Heather or ling Calluna vulgaris is one of the most successful plants in the Assynt landscape, recorded in the Flora of Assynt (2002) from 159/164 tetrads surveyed for that work. It comes into its own in August, when the flowers colour large parts of the landscape a characteristic pale purple.
It is so abundant that we perhaps tend to overlook important aspects of its biology and its role in local ecosystems. This was brought home to me recently when, after a very wet spring, I finally got to mow the ‘lawn’ in the back of my garden at Nedd (NC137319), from which there is a fine view up and across Loch Nedd.
In the middle of a grassy/mossy sward there is a rocky island bed, into which some 25 years ago a plant of heather seeded itself. Over the intervening period this grew into a fine upstanding clump 1m high and 3m in diameter, but latterly it has begun to show its age. Central stems have sprawled outwards and are beginning to die off, their bases becoming heavily encrusted with lungwort lichen Lobaria pulmonariaas light penetrates the interior of the clump. However, there is still life in the peripheral stems, which may have re-rooted themselves. Although it is not a sight to gladden the heart of a keen gardener, I have left the bush alone, to see if it would cast any light on the question of what age a single heather plant can attain without interference. The answer is, obviously, at least 25 years and possibly many more.
This sprawling clump has, in its old age, provided a nursery bed for the germination of tree seeds from the surrounding garden. It now shelters flourishing saplings of hazel, downy birch, rowan and eared willow, a couple of plants of bell heather Erica cinerea, and a variety of herbaceous perennials such as common dog-violet Viola riviniana.
These saplings led me to ponder the view from my garden across Loch Nedd, where heather-dominated rocky slopes come right down to the edge of the sea. Trees are colonising sheltered gulleys in these slopes, spreading out from established woodland slightly further inland, and I have been watching their gradual advance since we moved into our house in 1991. Their spring and autumn colours enable me to confidently identify the few species involved, albeit across 200m of sea. Along the upper edge of the rocky tide-line are isolated groups of aspen, there are scattered rowans, but the dominant species, as throughout Assynt, is downy birch. This last is the species that is pioneering the slow conversion of much of the area back to native deciduous woodland, through the dense protective cover of the heather.
Elsewhere in Assynt, this natural process is still being severely constrained by heavy grazing and browsing, mainly, nowadays, by red deer, although there were many sheep on the area in the past. Curiously, the deer seem to avoid these exposed seaward slopes; I have only ever seen one through my binoculars. The area has also, happily, escaped the disastrous effects of the muirburn, accidental or deliberate, which has, over the years, reduced the vegetation of large parts of the local landscape to ashes, and continues to do so in places.