Forest Land

Understanding Forest Land emissions

Understanding the "Forest Land" sector in Canada’s National Inventory Report (NIR) involves a complex accounting system that distinguishes between what humans control (harvesting) and what nature controls (wildfires). In the context of the Intergovernmental Panel on Climate Change (IPCC), "Forest Land" falls under the broader Land Use, Land-Use Change, and Forestry (LULUCF) sector.

Firstly, to understand Canada's emissions in this sector, it's important to distinguish two types of forest:

  • Managed Forests: These are forests under direct human influence, including lands managed for timber harvesting, fire protection, or conservation. This covers roughly 226 million hectares (about 65% of Canada's total forest area).
  • Unmanaged Forests: Remote northern forests not subject to active human stewardship are generally excluded from the inventory until human activity (like a new road or mine) expands into them.
Canada only reports emissions and removals from "Managed Forests."

Factors

  • Harvest
  • Natural Disturbances
  • Growth
  • Land use Conversion (e.g. deforestation)

Historically, Canada's forests were a large sink. However, due to aging forests, higher harvest rates in the past, and increasing natural disturbances (fires and beetles), the managed forest has increasingly become a net source of carbon in recent years.

Factor: Timber Harvest

When timber is harvested, carbon in harversted biomass is removed from the system. This is accounted as a source of emissions from the Forest Land sector, and a sink in emissions in the Harvested Wood Products sector. Branches roots and stumps left behind decompose and release CO2. The operation of logging equipment is not counted in this sector's emissions, the combusion of e.g. fossil fuels in machinery is tracked within the energy sector, not the land-use sector.

Factor: Natural Disturbances

There are two main disturbances to forests that cause significant emissions: fire and insect infestation. Fires burn trees where they stand, and release massive amounts of carbon dioxide into the atmosphere immediately. Insects, such as the Mountain Pine Beetle, kill trees. The dead trees do not emit carbon immediately, but as they decay over the following decades they release CO2. (Canada may sometimes separate major natural occurrances from the anthropogenic emissions meant to be affected by emission reduction policies, TODO: follow up on this.)

Factor: Growth

Carbon is removed from the atmosphere by the photosynthesis in growing plants, especially trees. This is a major avenue of carbon removal from the atmosphere. Carbon is stored into the trunks, the branches, and the roots. Clear-cut lands are typically re-planted with a crop of trees that is all the same age. The rate at which carbon is taken up increases as the trees grow.

Factor: Land use Conversion

The amount of Forest Land may increase or decrease. When land is converted from e.g. agriculture to managed forest, it starts of with no stored carbon and begins with growth. When land is converted from forest to other purposes, it is expected to be cleared, and the stored carbon is either harvested or released by burning or decay.

Geography

You can visualize the Managed Forest as a massive band stretching across the country, generally south of the "tree line" but north of the heavily settled agricultural border areas.

  • British Columbia: Almost the entire province is considered "Managed Forest" except for high alpine areas and some northern remote zones. This includes the Interior (Lodgepole Pine, Spruce) and the Coast (Cedar, Hemlock, Douglas Fir).
  • The Prairie Provinces (AB, SK, MB): The managed forest is the northern half of these provinces. It starts where the prairies (farmland) end and the Boreal forest begins.
  • Ontario: There is a specific legal boundary called the "Area of the Undertaking" (AOU). It covers the central band of the province—from the Muskokas/Algonquin Park up to roughly the 51st parallel (north of which is the "Far North," largely unmanaged/remote forest).
  • Quebec: Similar to Ontario, the managed forest covers the southern and central parts of the province. The far northern "taiga" is generally excluded from the managed inventory.
  • New Brunswick is almost entirely managed forest and has some of the most intensive forestry in the country.
  • Nova Scotia and parts of Newfoundland are also heavily managed.

How might Canada reduce Forest Land emissions to zero?

Critical Success Factors

  • Harvest: Maximize the harvest of lumber for long-term usage, e.g. construction
  • Harvest: Minimize the wasted biomass left to decay after harvest
  • Disturbances: Minimize CO2 lost due to fire
  • Disturbances: Minimize CO2 lost due to insect infestation
  • Growth: Maximize the rate of CO2 absorbed by managed forest growth, especially into biomass that either remains after harvest in the soil, or remains for long durations as harvested wood products
  • Conversion: Increase the amount of managed land if Forest Land emissions are net negative, otherwise decrease it.
  • Conversion: minimize CO2 emissions during conversion.

Barriers

  • Trees are long-duration crops. Different species in different areas grow at different speeds, but ballpark is 40 years.
  • Clear-cut mono-culture forests are more efficient to harvest, but are be more susceptible to fire and insects (TODO: True?)
  • Most of Canada's so-called managed forests are not easy to manage, not accessible by road.
  • Fires and insects play an important and complex role in natural forest health, suppressing them would reduces emissions but brings tradeoffs.
  • Natural forests play an important part in global ecology. Biodiversity in plants and animals is desirable, but seems to be incompatible with large-scale timber harvest from managed forests.

Key Stakeholder Groups

  • Commercial Real Estate Developers
  • Construction Companies
  • Farmers
  • Mining Companies
  • Regulators
  • Timber Harvesting Companies
  • Voters

Possible Strategies (feel free to help flesh these out, contribute more)

Description Cost / tonne CO2e
Vertically-integrated mass-timber construction company
Enhanced rock weathering product for managed forests, selling carbon credits
Something to suppress insect infestations
Something to suppress forest fires