affric.
A short distance west of the bluebell patch, three different tributary burns come together to form the Affric River itself, and there are some interesting rock formations just downstream from that point. I stopped to take a few photographs, and ended up spending quite a while there, because it was so beautiful in the morning sunshine.
It was a rare wind-still day with clear views to the west, so I took some time to explore the rock formations and enjoy the special qualities of the place. In one place, the flow of the water over centuries and millennia had eroded the different layers of rock, creating beautiful shapes that were very organic in their form.
This is one of the few areas on the upper Affric River where the underlying rocks are exposed, and where the flowing water has been able to work its magic in sculpting beautiful shapes, as the surface of the rocks has been eroded over the millennia.
While I was there, I also took the opportunity of shooting some video footage:
Heading further west again, I crossed the river on a small footbridge and came to some other small stock fenced exclosures we’d put up in the 1990s, to enable the few eared willow seedlings in the riparian area beside the river to grow without being overgrazed by red deer (Cervus elaphus). In one or two of the exclosures, the willows had hardly grown at all, and were still just a few inches tall. However, in others the willows were quite large, and, as I discovered, supporting a lot of insect life.
The willows were tallest in the centre of their respective fenced areas. The outer parts of each bush, where they were beside the fence, were trimmed at exactly the height of the fence, because the deer can reach them there. This is a lesson to learn for future stock fenced exclosures like this – we need to make them larger, so that the deer can’t reach over the fence and browse the willows that are inside!
It was the middle of the day by now, so I stopped beside the largest of the eared willows and ate my lunch, while I looked at the bush itself. Eared willow is a dioecious species, meaning that individual plants are either male or female, unlike most trees such as birch, oak etc which have male and female flowers on every individual. This one was a female, and it had quite a lot of flowers on it.
As I looked at the flowers I began to notice lots of insects on the bush. A mayfly was perched on one of the leaves, and I saw several different species of caddis fly as well – they spend the first part of their lives as larvae living in freshwater, often creating elaborate ‘cases’ within which they can feed unseen by predators. The adults I saw on the eared willow had probably emerged recently from the river, and were using the bush as a place to perch.
I made a provisional identification of one of the caddis flies as being Philopotamus montanus, a species that breeds mainly in swift, upland streams, which describes this site on West Affric well. However, I’ll have to send that one, plus the other caddis flies and the mayfly, off to an expert to get them identified.
As will be obvious from my other recent blogs, I’ve developed a keen interest in aphids of late, and as I looked closely at this eared willow I was delighted to see some aphids on it. These seemed quite distinctive, with orange-coloured nymphs and green adults feeding together on the stems of the willow. Later, I was able to identify them as being the small willow aphid (Aphis farinosa) which is common on willows, and this was confirmed by Ed Baker, who helps me with aphid identifications.
As I looked around the eared willow bush, I saw more and more of the aphids and I began to get a sense of how much life this particular willow was supporting. Given its situation, as one of the only a handful of willows growing successfully in the upper Affric River watershed, the importance of our work in enabling this bush to regenerate became all the more apparent.
With my eye in for spotting the aphids on the bush, I also noticed that in a number of places they were being tended by ants. These were a type of red ant (Myrmica sp.), which feed on the honeydew excreted by the aphids as a waste product. Ants actively ‘farm’ aphids like this, and provide some protection against parasitic wasps, which lay their eggs in aphids – the wasp larvae then grow within the aphids, killing them in the process.
As I continued to look at the aphids on the various parts of the willow bush, I saw an Ichneumonid wasp crawling around amongst some of the aphid-covered stems. However, this was too large a wasp to be one that parasitises the aphids – it was probably looking for other insects to prey upon. By this time I was almost overwhelmed by the variety and numbers of insects feeding on this one willow bush, and it made me think about how much life there could be there, if we could get more trees growing in the riparian zone along the upper Affric River.
