Sitka spruce: a botanical giant, and some giant names in botany

Another Life

Mon, Mar 11, 2013, 06:00

The enrichment of geography that Google now makes possible has had me browsing on the island of Sitka, off the ragged coast of Alaska but quite a bit short of where the Aleutian archipelago reaches out west towards Russia. It has about 8,000 people, plus Sitka port and city, in which the little wooden cathedral of St Michael has a distinctly Chekhovian air. Indeed, the island’s modern name is Baranof, after the governor of Russian America, Alexandr Baranov.

His territory lasted half a century or so before the Russians, hunting the sea otter to near extinction for its fur, sold Alaska to the United States in 1867 for $7.2 million. (All this from Wikipedia, with the fact that the first editor of the Sitka Times , in 1868, was one Barney O’Ragan, who must be somebody’s great-grandfather.)  

Along with the cathedral and some lovely snowy mountains, however, what Google showed me was a forest service shelter, on an inlet at the north end of the island, that “provides local residents as well as tourism kayakers an opportunity to escape coastal rain”. Such uncommon candour brings us nicely to Sitka as home habitat for the spruce tree that has dominated Ireland’s forests for the best part of a century.

The tree grows, in fact, along much of the Pacific coast, from the rain-drenched maze of the Alaskan fringe right down to California, where sea fogs are enough to keep it watered. Sitka just happened to supply an important early specimen, and its botanical dubbing as Picea sitchensis helped to nail the name in place. Given the tree’s runaway success in these islands, it should probably have been named after Archibald Menzies, the Scottish naturalist who discovered it in Puget Sound in 1787.

Fittingly, for a tree that grows to great heights when left alone in nature, some giant names in field botany have figured in the Sitka story. John Muir, for example, the Scottish-born founder of the United States’ Sierra Club and pioneer defender of wilderness, once measured a Sitka at Wrangel, Alaska, with a trunk 150cm in diameter and 764 years old. Another, in Washington, was 55m high at 240 years old.


Dendrological masterwork
I have just learned this, fittingly, from a dendrological masterwork, The Trees of Great Britain and Ireland by Henry John Elwes and Augustine Henry, republished in facsimile to celebrate the 70th anniversary of the Society of Irish Foresters. Only 300 sets of its original eight, large-format volumes emerged, with private funding, between 1906 and 1913, and publishing the elegant and hefty facsimile edition also needed a substantial body of subscribers.

Comparing the two lists of subscribers’ names is to see how the passion for trees has flown on from the hobbyists of the big-house aristocracy, notably of Britain, to the modern growth of native Irish ecology and forestry.

Comparatively few of the books’ hundreds of often beautiful, silvery photographs were taken in Ireland – exotic conifers at Fota, for example, a great arbutus at Killarney, ravishing ashes at Woodstock and Castlewellan – but the interest of the authors’ meticulous, much-travelled study is universal and profound.

Augustine Henry spent much of his life away from Ireland, notably in China, but returning as the first professor of forestry at what is now University College Dublin, he lost no time in urging the case for Sitka spruce as the tree for Ireland’s bogs and “useless” land. He told a government committee in 1907: “We may accept as a general law that all trees native of the Pacific slope of North America from Alaska to Oregon are suitable for planting in Ireland, where they thrive amazingly . . . They find in Ireland a climate exactly like that in which they occur at home.”

In forest plantations, of course, Sitka is not left long enough to develop the enlarged and buttressed base so characteristic of wild trees, with roots spreading widely above ground. The one in my drawing (made from a photograph in volume I) grew in my native Sussex in 1904, when it had reached almost 30m tall, together with a whorl of long, horizontal branches that a crowded plantation would never have indulged. Close planting to produce the minimum of knots in the timber was Augustine Henry’s advice. (“No forestry without a profit,” he urged.)

He and Elwes would have greeted with great anguish the fungal plagues that have since attacked the great trees of these islands: first Dutch elm disease and now the imminent crippling of the ash. Ireland, as he saw, often grew ashes of immense size. “In County Meath, where the soil is remarkably fertile, it has in many parts expelled all the other trees from the hedgerows; and one may drive long distances on the roads between lines of flourishing ash trees, without seeing a single oak or beech.”

How soon will we be left with just the ivy ?


You can find out more about the fascimile of The Trees of Great Britain and Ireland at societyofirishforesters.ie