Forest science – Forests of the Future

Explore an ancient mountaintop forest in Sḵwx̱wú7mesh Úxwumixw (Squamish Nation) territories on the Sunshine Coast, British Columbia, Canada.

This undisturbed forest in the Dakota Community Watershed boasts thousand-year-old cedars and 77 registered Sḵwx̱wú7mesh Úxwumixw archaeological sites where yellow cedars were stripped for their fine inner bark, and continued on living.

Xwechtáal (Dennis Joseph) shares stories and knowledge of the area from the Sḵwx̱wú7mesh Úxwumixw, who have lived in the watersheds surrounding Mount Elphinstone for thousands of years.

Registered professional bear biologist Wayne McCrory notes its unusual density of active black bear dens. Coastal black bears rely on old growth trees for winter denning, and McCrory speculates that loss of suitable denning habitat in the surrounding Mount Elphinstone area is leading to unusual accumulations of den sites in higher elevations.

Meanwhile, culturally modified trees from hundreds of years ago are slowly succumbing to heart rot, and creating the next generation of den sites for black bears of the future.

The Dakota Bear Sanctuary was twice proposed for logging by BC government agency BC Timber Sales. It received a one-year deferral by the NDP government in October 2020, days before the provincial election.

Ross Muirhead and Hans Penner of Elphinstone Logging Focus campaigned for years against the Dakota blocks. In summer 2020, they teamed up with The Living Forest Institute to host tours and events in the forest. The Only Animal also organized artists to explore the ancient forest in various artistic mediums.

Gibsons resident Robyn Jacques created a change.org petition that reached 50k signatures at the time of publishing, which she sent to Sunshine Coast-Powell River MLA Nicholas Simons, a cabinet member in the John Horgan NDP government.

UPDATE from the Squamish Nation:

March 1 2021

“The Squamish Nation is pleased to announce that it has entered into an agreement with the Province of British Columbia that protects the Dakota Bowl area on the Sunshine Coast from timber harvesting (logging), now and in the future.

The Nation and the Province are working together on options for land use that recognize the significance of this area, which has been used and occupied by Skwxwú7mesh Úxwumixw since time immemorial. This could include, for example, making Dakota Bowl an Old Growth Management Area, a Wildlife Habitat Area or a Squamish Nation Area of Interest.”

Jens Wieting of Sierra Club BC photographs a giant yellow cedar (Photo by Trent Maynard)

Dr. Nina Hewitt cores a 1m-diameter yellow cedar in Skwxwú7mesh (Squamish) territory on the Sunshine Coast, BC, Canada, aged at approximately 210 years old. (*Photo by Trent Maynard*)

**View Dr. Hewitt’s digital tour of the Dakota Bear Sanctuary**

How to unlock the mysteries of a biological database

An increment borer – basically a corkscrew for trees – is the tool of choice to age living trees without having to cut them down.

Coring a tree removes a tiny strip of the tree’s cross section to reveal annual growth rings hidden inside the trunk.

“It’s about the equivalent for the tree of losing a small branch,” says Dr. Nina Hewitt of UBC Vancouver Department of Geography.

“The tree will immediately put some sap in there,” she says, healing over the point of entry.

Watch below as Dr. Nina Hewitt explains the principles of dendrochronology, the science of dating trees according to annual rings, in an ancient yellow cedar forest, known as the Dakota Bear Sanctuary in Sḵwx̱wú7mesh (Squamish) territory on Mount Elphinstone (Sunshine Coast, BC, Canada).

View Dr. Hewitt’s digital tour of the Dakota Bear Sanctuary

Ancient tree core data has vast applications in science, history and law

A tree’s cross section reveals more than just the tree’s age. It provides information about past climate conditions, including droughts and unseasonable rains, pest epidemics, and even the historical health of salmon runs.

Data stretches back as far as the tree has lived. For the most ancient trees, this biological database can cover a thousands years or more.

If a trees was harvested in the past by indigenous people – for bark strips, pitch pots, or wooden slabs – that tree would continue to live on and heal, and record that harvest in its heartwood database.

A cross section can confirm the date of that harvest, and provide important proof of occupation that has been used to help assert indigenous rights and title over traditional territories.

Cross dating neighbouring trees can improve accuracy and reveal missing or double rings, which can happen in years of extreme seasons or drought.

How to core a tree: Step-by-step instructions from Dr. Nina Hewitt

1) Choose your tree and assemble your tree corer/increment borer. (Shown in the figure is a Haglof increment borer.)
2) Apply bees wax at the tip and along the length of the bit of your tree corer to lubricate it. (The last thing you want, is to get it stuck in the tree!)
3) Choose a good spot close to the base that is easy to access. This can be at chest height, the same height you would measure a tree’s diameter, for easy extraction; or, if capturing the earliest ring, lower down, nearer to ground level.
4) Remove a small bit of the bark if necessary to get a good entry point.
5) Aim for the centre of the tree to improve your chances of a full set of rings. Apply pressure until the corer bites the wood.
6) Holding the ends of the handle firmly, turn in a clockwise direction until you reach the centre. You may wish to use your extractor spoon to gauge your progress towards the centre of the tree.
7) When you think you’ve reached the centre, insert the spoon all the way.
8) Turn the corer back one half-turn in a counter-clockwise direction (see video).
9) Carefully withdraw the spoon to remove the core sample. Place the sample in a specialized straw for safe transport.
9) Remove the coring instrument from the tree as soon as possible, as the tree will tend to exert more pressure over time.
10) Once back in the lab, allow the core to air dry, then mount and sand the sample for inspection. To examine tree rings, dendrochronologists employ measuring stages and microscopes, or more recently, digital imagery and software to identify rings and measure their width. The result is a ring-series that shows the patterns of growth over the tree’s life.
OPTIONAL EXTRA STEPS:
11) Cross-date the tree with some of its neighbours to reveal missing or false rings, which can be caused by atypical climate conditions, like droughts, unseasonably hot/cold temperatures or extreme rainfall. Most tree-ring research involves cross-dating of individual tree cores with regional chronologies.
12) Perform radioisotopic analyses of tree rings to indicate chemical composition and assist in dating.

ADDITIONAL RESOURCES:

Dr. Nina Hewitt’s Coastal Forest Virtual Field Trip

“This lab explores a large remnant of Coastal forest in Pacific Spirit Park, Point Grey, Vancouver, to examine its species composition, structure and dynamics, particularly in relation to human and natural disturbance processes. A set of 360° photos and videos (one in 360°) will be used to demonstrate the local species and landscapes. At the end of the lab, students should have an appreciation for the main species present and the sorts of processes that affect coastal forest dynamics, both natural and human-caused.”