Volume 1 - Resource Management
Chapter 2 - Silviculture

Policy 2.13 - Commercial Thinning

Effective Date: 16-Jan-95
Updated: 15-Oct-97
Responsible Branch: Forest Practices Branch

Resource Management Volume Table of Contents | Amendment Log

Scope

This policy establishes Ministry guidelines and responsibilities for commercial thinning operations. This policy applies only to even-aged stand management using commercial thinning. It does not apply to uneven-aged management.

Policy

It is the policy of the Ministry that commercial thinning will be used to provide a proportion of the Provincial Allowable Annual Cut. This will be done to allow flexibility in timber flow and improve environmental, economic, and social values. Commercial thinning should be considered in forest-level planning (Timber Supply Analysis and Land and Resource Management Plans) as a means of achieving strategic forest management objectives.

Commercial thinning may be used to achieve the strategic objectives listed below:

  • maintain or enhance wildlife habitat or other important non-timber values
  • provide local employment
  • improve forest health
  • increase stand value
  • maintain, increase, or change timing of timber availability

Commercial thinning will be planned and implemented within the regions and will be included in regional five-year Forest & Range Resource Programs.

District Managers should pursue opportunities for commercial thinning when they will fulfill management unit strategic objectives and where there are current or projected markets for the thinned wood.

Levels of commercial thinning are anticipated to increase significantly due to current and predicted timber shortages. Within 10 years commercial thinning is anticipated to account for 10-15% of the B.C. annual harvest volume.

Definitions

Commercial thinning is applied under even-aged management as opposed to selection silvicultural systems which create or maintain uneven-aged stands.

Commercial thinning is a partial cut in stands where timber removed in thinning is sold. Commercial thinning provides an interim harvest, while maintaining or redistributing stand growth without reducing the potential of the residual stand.

Guidelines for Candidate Stands

Candidate stands should generally have the following characteristics:

  • sufficient live crown on potential leave trees to allow a satisfactory response to thinning
  • sufficient merchantable stems, and favourable harvesting conditions, which will give a positive or break-even financial return from thinning
  • suitable height/diameter ratio to ensure stability of crop trees
  • likelihood of improved economic, biological, and/or social value after thinning

Silviculture Prescription

A Silviculture Prescription (S.P.) is required for all commercial thinning operations. The SP will, as a minimum, contain details on residual stand conditions and stocking levels and maximum limits for site distrubance and stand damage. Residual stocking levels must reflect the specific management objectives for that site. The SP will specify a free growing assessment period during which a free growing survey must be completed and all SP obligations must be met.

Monitoring and Reporting

All commercial thinning operations will have a post-harvest assessment immediately after harvesting to determine final stand structure, species composition, soil disturbance, stand damage, and waste.

The date for a free-growing survey should normally be set for 2 years after commencement of commercial thinning, in order to allow assessment of the residual crop for such factors as blowdown and snow break. Stands deemed susceptible to such factors should be given a later date for a free-growing survey. The free-growing survey confirms that the SP obligations have been met and triggers generation of a new inventory forest cover label.

Thinning Standards

In cooperation with Silviculture Practices Branch, Regional Managers will develop regional guidelines for commercial thinning standards. Topics to be covered in these guidelines will include residual stand structure, worker safety, forest health, wildlife habitat, biodiversity, and salvage of mortality.

Tenures and Licences

Standard cutting permits and timber sale licences will be used to authorize commercial thinning. The cutting permit and timber sale licences must incorporate the standards.

For Small Business Forest Enterprise Program (SBFEP) commercial thinning oprerations:

A Timber Sale Licence (TSL) should be advertised for competition under Section 20 of the Forest Act. If there are not applicants for a competitive sale or the District Manager believes direct awarding a TSL is warranted, the Ministry Policy on sales under Section 23 of the Forest Act (no advertising required) should be followed.

