A Global Heritage in Peril
BC coastal old growth forest. Photo credit: Joe Foy
When most people think about rainforests, they imagine steamy hot tropical jungles of South and Central America, Asia and Africa. But rainforests—lush forests that grow where precipitation is at least 2000 mm (over 6 feet) and is spread out relatively evenly over most of the year, are also found in temperate regions of the world. Temperate rainforests grow along a thin band of land where moist ocean air collides with coastal mountains.
Temperate rainforest ecosystems occupy only a small part of our planet. It is estimated that five hundred years ago, there were 30,000,000 hectares (ha) of temperate rainforest growing on Earth – about one-fortieth the extent of tropical rainforests. Areas with temperate rainforests include western North America, Chile, New Zealand, Australia, Japan and Norway.
The maritime temperate climate, with its moist summers and mild winters, is very favourable to forest growth. Because of the infrequency of fires and other large-scale natural catastrophes, the temperate rainforests are characterized by very old and very tall and large trees. These forests have high biodiversity in comparison to other temperate ecosystems, although much less than that found in tropical rainforests which never experience freezing or frost. However, the living biomass accumulation of the temperate rainforests is more that three times as much as in the faster growing and faster decaying tropical rainforests. The temperate rainforests on North America’s west coast have the largest accumulations of living organic material per hectare of any ecosystem on Earth!
Although everyone is aware of the current, devastatingly rapid loss of the world’s tropical rainforests (estimated to be as much as 50 ha per minute), temperate rainforests have been under human pressure for a much longer time and have suffered proportionately greater loss. The original temperate rainforests of Ireland, Scotland, France, Yugoslavia, and Turkey are all gone. In western North America—home to over 50 percent of the world’s original temperate rainforests—over 60 percent of the original Canadian temperate rainforest, and 90 percent of the American temperate rainforest have been destroyed.
The ancient temperate rainforest of BC is without a doubt one of the natural wonders of the world. In Carmanah Valley, on Vancouver Island, grows the tallest known living tree in Canada—a 95 meter high Sitka spruce. In these forests, trees over 1,000 years of age are common and the oldest known and recorded are nearly 1700 years old. Few doubt that there are trees over 2,000 years old growing somewhere in one of BC’s remaining wild, unlogged watersheds.
As scientists learn more about the ancient old growth temperate rainforest along the coast of BC, they are finding more and more “old growth dependent” species—plants and animals that need an intact old growth forest in order to survive.
Only one third of BC’s primary temperate watersheds are still wild. We have a responsibility to all inhabitants of this planet, present and future, to set aside self-sustaining areas of temperate rainforest as wilderness, forever.
