Sustainability of timber harvest indicator: data sources and methods, chapter 2

2. Description and rationale of the Sustainability of Timber Harvest indicator

2.1 Description

This indicator compares the amount of timber harvested with the estimated national wood supply. Wood supply is the volume of timber that can be harvested from an area over a specified period of time while meeting environmental, economic and social objectives. Wood supply is for industrial roundwood supplies only and does not include other types of harvest. Industrial roundwood refers to harvested trees that are usually intended to be delivered to mills but also includes poles and pilings, and may include trees harvested for energy production, especially if it is factored into the jurisdiction's annual allowable cut (AAC) calculations. Other types of roundwood include fuelwood (used for industrial or institutional energy) and firewood (used for household or recreational energy). Under sustainable forest management, forest managers plan for harvest levels that will not impact the long-term sustainability of the forest resource.

The estimation of wood supply is affected by many factors.^{Footnote [1]} Wood supply levels are estimated for those forests that are actively managed for timber, which is a subset of forests and other wooded land. Forest land is defined as an "area of land where tree canopies cover more than 10% of the total area, and the trees, when mature, can grow to a height of more than 5 metres. It does not include land that is predominantly urban or used for agricultural purposes."^{Footnote [2]} Other wooded land is defined as an "area of land where 1) tree canopies cover 5-10% of the total area and the trees, when mature, can grow to a height above 5 metres; or 2) shrubs, bushes and trees together cover more than 10% of the area. These areas include treed wetlands (swamps) and land with slow-growing and scattered trees. They do not include land that is predominantly agricultural or urban."^{Footnote [2]}

2.2 Rationale

Canada is committed to sustainable forest management, which is defined as "management that maintains and enhances the long-term health of forest ecosystems for the benefit of all living things while providing environmental, economic, social and cultural opportunities for present and future generations."^{Footnote [3]} The Sustainability of Timber Harvest indicator is one measure of the success of Canada's forest stewardship. The indicator uses data that are reliably reported year after year.

2.3 Recent changes to the indicator

Reported harvest rates include industrial roundwood harvests only, to better align with wood supply estimates. Information on total roundwood harvests is maintained as supplementary information in the data table. Other reports may cite industrial roundwood harvests or total roundwood harvests, and care should be taken in making comparisons.

Minor adjustments to previous years' data continue to be made as source data are revised and updated.