Species Plans and Seed Planning Units (SPUs)
Seed Planning Units (SPUs)
FGC’s Species Plans are organized by Seed Planning Units (SPU). SPUs consist of a defined geographic area and elevation band for each commercially-important tree species. SPUs serve as the foundation for BC’s tree breeding programs, seed orchards, seed planning and seed transfer limits described in the Chief Forester’s Standards for Seed Use. See Ministry website for SPU maps and spatial data.
Note: SPUs are not applicable to the recently introduced climate-based seed transfer (CBST) standards that are based on BEC variants.
SPUs are assigned unique numbers and codes. For example SPU#17 Pli BV Low, is the SPU for Lodgepole pine (Pli) in the Bulkley Valley (BV) area below 1100 m elevation. SPU #s were assigned based on their ranking derived through a tree improvement investment program (TIIP) model developed in 1999. These rankings have since changed and SPU numbers are now used only for reference. SPU rankings are updated based on new information every few years.
SPUs are also categorized to guide breeding and seed orchard investments. Program categories include: 1. Advanced-generation; 2. First-generation only; 3. genecology research only; and 4. No genetics program recommended.
In 2013, the TIIP model and SPU rankings (.pdf) were updated. This analysis included revised estimates for the net present value of the estimated incremental timber produced (based on # seedlings planted, average genetic gain of seed used in the SPU, and average site productivity), and several other criteria including climate change.
A new model for determining tree improvement investment priorities under CBST is required.
Species plans include information about the breeding activities and seed orchards for each SPU. The plans also include historical seedling needs and forecasts, nursery sowing factors, and the species’ genetic conservation status. Species Plans are listed below by SPU#.
These Species Plans were last updated in 2017. New CBST-based Species Plans are required and under development.