Areas of use

Climate based seed transfer (CBST), with the aid of assisted migration, matches the climate and latitude of a seed source, as represented by a Biogeoclimatic Ecosystem Classification (BEC) unit, with the current and near-future climate of a planting site. CBST is primarily designed to catch up with past climate change (1940s to 2016) or “adaptation lag.” Future climate change is projected forward only 15 years on the coast and 20 years in the interior, a representative quarter harvest age rotation. This conservative approach is aimed at balancing the need for adaptation to a changing climate without compromising plantation establishment. Climatically suitable (genetically) suitable areas of use are delineated by multiple BEC units, including a representative climate space projected to be suitable for that species for the year 2030. CBST Areas of Use (CBST AOU) are the same regardless of genetic origin (i.e. natural stand and orchard seed sources share the same CBST AOU). Seed and vegetative lots are assigned a ‘Seed BEC Variant’ at the time of registration to assist seed users with planning and reporting (A ‘Seed BEC Variant’ is a label used to describe a climatically (and genetically) suitable climate space.

Under CBST, seed deployment (use) and procurement (collection) areas are unique. The Excel workbook, CBST Areas of Use in British Columbia (May, 2019), identifies suitable BEC-BEC pair combinations for:

• CBST Areas of Use (seed deployment, “I have a Seedlot”: seed source-to-plantation transfers)
• CBST Collection Areas (seed procurement, “I have a Cutblock”: plantation-to-seed source transfers)

• Climate Based Seed Transfer Areas of Use

• Seedlot Selection tool version 6
• Climate Comparison Tool (XLSX, 135KB) 

Geographically Based Seed Transfer (GBST) was based on a methodology that limits seed transfers on the basis of longitude, latitude, elevation, and Biogeoclimatic Ecosystem Classification (BEC) unit. Seed planning zones (SPZ) further delineate transfer limits, with the movement of natural stand seed permitted “within the BGC zone of origin” beyond a SPZ (SPZ-B).  Please note that as of August 1st, 2022 GBST will be removed as an option from the Chief

GBST Areas of Use (GBST AOU) differ depending on genetic origin: Natural Stand, Natural Stand Superior Provenance; and, Orchard. Orchard seed transfer is delineated by a seed planning unit (SPU) - a species, seed planning zone (SPZ-A) and elevation band. SPUs are based on tested parent tree areas of use, developed through extensive provenance and progeny testing within the ministry’s tree breeding and forest genetic research program.

Under GBST, seed deployment (use) and procurement (collection) areas are the same. Every seedlot registered in the Seed Planning and Registry system and stored at the BC Tree Seed Centre has an "Area of Use", defined by application of the Chief Forester's Standards for Seed Use to the origin of a Seedlot. 

• Class A Seedlots (from Seed Orchards) -  a Tested Parent Tree AOU (eg. Pli PG Low) applies to most (combinations of Seed Planning Units). Some older Class A seedlots have a custom elevation range
• Class B Seedlots (Natural Stand Collections) - The AOU is a combination of Seed Planning Zone, Elevation Range, Biogeoclimatic Zone and/or Latitude/Longitude Range
• Class B+ Seedlots (from Superior Provenances - The AOU is a combination of Seed Planning Zones and Elevation Range

Tested Parent Tree Areas of Use - April 2009 and June 2010

• Coastal - April 2009 (PDF, 14MB)
• Interior - June 2010 (PDF, 23KB)

• GBST Seed Planning Zone/Unit and Seedlot spatial data
• Interim Measures for Climate Change, Assisted Migration of Western Larch - LW1, LW2 (May, 2014)