If no applications are received for an advertised Timber Sale, the District Manager must determine if the non-economic reasons for performing the commercial thinning are sufficient to warrant continuation of the project. If the project is still deemed necessary then:

The District Manager may enter into a silviculture contract to perform the thinning. The Ministry retains ownership of the decked logs. These will be sold competitively.
 
In limited cases where no applications are received for an advertised Timber Sale, the District Manager may direct-award a Timber Sale, under Section 23 (1) (e) of the Forest Act, in conjunction with a silviculture contract. Normal competitive rules apply for the silviculture contract. This option should only be used in cases where:
  • the harvesting is necessary for other than timber extraction purposes - for example, maintenance of forest health
  • timber utilization must be encouraged
  • the risk of the contractor unduly removing crop trees is low
  • competition for the decked logs would be unlikely if they were sold separately

Multi-year timber sale licences within the SBFEP may be considered when necessary to encourage equipment purchase or development by the private sector for commercial thinning operations. Such licences would be sold on a competitive basis and must identify the area to be thinned and estimated volumes for the full term of the licence.

Cut Control


All wood harvested in accordance with Utilization Standards Policy and contract utilization specifications for a commercial thinning operation will be charged to the relevant licences allowable annual cut (AAC), or to the annual commitment in the SBFEP.

Stumpage and Costs

Stumpage rates will be determined according to the appraisal manual. Penalties will be assessed for, but not limited to:

  • excessive removal of trees during a commercial thinning operation
  • excessive damage to residual trees
  • excessive damage to the site

The regulation will specify the amount of the penalty.

Responsibilities

Director, Silviculture Practices Branch: [OPR]

  • develop guidelines, procedures, and standards for commercial thinning and give guidance to the Ministry of Forests Executive on necessary amendments to the Silviculture Practices Regulation in relation to commercial thinning
  • monitor and promote improvements in the types of equipment used and the techniques followed in commercial thinning
  • ensure data is collected to evaluate the suitability of the standards
  • develop training for commercial thinning
  • monitor the application of guidelines, procedures, and standards within the context of this provincial policy
  • with the Director, Research Branch, estimate the anticipated quantitative and qualitative effects of commercial thinning regimes

Chief Forester:

  • consider the role of commercial thinning when determining the AAC for a Tree Farm Licence (TFL) or a Timber Supply Supply Area (TSA)

Director, Research Branch:

  • carry out research to estimate the anticipated quantitative and qualitative effects of commercial thinning regimes on growth and yield, biodiversity, and wood value

Director, Resource Tenures and Engineering Branch:

  • monitor the tenures and methods of awarding harvest rights used in commercial thinning operations and advise where changes are appropriate
  • report the amount of commercial thinning occurring annually in the province in the Ministry of Forests Annual Report
  • monitor the application of procedures and guidelines within the context of this provincial policy

Director, Revenue Branch:

  • develop and maintain representative cost and market-value estimates for commercial thinning operations
  • develop and maintain cruising methodology for commercial thinning operations
  • develop and maintain appraisal procedures for commercial thinning

Director, Resources Inventory Branch:

  • update the forest inventory based on new inventory forest cover labels prepared after commercial thinning treatments
  • install growth and yield monitoring plots on operationally thinned areas

Regional Manager:

  • monitor and inspect the Districts' commercial thinning programs
  • develop and implement provincially consistent regional guidelines and procedures
  • monitor licence-holder management plans to ensure commercial thinning potential is assessed
  • monitor Land and Resource Management Plans to ensure commercial thinning potential is assessed
  • implement training for commercial thinning

District Manager:

  • only approve silviculture prescriptions which meet standards for commercial thinning
  • ensure adequate monitoring and enforcement of standards for commercial thinning
  • ensure staff is appropriately trained
  • ensure that commercial thinning treatments as described in SPs will maintain or improve forest health and will not result in excessive damage to residual trees or to the site
  • ensure that stumpage rates are known prior to tendering a silviculture contract for a commercial thinning operation
  • monitor Licencee Development Plans to ensure commercial thinning potential is assessed
  • set the utilization requirements for each commercial thinning cutting authority
  • ensure the corporate database is updated

References