A new frontier: The wilderness above our heads

THE Crannell Giant, which had lived for 3,000 years near the Little River in Humboldt County, California, was felled by loggers in 1926. It contained about 70,000 cubic feet of wood, making it the biggest single organism ever recorded.

The largest tree alive today, the General Sherman, has about 50,000 cubic feet of wood. Its trunk is 27 feet thick at breast height. If it were cut into inch-thick planks a foot wide and they were laid end to end, the line would stretch for 125 miles. So claims Richard Preston in a new book. Subtitled “what if the last wilderness is above our heads”, The Wild Trees is a celebration of the world’s biggest trees and the dozen or so pioneering naturalists and tree-huggers who climb and study them. Described as “narrative non-fiction”, it reads like a novel, the adventures of its characters being interspersed with observations on the trees.

Some of Canada’s Douglas firs were taller than any tree alive today but all of the really big ones have been destroyed by loggers. Some of Australia’s eucalyptus regnans are giants but the blue whales of the plant kingdom are the redwoods which live along the west coast of the United States. Members of the cypress family, they first appeared about 280 million years ago, long before dinosaurs roamed the Earth. There are two species. The sequoia sempervirens, known as the California redwood, is the world’s bulkiest and heaviest tree. The sequoia giganteum, or coast redwood, is lighter but higher. Mature specimens, over 30 storeys high, are much taller than Dublin’s Millennium Spire. Some redwoods alive today may be 3,000 years old. Their exact ages can’t be determined; the inner core of an old tree dies, becoming hollow and tree-ring counting is not possible.