In many areas of North America, the end-of-summer is marked by the exuberant colours of autumn foliage. Fall colours are the result of plant senescence, the gradual deterioration and death of a plant or part of a plant (e.g. leaves of deciduous trees and shrubs) following the summer growing season. During senescence, the chlorophyll of the leaves disintegrates and the green colours diminish. However other photosynthetic pigments – for example the yellow-orange carotenes and xanthophylls - do not break down as quickly as the chlorophylls. Their colours persist for a while longer, and are revealed as the chlorophyll degrades. Also, some pigments in the leaves are produced as by-products of plant senescence, and these contribute reds to the autumn display. Day length, temperature, and light intensity are among the environmental factors that influence the onset of leaf senescence and the spectacular colours seen in the autumn woodlands of North America.

There is only one tree on Sable Island – a Scots Pine. This lone pine, located near a freshwater pond not far from the Station, is over 40 years old, but less than 100 cm in height. And being a pine, it is nondeciduous – its leaves do not colour-up and drop to the ground every autumn. However, a landscape does not need trees to glow with fall colours.

During September and October the vegetated terrain of Sable Island becomes a tapestry of pale yellow, tan, amber, buffy, orange and sienna, with the bright greens of juniper and crowberry woven throughout. The island’s fall colours are often enhanced by the winds of tropical storms, and sometimes hurricanes. During such storms, foliage on the windward sides of shrubs is sandblasted and browned as high winds sweep across the island carrying sand from the beach and inland blowouts. When the storms pass, the landscape is richer than ever in complexion and detail. Late-season flowers such as goldenrod and aster, the bright reds of berries, the soft rufous and brown tones of horses, the blues and greys of big clouds, and the wine-coloured beaches, make for a season energized with colour and pattern.

The solitary tree of Sable Island.

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