Climate Change and Canada's Forests: From Impacts to Adaptation

Authors
Tim Williamson
Steve Colombo
Peter Duinker
Paul Gray
Ryan Hennessey
Daniel Houle
Mark Johnston
Aynslie Ogden
Dave Spittlehouse
Resource Date:
2009
Page Length
112

Climate change is already affecting Canada’s forests. Current visible effects include changes in the frequency and severity of disturbances (such as fires, drought, severe storms, and damaging insect and disease attacks): other less visible changes such as change in the timing of spring bud burst are also underway. One of the consequences of future climate change will be further increases in the frequency and severity of extreme weather events and disturbances. Changes in productivity, species composition, and age- class distribution are also expected. Moisture and temperature are key factors affecting productivity. Productivity is likely to decrease in areas that are now or will become drier; productivity is expected to increase (at least in the near term) in northern areas that are currently limited by cold temperatures. An important consideration, however, is that genotypes tend to be finely adapted to local climates and potential productivity gains may not be realized if forest managers don’t match genotypes to suitable climates. A higher percentage of the forests will be in younger age classes, and the frequency of early succession species and species adapted to disturbance will increase. Climatically suitable habitats for most species will move northward and will increase in elevation but the actual movement of species will lag behind the rate of movement of climatic niches. Climate change has implications for both current and future timber supply. The net impact of climate change on timber supply will vary from location to location. The recent mountain pine beetle event shows that climate-related factors can have dramatic effects on timber supply in a relatively short time period. Climate change will impact harvest operations. A significant portion of the harvest in Canada occurs in the winter when the ground is frozen. Harvesting on frozen ground allows for access to wetlands, reduces soil disturbance, and decreases costs of delivered wood. The magnitudes of change in climate that will be faced by Canada’s forests and forest management sector and the consequent scale of expected impacts have no historical analogue. Canada’s forest sector will need to adapt and it will need to do so without the benefit of prior experience. Forest managers can expect the unexpected and they can expect that change will be ongoing and unrelenting. Some general recommendations for beginning to address climate change in Canada’s forest sector include enhancing the capacity to undertake integrated assessment of vulnerabilities to climate change at various scales; increasing resources to monitor the impacts of climate change; increasing resources for impacts and adaptation science; reviewing forest policies, forest planning, forest management approaches, and institutions to assess our ability to achieve social objectives under climate change; embedding principles of risk management and adaptive management into forest management; and maintaining or improving the capacity for communicating, networking, and information sharing with the Canadian public and within the forest sector.