West Affric is a 10,000 acre estate owned by the National Trust for Scotland (NTS) that encompasses the headwaters of the Affric river watershed. Trees for Life has been involved as a partner in forest restoration on the estate since it was purchased by the Trust in 1992, and we planned and implemented a series of 10 exclosures there, for both natural regeneration and tree planting, in the period from 1993 to 2000.
West Affric is probably the most remote site where we’ve worked, and although I aim to get out there regularly to check on how the trees are growing, it works out usually that it’s about once every 4 years when I make it. As my last visit had been in July 2008, I’d been planning a trip out there this year for some months, so in early June my colleague Mick Drury and I went to spend 2 days on West Affric, to look at how the trees were doing in the various exclosures.
Access to West Affric from the east entails driving to Athnamulloch on Forestry Commission Scotland land in Glen Affric, and then walking west for about 3 miles to reach the boundary of West Affric. On the way, we could see the trees we planted in the early 1990s in the Athnamulloch exclosure, which is situated just to the west of the bothy that gives the area its name. West Affric itself begins at the Allt Coire Ghaidheil burn, which has a nice footbridge across it surrounded by mature rowan trees – they were in full flower when we visited.
The burn flows down from the hills through a section of gorge, and that contains the greatest numbers of trees on West Affric, which is otherwise almost completely deforested in its 10,000 acres. The first project we did with NTS therefore was to put up a fence for natural regeneration there, encompassing 9.5 hectares, and this area is probably the most dramatic in terms of the return of the forest, as a result of that.
Because it’s also the first exclosure reached on West Affric, it tends to be the one I visit and photograph the most, and I’ve built up a series of images of the same scenes, photographed over the years, to show the results of our work. One of the purposes of this trip therefore was to take new versions of those same photographs, to provide a visual comparison of the growth of the trees and other vegetation that is taking place there.
It was particularly impressive to see the large blaeberry plants (Vaccinium myrtillus) flourishing there, as they are a characteristic woodland species, and illustrate the fact that it is not just the trees that are regenerating there, but the whole forest ecosystem. The gorge provides a sheltered location from the prevailing westerly weather, and it is this I believe that enabled the trees to survive there, and is now speeding the recovery of the forest.
Near the top end of the exclosure there are also some tea-leaved willows (Salix phylicifolia) – a scarce species in the glens where we work – and they were in flower when we visited. During previous visits I had seen perhaps four or five different bushes, but this time Mick and I spotted at least ten separate plants, so the species seems to be spreading there.
Heading downstream on the west side of the burn, I came to a point where there was a good view over much of the exclosure. This showed not only the young birches, rowans and willows that are growing successfully, but also how heather (Calluna vulgaris) is taking over, replacing the grass that predominates outside the fence. This is the natural process of ecological succession occurring once again – in the absence of overgrazing by deer, grassland is being superceded by dry heath, in which pioneer trees like birch and rowan become established. This is prevented in most of the Highlands today, and on almost all of West Affric the land is kept in a grassland state by the pressure from the deer population.
Near the southwest corner of the exclosure there’s a particular eared willow (Salix aurita) that I’ve been photographing since 1996, about two years after the fence was put up.
The series of images I’ve taken since then provide a simple visual record of the growth of this bush, illustrating the effectiveness of excluding red deer (Cervus elaphus) from the area and how the woodland ecosystem is recovering as a result.
Eared willow supports a large number of invertebrate species, and also grows in wetter soils than birches. Its presence at Coire Ghaidheil means that it is providing a habitat for a range of insects that would not otherwise be able to live in the mostly tree-less landscape in this upper part of the Affric River watershed.
Unlike some of the other willows, eared willow does not grow into a tall tree. In situations like this it will reach a height of 3 metres or so, so this individual may not grow much taller than it is now. However, it should continue to thicken and spread as a large bush, providing a three dimensional habitat of shade and protection for lichens that grow on its stems, plants that thrive underneath it, and insects that feed on it.
At the bottom end of the exclosure is the location of another series of photos I’ve been taking during my recent visits to Coire Ghaidheil, showing the change in vegetation inside and outside the fence. The contrast of mainly grass outside with the heather that is predominating inside provides a strong visual indication of the ecological succession that is taking place there again, for the first time in centuries, if not longer.
Leaving Coire Ghaidheil, we headed further west on the main track that parallels the Affric River. Looking down at one area in particular, where there are a couple of bends in the river, we could see one of the consequences of the loss of the riparian trees that would formerly have lined the river banks here. The upstream-facing bank was being eroded by the flowing water, and large blocks of peat, stranded on a sandbank on the other side, had been carried down from further upstream, where they would have been eroded in a similar fashion.
Continuing westwards, we came to the Carnach Mor exclosure, the most easterly of the areas on West Affric where we planted trees in the 1990s. The exclosure is situated on a south-facing slope, below a boulder-covered part of the hill that gives the area its name – Carnach Mor means ‘great stony place’ in Gaelic. Because of the exposure there, in this otherwise tree-less part of West Affric, the trees struggled to grow initially, and we did some additional planting about 3 years ago, to increase the number that are getting established successfully.
The majority of the trees planted there were broadleaves, but we also put in some Scots pines (Pinus syvlestris). I was pleased to see that most of those were looking healthy, with good growth and new buds just opening out. Some of them were also flowering, with the young female cones visible on the tips of this year’s new growth.
The young trees at Carnach Mor form a green ‘island’ of new forest in the surrounding tree-less landscape and are a good balance to the trees we’ve planted on Forestry Commission Scotland land, on the south side of the river there. Together, they make up some of the ‘building blocks’ of new woodland that in future will hopefully spread out from there, to provide a forest habitat network, stretching from Glen Affric through to the west coast.
As it was getting late in the day, Mick and I headed west again, towards the Alltbeithe Youth Hostel, the most remote hostel in the UK, where we would be staying for the night. The next day, we would be continuing our exploration and surveying of some of the other exclosures we’ve been involved with on West Affric …