Tasmania and Ceylon shortly before 1932. Nisbet noted that firmly-rooted white spruce served very well to stabilize windswept edges of woods in Germany. In a narrow belt of mixed Norway and white spruces over an extremely exposed hilltop crest at high elevation in northern England, the Norway spruce were “completely dwarfed” whereas the white spruce had reached heights of between 3 and 4.3 m. The age of the belt was not recorded, but adjoining 66-year-old stands may have been of the same vintage. White spruce has also been used as a minor plantation species in England and Scotland. In Scotland, at Corrour, Inverness-shire, Sir John Stirling Maxwell in 1907 began using white spruce in his pioneering plantations at high elevations on deep peat. However, plantations in Britain have generally been unsatisfactory, mainly because of damage by spring frosts after mild weather had induced flushing earlier in the season. However, the species is held in high regard in the Belgian peat region, where it grows better than do the other spruces. Ecology White spruce is a climax canopy tree in the boreal forests of Canada and Alaska. It generally occurs on well-drained soils in alluvial and riparian zones, although it also occurs in soils of glacial and lacustrine origin. The understory is dominated by feather mosses (Hylocomium splendens, Pleurozium schreberi, Ptilium crista-castrensis) and fork mosses, and occasionally peat moss. In the far north, the total depth of the moss and underlying humus is normally between , although it tends to be shallower when hardwoods are present in the stand. White spruce grows in soils with pH values of 4.7–7.0, although they have been found in soils as acidic as 4.0 in subalpine fir forests in the Northwest Territories. A presence of calcium in the soil is common to white spruce found in northern New York. White spruce most commonly grows in the soil orders of Alfisols and Inceptisols. Soil properties such as fertility, temperature, and structural stability are partial determinants of the ability of white spruce to grow in the extreme northern latitudes. In the northern limits of its range, white spruce is the climax species along with black spruce; birch and aspen are the early succession species. Wildfires typically occur every 60 to 200 years, although they have been known to occur as infrequently as every 300 years. White spruce will grow in USDA Growing Zones 3–7, but is not