Old growth temperate rainforests are British Columbia’s most iconic ecosystem; they are what the rest of Canada thinks about when they think of BC’s forests. Unfortunately, this status has not prevented severe over-harvesting and today some of the province’s temperate rainforest ecosystems retain only a very small amount of old growth.

British Columbia’s temperate rainforests are of two basic types: coastal and interior. Coastal temperate rainforests, include coastal Douglas fir and coastal western hemlock forest types. Adjacent mountain hemlock forests share many of the same structural characteristics and threats, but receive much of their annual precipitation as snow and are therefore often considered ‘snow forests’, not rainforests. Coastal temperate rainforests are said to contain more “biomass” (that is, more biological material, dead and living) than any other terrestrial ecosystem in the world. West Vancouver’s Lighthouse Park, MacMillan Provincial Park (Cathedral Grove) and the Carmanah Valley (both on southern Vancouver Island) have good examples of old growth temperate rainforests.

Coastal temperate rainforests stretch all along the BC coast and include forests dominated by cedar, true firs, Douglas fir, hemlock and Sitka spruce. It is in these forests that Canada’s greatest and oldest forest giants can be found: Canada’s largest tree is a massive western red cedar in Pacific Rim National Park, near Cheewhat Lake and the tallest is the ‘Carmanah Giant’, a Sitka spruce 96 meters tall. The oldest tree currently recognized in Canada is a 1300 year old Douglas fir near Squamish, but a yellow cedar felled in the 1980’s was approximately 1700 years old. Larger and older examples may still persist deep in the remaining coastal forests, waiting to be discovered.

The interior temperate rainforests of British Columbia also produce very large trees, and are as well recognized as having the highest diversity of tree species of any forest ecosystem in BC. Found along the lower slopes and in the valley bottoms of the province’s southeast and northwest, they are the most biologically productive forests of the BC interior. Mt Revelstoke National Park and Swan Lake / Kispiox River Provincial Park (northwest of the Hazeltons) are good places to experience old growth interior rainforests.

Temperate rainforests, like tropical ones, have been described as the ‘lungs of the planet’. The huge trees and lush under-story ‘exhale’ huge volumes of oxygen and play an important part in regional hydrological cycles, both by absorbing and storing large amounts of water and by effecting the local climate.

In addition, these highly productive forests absorb and sequester huge amounts of carbon over very long time-scales because the very long intervals between major disturbances. Trees that fall in these forests continue to store carbon for a very long time because the moderate temperatures mean that they are slow to decompose.

Temperate rainforest are also rich in biological diversity. As previously noted, inland temperate rainforests support the highest species of tree diversity of any BC forest type. BC’s temperate rainforests are also national centres of diversity for lichen, mosses, ferns and fungi. Animals associated with old growth coastal temperate rainforests forests include Roosevelt elk, the famous banana slug, pileated wood pecker and several species at risk, including the marbled murrelet, Oregon forest snail and the impressively named dromedary jumping slug. Species associated with old growth inland temperate rainforests include the woodland caribou (a species at risk), marten, fisher and the winter wren.

The major threat to both coastal and interior old growth temperate rainforests is logging, for these forests contain extremely valuable timber resources. Development for residential, commercial and industrial purposes is also a significant threat, particularly for coastal temperate rainforests in southwestern BC.

What can you do to help conserve old growth temperate rainforests? Here are some suggestions:

  • Support the acquisition of lands with remnant old growth stands; this is particularly important on southeast Vancouver Island, where much of the forest land is privately owned;
  • Maintain remnant old growth patches on your own land and consider protecting them with a conservation agreement, or legally with a conservation covenant;
  • Join a conservation organization with a focus on forest issues;
  • Participate in land use planning processes and attend forestry planning reviews; and
  • Make sure that all of your government representatives, local, regional, provincial and federal, know that you value BC’s old growth temperate rainforests and want to see them conserved.

For more information on old growth temperate rainforest and things you can do to help conserve them, we recommend you visit the following sites:

Old Growth Temperate Rainforest