There's been a lot of talk about major infrastructure projects in Canada lately, with the federal government planning to fast-track resource development across the country.
This push isn't surprising. In 2024, the natural resources sector accounted for 16 per cent of Canada's GDP and provided 1.8 million jobs .
Yet these economic benefits result in trade-offs for the environment, with many consequences still unclear. Before accelerating development with less environmental oversight, these unknowns need to be considered.
Examples of unintended environmental consequences aren't hard to find across Canada. If someone told you about a high-density network of corridors, often spaced less than 100 metres apart, you might picture city roads or an urban park trail system.
In fact, such a network of linear clearings , also called seismic lines, can be found across Canada's boreal forest. There are an estimated over 1.8 million kilometres of such clearings in Alberta alone.
They were, and continue to be, created for geophysical exploration, allowing personnel and equipment to move across the landscape and map underground resources like oil and gas. In Alberta, early records of this type of exploration date from the late 1920s, with activity greatly expanding from the 1960s onwards.
As these exploration programs expanded, governments didn't require companies to return the land to how it was before . The assumption was that trees would simply regrow on the narrow clearings, returning forest cover to the landscape. However, many seismic lines have remained without forest cover for decades , particularly when they cross forested wetlands.
While improvements in geophysical technology and a recognition of the environmental consequences have led to lower-impact methods, this legacy of activity remains as a grid that scars forests.
Fragmented forests
Seismic lines fragment forests and alter their ability to act as habitats and provide climate change mitigation benefits. Forest fragmentation shifts how animals use the region, and has been linked to sharp declines in woodland caribou .
These open corridors allow predators to move faster and see farther, resulting in more caribou hunted. Meanwhile, they make it easier for other herbivores, like deer and moose, to access the otherwise dense forest, increasing competition for food.
Seismic lines also affect the ability of peatlands to support climate regulation. Peatlands store vast amounts of carbon . The remains of plants deposited in peatland soil are protected from decomposition by wet, cool and acidic conditions.
These wet conditions also enable the production of the greenhouse gas methane. But much of the methane produced is consumed by microbes living in the upper soil layers and is never released to the atmosphere.
The methane-consuming microbes require aerated conditions, which are maintained due to a fluffy layer of moss at the surface that drains easily. Under these undisturbed conditions, carbon storage in the peatland more than offsets methane emissions, so that peatlands provide a net climate benefit.
Disturbance of the soil in peatlands by heavy equipment during geophysical surveys compresses this surface layer, leading to wetter conditions. This is one of the reasons that trees are slow to return, and it also results in higher methane emissions . This can shift the greenhouse gas balance in peatlands, causing them to contribute to climate warming.
An understanding of these unanticipated effects has only been possible due to decades of research in the boreal forest . That knowledge is now being used to develop restoration programs aimed at returning forest cover to support recovery of woodland caribou populations.
These restoration programs are aimed at providing environmental benefits, but they also come with unplanned financial costs. This highlights the need for environmental oversight that prevents such problems in the first place and provides long-term cost savings .
Effects beyond seismic lines
The story of seismic lines is not unique. Unanticipated impacts may be more the rule than the exception. For example, mining produces a range of waste products that impact water quality .
Resource access roads act as dams in wetlands , altering water flow, causing flooding and killing trees upstream.
Human development in wildlands can increase wildfire risk , leading to greater burned areas. Regulations are in place and need to be continually reviewed and updated to ensure that environmental and human health and well-being are protected as projects proceed.
Environmental impacts are assessed using our best available knowledge before projects are approved.
However, what remains hard to evaluate is the response to the combined impact of all activities on the landscape. These cumulative effects can be difficult to predict. Disturbances can interact in unexpected ways, sometimes leading to greater impact than anticipated based on the sum of the areas affected.
Understanding how to assess and manage cumulative effects is an ongoing area of research. As our knowledge grows, these cumulative impacts need to be better integrated into decision-making about future development.
Canada's boreal forest remains one of the most intact on the planet. Protecting it comes with challenges, however, and it would be even harder to restore once the forest is lost. As major projects continue to be proposed and approved, it will be important to move forward with the goal to protect the land upon which Canada is built.
Maria Strack receives funding from Natural Sciences and Engineering Research Council of Canada, Environment and Climate Change Canada, Parks Canada, Government of Alberta, the Canadian Sphagnum Peat Moss Association, Ducks Unlimited Canada, Imperial Oil Ltd., Alberta Pacific Forest Industries Inc., Cenovus Energy, Canadian Natural Resources Limited, ConocoPhillips Canada, Natural Resources Canada, and the Alberta Biodiversity Monitoring Institute. As part of the Can-Peat project, Maria Strack collaborates with a network of partners across Canada including provincial, territorial and municipal governments, Indigenous organizations and private and not-for-profit groups.
