Coastal Douglas-fir Ecosystems

The following information is sourced from the documents listed under the “Learn More” section below.

The Coastal Douglas-fir (CDF) zone is the smallest and rarest ecological zone in British Columbia. Within Canada, it is found in Halfmoon Bay on the Sunshine Coast, a narrow band along southeast Vancouver Island, Qathet, the Gulf Islands, Texada and Lasqueti Islands, and a narrow fringe of the Lower Mainland. Its climate is mild and dry by Canadian standards, with warm summers and wet winters, creating conditions found nowhere else in the country. These conditions support a mix of forests, meadows, and wetlands that contain the highest plant diversity in BC, and habitat for many species found nowhere else in Canada.

The zone is also one of the most altered by human activity. Much of its land is privately owned, and it overlaps with some of BC’s fastest-growing urban and agricultural areas. Settlement, logging, farming, and development have removed almost all old-growth forest—none remains on the Sunshine Coast and less than 1% in BC. The Province of BC aims to maintain at least 9% of these forests as old growth.

The Coastal Douglas-fir zone is considered a conservation priority because it is so small, biologically rich, and heavily impacted. Protecting it means safeguarding unique biodiversity, cultural heritage, and the natural systems that support clean water, carbon storage, and climate resilience.

Invasive Species

Coastal Douglas-fir forests are highly vulnerable to invasive species due to their small size, fragmentation, and proximity to urban areas. Invasive plants such as English ivy, English holly, Himalayan blackberry, knotweeds, giant hogweed, poison hemlock, and Canada thistle outcompete native vegetation, smother or kill trees, and disrupt ecosystem processes. Their spread reduces biodiversity, degrades habitat quality, and undermines the resilience of this already rare and at-risk ecosystem.


Commonly Asked Questions

Where is the Coastal Douglas-fir zone located?

In BC, it is found in Halfmoon Bay on the Sunshine Coast, Thormanby and Lasqueti islands, southeast Vancouver Island from Victoria to Comox, most Gulf Islands, and a narrow fringe of the Lower Mainland. It covers about 0.3 % of British Columbia’s land area.

Why is it called “Coastal Douglas-fir” if other trees grow there too?

Douglas-fir is the most common and ecologically dominant tree in this zone, but it coexists with Arbutus, Western Red Cedar, Grand Fir, Garry Oak, Bigleaf Maple, and other species. Salal, Oregon-grape and Ocean Spray are also dominant shrubs.

What makes the CDF zone unique and different from other BC ecosystems?

Confined to a narrow coastal strip, it has evolved in the mildest climate in Canada with dry summers and wet winters. It supports the highest plant diversity in BC, and the greatest number of species at risk in the province. The Douglas-fir ecosystems of the Salish Sea differ from those in other areas; with their unique geology, they evolved within protected waters and a dry, rainshadow basin. Its importance is recognized by federal and provincial governments, and is included in Canada’s twelve Priority Places (Southwest British Columbia) .

How much of the original forest is left?

Provincially less than 1% of old-growth Coastal Douglas-fir forest remains. No old growth (over 250 years) remains on the Sunshine Coast, much of what’s left is second-growth with altered species composition and structure.

Which species or habitats are unique to it?

Habitats include Douglas-fir forests, wetlands, and rocky outcrops. There are 24 globally imperiled species, 282 provincially listed species at risk, along with 45 ecological communities at risk.

Why is it considered endangered?

It is the smallest biogeoclimatic zone in BC, heavily developed for housing, farming, and industry. Most of its 45 ecological communities are classified as endangered due to habitat loss, fragmentation, and invasive species. Due to its desirable coastal location it overlaps with BC’s most densely populated areas, making it both highly accessible and highly threatened.

Who owns most of the land in the CDF zone?

Provincially 80% is privately owned, unlike most BC forests which are public Crown land.

How does climate change affect the CDF zone?

Hotter, drier summers and more extreme weather increase drought stress, wildfire risk, and competition from invasive species.

What are the main threats besides logging and development?

Invasive plants, fire suppression, overgrazing by deer, climate change, recreational overuse, and hydrological changes from roads and construction.

What can private landowners do to help protect it?

Maintain natural vegetation, control invasive species, keep animals from roaming, avoid fragmenting habitats, and consider a covenant or land donation.

How much of it is currently protected?

Provincially about 11 % of the zone is in parks, protected areas, or under formal conservation agreements.

Learn more