British Columbia's forests are facing a formidable challenge as climate change threatens to alter their ecosystems dramatically. In the coming decades, the province is expected to experience more frequent and severe summer conditions. This environmental shift puts pressure on the region's big trees, typically aged between 100 and 150 years, which are struggling to adapt to rapid climate changes. In response, researchers and forestry experts are developing innovative tools and strategies to aid these forests in their transition to a changing climate.
Suzanne Simard from the University of British Columbia has played a pivotal role in crafting an online seed-selection tool. This tool assists planners in sourcing seeds suitable for both current conditions and projected climates of the 2050s and 2080s. As climate change accelerates, trees find it increasingly difficult to disperse their seeds, with the majority falling within a few hundred meters of the parent tree. The tool aims to address this challenge by facilitating the selection of seeds that can thrive in evolving conditions.
“It’s got to be done slowly and carefully,” – Simard
In areas prone to drought and frost, retaining 30 to 60% of the old canopy is crucial for seedling recovery. Without this protective canopy, clearcut forests can become excessively dry and hot during summers and lack frost protection in winters. Douglas fir seedlings, in particular, have a better chance of surviving assisted migration when planted in intact ecosystems that provide protection, nutrients, water, and compatible neighboring species.
“It’s not like a mass migration of trees.” – Simard
Climate models predict that B.C.'s tree species could shift northward by up to 100 kilometers per decade. This movement might lead to boreal and sub-boreal ecosystems being largely replaced by hemlock, ponderosa pine, and Douglas fir. The findings suggest that strategic seed selection and planting in colder climates can succeed if paired with forest management practices that maintain ecosystem integrity.
“Those migrants need a lovely place to land. They need protection from the older trees,” – Hamann
The Canada-wide "Diverse" project collaborates with the logging industry and provincial governments to test new forestry approaches under climate change. Early results indicate that while Douglas fir may still have a future by the 2080s, seeds will increasingly need to be sourced from forests further south, such as Idaho or Montana. In more productive, wetter regions, even retaining 30% of old canopies has proven beneficial for seedlings.
“We expected them to have a protective effect, and we found out that they do.” – Hamann
The recent heat dome of 2021 has already impacted tree productivity in areas like Nelson, where cedar and Douglas fir trees show signs of reduced growth. Such events underscore the urgency of adapting forestry practices to changing climatic conditions. Despite these challenges, there is optimism about the potential for assisted migration to support forest resilience.
“Douglas fir does really well when there’s a good snowpack,” – Simard
“There is a good rationale for assisted migration,” – Hamann
As fires become more frequent, selecting appropriate species for regeneration is critical. This approach ensures that new plantings align with the ecosystem's evolving needs.
“You have a forest that burns down. Now you have to pick a species that fits that ecosystem.” – Hamann
