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Garry oak areas are some of Canada’s most endangered ecosystems. Once common in coastal areas of southwest British Columbia, less than 5% of these ecosystems remain in a near-natural condition. Garry oak areas (or ecosystems) are more than just trees. They include woodlands with Garry oak, arbutus, or Douglas-fir trees, often combined with rock outcrops, natural wildflower and grassy meadows, coastal bluffs or seasonal pools.
Garry oak areas are the richest landbased ecosystems in southwest British Columbia, providing habitat for more than 100 species of birds, 7 amphibian species, 33 mammal species, more than 800 invertebrate species, and about 700 plant species.
Garry oak ecosystems are found on southeast Vancouver Island, on the Gulf Islands, and in two small areas in the Lower Fraser Valley. They occur nowhere else in Canada. These ecosystems are also found in Washington, Oregon and California (where the trees are known as Oregon white oaks). In Canada, the Garry oaks are at the northern extent of their range.
Land development, invasion by exotic species, fire suppression, trampling by people and their pets, and poor management practices all contribute to the loss of Garry oak areas. More of the remaining areas are likely to be lost in the next decade. Fire suppression allows Douglas-fir and other trees and shrubs to invade Garry oak areas, shading out and eventually replacing the trees and wildflowers.
As the ecosystems disappear, so do the species they support. There are more than 100 species at risk in Garry oak areas — species that are identified by the federal or provincial governments as ‘at risk’ of becoming extinct.
Unfortunately, protection measures and conservation strategies often focus only on the oak trees. While protecting Garry oak trees provides important habitat for many species, it is even better to protect whole ecosystems, including the understorey shrubs, ground cover and wildflowers, and to avoid small ‘islands’ of native trees surrounded by non-native landscaping or pavement.
Protecting Garry oak areas is a kind of insurance for the future — for people as well as for the plants and animals that these ecosystems support. As the song says, “you don’t know what you’ve got ‘til it’s gone.”