On a cloudy day up Blackcomb Mountain, the Ascent Trail became more than just a hike, it became an outdoor classroom for the first event in our three-part educational programming series, Protecting Priority Habitats campaign. Led by conservation biologist Bob Brett, whose work spans ecosystem classification, tree-ring histories, and wildlife-focused forest management, explored how ancient ecosystems of living, dying, and dead trees provide essential habitats from cavity-nesting birds to larger wildlife, and why we should protect what remains.
Our general and Youth Engagement committee participants hiking up the Ascent Trail.
Bob began by teaching us how to read the forest’s history. Much of Whistler’s lower slopes are “second-growth”, recognized by young stands, less than 90 years old, that regenerated after logging some 70 years ago. These areas are often crowded and uniform: trees of the same age and height, little sunlight reaching the floor, and old stumps scattered from past clearcuts. Compared to places like Vancouver Island, logging happens even faster (every 40 to 50 years) creating simplified third-growth forests more vulnerable to pests and fire. Yet even these young forests have value. With time and protection, they are the foundation to developing into complex habitats for wildlife and vital carbon stores in the future.
By contrast, old and ancient forests feel different the moment you step into them. In Whistler, “old” means trees over 250 years old; “ancient” can be 400 years or more. These stands may be common in Whistler but rare, both in B.C. and globally. They are open and spacious, with wide-spaced trunks, a rich understory, and logs and provide essential habitat for wildlife. Beneath the soil, vast mycorrhizal networks, hidden webs connecting trees and fungi, reach their peak, supporting life above and below ground. The older the trees, the more intricate and connected these networks become, having had centuries to develop. Carbon storage is also at its highest, making these forests powerful carbon sinks in the fight against climate change thus when old growth forests are logged, we not only remove the canopy but also release carbon stored in soils back into the atmosphere. True old growth can’t be planted or rushed, it develops complexity over centuries.
We stopped at a forest thinning demonstration area, where trees had been selectively removed 15 years ago. More sunlight now filters to the forest floor, allowing blueberries, mosses, and young understory plants to thrive. Bob explained the difference between traditional logging, which removes the largest, most valuable trees, and well-done thinning, which removes smaller trees to reduce fire risk and accelerate forest succession. By opening the canopy, this brings light to the forest floor, and creates richer wildlife habitat. Even the current spruce budworm outbreak (seen by the alarming patches of red needles on Douglas-firs) is part of the natural cycle. In landscapes dominated by dense young stands, these insects do some of the thinning work that fire once did, creating openings for new growth without the cost or scars of logging roads.
The cones of common tree species in Whistler. From left to right: western red cedar, Douglas-fir, western hemlock, yellow cedar
Along the way, we identified Douglas fir, western redcedar, and western hemlock trees by their bark, needles, and cones. Cottonwoods and “danger trees” are essential for wildlife despite being seen as pests or hazards. Cottonwoods are fire-resistant from their wood and bark hold a high amount of water, which helps them withstand and slow the spread of flames. Wildlife such as coastal tree frogs, pileated woodpeckers, goshawks depend on old growth trees trunks for food and nesting. By the time we reached higher elevations, the forest had begun to change, trees grew shorter, species flipped to their alpine versions, and the air felt cooler. This was a living demonstration of how climate, elevation, and time shape these ecosystems.
The hike was organized as part of the implementation phase for the Priority Habitat Framework. Through the RMOW’s online webmap, residents can explore more than 25 ecosystem and habitat layers, revealing the forests most critical for wildlife and climate resilience. Key areas like Jane Lakes, 21-Mile Creek, Rainbow Trail, and parts of Whistler Blackcomb still hold unlogged, old, or interior forests worth protecting. By engaging with these maps, volunteering, or advocating for conservation, we can all help safeguard these irreplaceable ecosystems.
As Bob put it, intact forests are a legacy. Walking among old growths on the Ascent Trail was more than just a hike. It was a lesson in reading the forest’s history, understanding the impacts of human activity, and seeing what’s at stake. Protecting our remaining old and ancient stands and allowing today’s second-growth forests to mature provides future generations the gift of restored ecosystems, resilient wildlife populations, and powerful carbon sinks. You can’t plant an ancient forest, but you can protect one and doing so may be one of the most effective climate actions we have.
We would like to thank Armchair Books and Picnic Whistler & Deli in providing the prizes for this event.
Missed the hike? Don’t worry we have two more programs coming up!
Maintaining Healthy Waters: Water Health Seminar
Featured Presenters:
- Dr. Peter Ross – Senior Scientist with the Raincoast Conservation Foundation and Director of the Healthy Waters program. Dr. Ross is a marine pollution expert whose work focuses on water quality and ecosystem health across B.C. and beyond.
- Lynn Kriwoken – President of the Whistler Lakes Conservation Foundation (WLCF). Lynn brings a wealth of experience in water policy and stewardship, and leads local conservation projects that protects Whistler’s lakes and waterways.
- Bob Brett – A Whistler-based forest ecologist, a professional biologist, and the founder of the Whistler Biodiversity Project and Whistler Naturalists. He specializes in ecosystem classification, forest ecology, and conservation biology, and is involved in research on ancient forests, invasive species and wildlife habitat. He is the lead researcher on the Priority Habitat Framework for the RMOW (Resort Municipality of Whistler) and for the RMOW’s Ecosystems Monitoring Program.
Event Date: October 25 , 2025
Event Time: 12:30pm – 3pm
Event Meeting Location: Myrtle Philip Community School, Millar Room
Register Here: Eventbrite
Protecting Wildlife: Grizzlies, Cougars & Wolves Workshop
This workshop led by Michael Allen is an opportunity to learn about the animals’ behaviours, habitat needs, and challenges (such as forest fires and other climate extremes) these predators and keystone species face. Michael’s extensive fieldwork and decades of research in the Sea to Sky corridor will provide a unique, science-based perspective on the vital role these animals play in maintaining healthy ecosystems.
Event Date: Thursday, November 6, 2025
Event Time: 6pm – 7:30pm
Event Meeting Location: Whistler Public Library
Register Here: Eventbrite
These events are all free, with a suggested $5 donation
