A fruitless petition in verse
In the late summer of 1787, Robert Burns set out on a tour of the Scottish Highlands. He had been invited to stay at Blair Castle, the family seat of John Murray, fourth Duke of Atholl; his lordship advised the poet to be sure to make the detour to view a local beauty spot, the necklace of falls known as Bruar Water. Burns found Atholl picturesque and beautiful ‘‘but much impaired by the want of trees and shrubs’’. After he had negotiated the steep track up and down from Bruar Water he lamented in his journal that there being ‘‘not a bush to be seen about them [marred] much their effect’’.
He was not the first to be so disappointed. William Gilpin, an apostle of the Picturesque movement which foreshadowed Romanticism in Britain, had struggled up to the falls 10 years before, only to remark that the cascades were ‘‘scarce worth so long and perpendicular a walk. One of them indeed is a grand fall, but… so naked in its accompaniments… that upon the whole it is of little value.’’
The publication of Poems Chiefly in the Scottish Dialect in April of 1787 had brought Burns great celebrity; this he put to work for Scottish nature by writing a poem in the persona of Bruar Water itself, begging the duke to revegetate the treeless hillsides.
It is possibly the first time that any poet ventriloquised for inanimate nature. Of all of Burns’s poems The Humble Petition of Bruar Water is possibly the least known. Let lofty firs, and ashes cool, My lowly banks o’erspread, And view, deep-bending in the pool, Their shadow’s wat’ry bed: Let fragrant birks, in woodbines drest, My craggy cliffs adorn; And, for the little songster’s nest, The close embow’ring thorn. Though both the duke’s and the poet’s posterity may wish to believe that his lordship leapt to the task, it took him a good 10 years to begin revegetating, by which time Burns was dead. The duke ignored Burns’s good advice, planting 120,000 Scots pine and larch.
The choice of larch was possibly ill-advised; Larix decidua is native to central Europe where it tends to grow on well-drained hillsides in isolated stands; in Scotland it was growing well outside its range. Burns was a countryman, and his advice is to grow the native woodland mix, fir, ash and birch, with hawthorn and dog rose to provide habitat. The sober lav’rock, warbling wild, Shall to the skies aspire; The gowdspink, Music’s gayest child, Shall sweetly join the choir; The blackbird strong, the lintwhite clear, The mavis mild and mellow; The robin pensive Autumn cheer, In all her locks of yellow. “Laverock” is the Scots name for the lark, “gowdspink” for the goldfinch, “lintwhite” for the linnet, “mavis” for the songthrush. The word “biodiversity” had not been coined in Burns’s time, but he certainly knew what it was.
Five thousand years ago Scotland was covered with a mosaic of woodland, pineforest, heath, scrub and bog; its deforestation was largely a consequence of human settlement, clearing and grazing. Though pockets of woodland had been preserved to provide fuel and timber, by the end of the 18th century even these were considered surplus to requirements and no longer protected from the marauding deer bred for hunting on the larger estates.
The Duke of Atholl’s reafforestation, which eventually amounted to 15million trees and brought him the sobriquet of ‘‘Planter John’’, did not start a fashion. During the Second World War, many of the Duke’s plantings were cleared, to be replaced with a mixture of hybrid larches, Scots pine, fir and spruce while native broadleaved species, rowans, willows, aspen and birches were left to seed themselves along the braes.
We can only wonder now whether it was the close planting of larches that has led to the development of the disease that is now killing larches in Britain. The disease, caused by an organism called Phytophthora ramorum, is more rampant on the wetter, western side of the country, which seems to suggest that cultural conditions have something to do with its prevalence. In Oregon and California P. ramorum is killing oak trees; in Britain oak trees in the wild are hardly affected. The explanation is that the American form is a different mating type. The usual assumption, that a fungal pathogen like phytophthora is transmitted by contact, seems ill-founded. Like many other pathogens affecting trees, the lethal forms of phytophthora seem to develop within intensive plantings. Chalara fraxinea, the organism now killing ash trees, has, as its name suggests, always been associated with ash trees. It became a lethal pathogen within European plantations, possibly within the nursery industry.
It looks very much as if diseases like P. ramorum are part of the sylvan environment; trees may suffer from them occasionally and usually recover, unless the growing conditions are such as to foster an enormous increase in the prevalence of such infections, whereupon they turn lethal.
The solution to loss of habitat is, as Burns understood, not to plant huge numbers of a very few species, some of them exotic, all of them probably much too close together, but to restore the endemic woodland mix. Planting trees is not enough; woodland requires management at least until it has reached maturity, in some cases forever.
As those good people now buying up woodland are realising, in the 21st century trees cannot be left to take care of themselves.