Why are we surveying primary and old forest?

FOREST SCIENTISTS Karen Price and Rachel Holt, along with forester Dave Daust, published BC’s Old Growth Forest: A Last Stand for Biodiversity in June 2020. In it they recommended that the Province “Apply an immediate moratorium on harvest of old (and mature) forest in any biogeoclimatic variant with less than 10 percent old forest remaining today. These areas are at overall high risk [for loss of biodiversity]—and in all of these areas, old forest is being harvested today. Opportunities are being lost daily for effective conservation in these zones.”

The biogeoclimatic zone variants they highlighted for an immediate moratorium included CWHxm1, CWHxm2, and CWHdm, which cover most of Quadra, Read, Cortes, Maurelle, East Redonda, West Redonda, Sonora Island, East and West Thurlow Islands and Hardwicke Island. Historically, approximately 70 percent of forests in these biogeoclimatic zone variants would have been greater than 250 years old (Source: BC Cumulative Effects Framework).

Forest scientists have determined that if the percentage of old forest in these zone variants drops below 30 percent, these forests would be subject to a “high” risk of loss of ecological function, biodiversity and resilience. The illustration below showing risk relative to the remaining percentage of old forest is from A Last Stand for Biodiversity.

Risk to ecological function, biodiversity and resilience based on the amount of an ecosystem remaining relative to natural amounts.

Using the Vegetative Resource Inventory (VIR) database created by the BC Ministry of Forests, the percentage of old forest remaining in CWHxm1, CWHxm2, and CWHdm has been estimated by Price, Holt and Daust to be less than 10 percent of total forested area.

This project’s objective regarding old forest is to accurately determine the percentage of remaining old forest and then to lobby government to create conditions that will, as soon as possible, lead to a forest state with a “low” risk of biodiversity loss. That would require at least 70 percent of  the natural level of old forest on the Discovery Islands (source)—which forest scientists estimate was around 70 percent of the total forested area of the island (source)—to be old forest, or 49 percent of total forest cover. We believe this should be the case for each and every island.

Note, too, Price, Holt and Daust’s inclusion of the words “and mature.” Their recommendation would cover significant areas of the Discovery Islands that are currently in the ministry of forests’ timber harvesting land base and are subject to logging. Indeed, some recent logging on the islands has been in areas that these scientists are recommending should be conserved.

In 2019, for example, logging occurred on the north side of Hummingbird Lake on Quadra Island in an area of  250-440-year-old Douglas fir mixed with mature hemlock—an area that had never been logged and is adjacent to Small Inlet Provincial Park and Octopus Islands Provincial Park.

On the Discovery Islands there are still areas of unprotected intact primary forest—by which we mean areas that remain roadless and have never been logged. They may have undergone some natural disturbance, such as fire, within the last century and may contain large, old trees. This project is creating an inventory of  such areas using drone and ground surveys, and the project will work towards a moratorium on logging in these areas.

For our own surveys of old forest we are not using the provincial Vegetative Resource Inventory (VRI) developed by the Ministry of Forests to predict where existing old forest still exists. We have found VRI to be grossly inaccurate: It misses existing old forest and predicts the presence of old forest in places where there is none.

Instead, we are using a combination of drone flights and ground-truthing to determine where old forest still exists.

We are concentrating our primary and old forest survey in the timber harvesting land base to ensure that these areas are left intact, including the younger trees interspersed in these areas of primary old forest. Almost all Crown land on the Discovery Islands is currently within the timber harvesting land base, the main exceptions being provincial parks and ecological reserves.

We are also creating a database of large old trees—based on work done by former Quadra resident Rod Burns—that were left standing after logging.

Please help us map primary forest on all the Discovery Islands. If you know of areas that have never been logged, or have individual large trees that don’t appear on the map below, please contact us with the details.

We are also mapping occurrences of forest that may have been selectively logged (high-graded) in the early years of European settlement and now contain concentrations of old trees that were left uncut. These kind of stands, given the low level of primary old forest that remains on the islands, may be the best candidates for conservation and restoration for the purpose of protecting the biodiversity associated with primary old-growth forests.

Survey of remaining primary and old forest on the Discovery Islands

Our survey of primary and old forest began on Quadra Island in 2018 and continues. To date we have mapped approximately 650 hectares of such forest in 176 areas on Quadra. We are adding mapping for the other islands. In the map below, primary and old forest on Quadra Island is indicated by the areas outlined in yellow. For other islands, polygons outlined in yellow are either old forest or older mature forest. Our summaries for the amount of old forest remaining on each island can be found on this page. For more information about an area, click on it and use the link in the dialogue block that appears. You can pan around the map by clicking on it and dragging. Use the + or - buttons to zoom in or out.

Links to the project’s catalogue of primary and old forest on individual islands:

Quadra Island, Cortes Island, Read Island, Maurelle Island, Sonora Island, West Redonda Island, East Redonda Island, smaller islands

What is old-growth forest? Forester Herb Hammond explains:

Video created by Greencoast Media’s Mark Wunsch for the Discovery Islands Ecosystem Mapping Project