Sea to Sky Old Growth Management Area (OGMA) Project - Guiding Principles
This document is intended to provide consistent direction for forest professionals during completion of
OGMA planning in the Sea to Sky District.
The following principles have been considered and are described for the following topics:
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Base layer information for BEC analysis
Maintaining data integrity
Participation and cooperation of stakeholders
Consultation with First Nations
Desirable OGMA features and principles for boundary modification
a. When expanding OGMA size
b. When reducing OGMA size
6. Legal Order provisions for amendments
1. Base Layer information for BEC analysis
OGMA targets have been recently re-calculated using current Crown Forest Land Base
information and Terrestrial Ecosystem Model coverage, located in the BC Geographic
Warehouse: WHSE_TERRESTRIAL_ECOLOGY.STE_TEM_ATTRIBUTE_POLYS_SVW
Other legally established or recognised data layers to consider:
- Constraints (WHAs, parks, conservancies, etc.)
- Forest Cover/VRI
- Private land (Integrated cadastral fabric)
- Excluded land (right of ways, reserves, woodlots, etc)
2. Maintaining data integrity
The district office will maintain all data necessary for this project, apart from proprietary
information held by each licensee or consultant.
When submitting shape files to FLNR, please ensure data follows the same format as existing
information, such as for OGMA number and status (legal, draft, retired). Format information can
be provided by the district (contact Paul Filippelli).
3. Participation and cooperation of stakeholders
The success of this project is in large part dependent on the timely participation and
cooperation by forest professionals responsible for their respective chart areas located in
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various LUs throughout the district. For those LUs where more than one chart area is situated,
OGMA location throughout the LU should be considered, i.e. the equitable spatial distribution of
OGMAs. No one area, including parks, should be targeted solely for OGMA location.
4. Consultation with First Nations
First Nations consultation continues to be a legal requirement and is of foremost importance
when considering OGMA establishment, deletion or relocation. In many cases forest licensees
may be conducting services on behalf of a First Nations. FLNR will proceed with FN consultation
during the project, and encourages licensees to apprise FN clients of progress regarding changes
to OGMA location. Where FN chart areas are located outside their traditional territory, licensees
remain responsible to consult with the appropriate FN.
5. Desirable OGMA features and principles for boundary modification
The following describe the principles that guide desirable OGMA features and location:
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OGMA minimum size is 2 hectares
OGMAs should be spatially distributed across the LU
OGMAs should be drawn to represent small (2-10 ha), medium (11-35 ha) and large (>36 ha)
patch sizes across the landscape. Some large patches that provide forest interior habitat
conditions are required, e.g. contiguous patches >36 ha and round in shape (assuming 200m
edge influence).
Long, narrow OGMAs are not preferred, unless at some point in their design they provide a
contiguous upslope linkage. For example, avoid narrow leave strips between cut blocks and
riparian areas or roads, or adjacent to slide tracks. At their narrowest point, OGMAs should be at
least 100 m wide.
Total volume of forest within OGMAs should not be less than 300 m3/ha (i.e. avoid poorly
stocked stands)
Stand site index should not be less than 10, and some OGMAs with higher site index should be
included to be representative of forests at the landscape scale
Minimize height class 2 stands in OGMAs
Tree species composition in OGMAs should be representative of tree species that occur across
the landscape
Maximize capture of old forest, minimize amount of younger forest. It is acceptable to consider
expanding OGMA size by including age class 8. Age class 7, with good recruitment potential
(high site index) can be used when old forest is not available.
Newer and more detailed aerial imagery (e.g. SPOT 5) should be reviewed to help to guide
boundary locations, especially where stands have been broadly delineated and defined.
Balance the distribution of OGMAs across the landscape including valley bottom areas. Utilize
identified Wildlife Habitat Areas or Ungulate Winter Ranges (or other constrained areas) as a
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priority, followed by non-contributing, partially contributing, and contributing THLB, with the
aim to reduce potential impact on future forest harvest opportunity.
Scale used for delineation is generally 1:20,000 with some variance depending on image quality
(a) Rationale for addition or expansion of OGMA boundaries to meet target amount:
- Expand/add OGMA where appropriate stand conditions are available in constrained areas, e.g.
ungulate winter range, grizzly habitat, or where forest is classed as non-contributing THLB
- Combine small OGMAs into larger OGMA areas, where possible to provide forest interior habitat
- Round boundary edges to follow stand boundaries (using image interpretation)
- Expand OGMA along riparian areas to include both sides of creek, or where unique old forest
types are located
(b) Rationale for deletion or reduction of OGMA boundary to get down to OGMA target:
- Reduce/delete OGMA in areas where stand site index is less than 10, or height class 2
predominates
- When over target, reduce from small OGMAs first (while maintaining spatial distribution)
- Reduce/delete OGMA in non-treed areas, gullies and blowdown along cut blocks (using image
interpretation)
- Reduce/delete OGMA where the stand is leading alder (using image interpretation or VRI)
- Reduce/delete OGMA where non-productive areas are obvious or where land base is classed as
excluded (using image interpretation)
- Delete OGMAs where area is <2 hectares and the OGMA cannot be reasonably expanded with
appropriate adjacent forest
- Delete OGMAs where volume is substantially less than 300 m3/ha, and other conditions such as
tree height and site class are also unfavourable, regardless of size.
6. Plan Content, Legal Order provisions, and other processes
As FLNR proceeds through editing and establishing OGMAs there may be other opportunities for
providing input into existing legal orders and SRMPs. Other processes, such as those describing
timely data management and requirements for OGMA amendments, have been identified for
potential improvement. FLNR has recently established a provincial OGMA working group to
examine issues such as these and feedback from licensees may be requested from time to time.
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