After more than an hour well-spent with the eared willow, I walked westwards again to my furthest-most destination that day – a clump of young rowan seedlings growing beside the track that leads to the Camban bothy. These rowans are a particularly sad sight, and provided a sobering contrast with the life on the eared willow. I’ve been visiting and photographing this clump of rowans since October 1992, when I first visited West Affric, during an attempt to purchase the estate from the previous owner. I’ve returned approximately every four years since then, and on each occasion the situation has always been the same – the rowans have been repeatedly eaten back by the deer, and are unable to grow at all.
Despite the intentions of the National Trust for Scotland (who own West Affric) to reduce deer numbers so that regeneration of the vegetation can occur, they’ve been unable to achieve that result.
The full sequence of photographs I’ve taken of these rowans over the 20 year period can be seen here.
From there I headed back east again, walking around the base of Beinn Fhada towards the Allt Beithe Garbh exclosure that I had seen earlier in the day. On the way, I came across a large area of peat hags – land where the surface vegetation has become broken and the rain and wind has eroded the underlying peat, leaving large bare patches that are like open wounds or running sores in the landscape.
Peat hags like these are always a depressing sight for me, not only because they are like tree graveyards or forest cemeteries, but also because they show the extreme effects of overgrazing. In a balanced ecosystem, such bare ground would soon be colonised by new plants, which would grow over this wound in the earth, covering it in vegetation again. I’ve seen this happen in places such as the Athnamulloch exclosure at the west end of Loch Affric. In the years since it was fenced in 1990, the peat hags there have been completely revegetated, although where they extend outside the fence, they are still just as bare and barren as these ones on West Affric.
The full visual impact of the peat hags is even more apparent in these video clips:
Leaving the peat hags behind, I walked across the flat section of the glen, crossing the river and approached the Allt Beithe Garbh exclosure. On the way, I came across a nice cluster of common butterwort plants (Pinguicula vulgaris) that were in flower. With their five green leaves radiating out from a central point, I always think of butterworts as being like small green starfish out of water. Like sundews, they are insectivorous plants, catching small insects on their leaves, where they are slowly digested. Their purple flowers only last a for a short period, but provide a bright splash of colour that contrasts vividly with their leaves.
Reaching the Allt Beithe Garbh exclosure, I took some more photographs at a couple of places where I’ve been taking photos over the years since the fence went up in 1995. Like the Coire Ghaidheil exclosure that Mick and I had visited the previous day, this was one planned for natural regeneration only, as there were a straggle of trees still surviving up the sides of the burn which gives the exclosure its name.
Some regeneration has indeed taken place since then, and a series of photos of the area can be seen here. However, when we did a survey of the area about 10 years after the fence was erected, we found that 80% of the trees growing in the exclosure were rowans. This is not a natural balance of tree species in our native forests, but is a result of the absence of seed sources nearby for other tree species. Rowan seeds are carried in the stomachs of birds that eat rowan berries, and germinate in the birds’ droppings, which is why rowans have been successful in growing there.
As I walked around in the exclosure, it was very apparent that the same situation prevails now – the vast majority of the trees that are getting established there are rowans. We’ve proposed previously to the National Trust for Scotland (NTS) that some other species, particularly downy birch and eared willow, should be planted there to give the young forest a more natural composition of trees, and after this visit we’ll make the case for that again. Mick’s surveys of some of the exclosures where we planted trees on West Affric in the 1990s have shown there’s a need for some follow up planting in them, because of natural losses in some cases and the impact of deer in another, where they got into one of the exclosures when the fence was damaged by snowfall. We’ve got provisional agreement from NTS to do that in 2013, so I hope we’ll be able to do some planting in Allt Beithe Garbh at the same time.
By this time it was late in the day, and the memory card in my camera was completely fully – the first time that has happened (it was die to shooting a lot of video on the day!) – so I began the long walk back to my vehicle at Athnamulloch. I left West Affric with mixed emotions that day – inspiration and joy at the growth of trees I’d seen, at all the insect life on the eared willow, and at the abundance of bluebells in that one tiny exclosure. However, this was tempered by the sight of the overgrazed rowan seedlings I’ve been documenting for 20 years, and at all the peat hags – there’s still a lot of work to do before West Affric will be restored to ecological health and a more naturally-vegetated condition.