Generally, green-up standards are applied when a proposed cutblock with an even-aged silvicultural system such as clearcut or seed tree, is located adjacent to a previously harvested cutblock or cutblocks that are also under an even-aged management system, and the total harvested area will exceed the maximum cutblock size that applies to the area.
Determination of the applicable green-up requirements for a particular cutblock should follow a systematic decision-making process based on the criteria set out in the Operational Planning Regulation (OPR). The first consideration is whether green-up requirements have been specified in an applicable higher level plan (HLP).
Higher level plans (OPR s68(4))
A cutblock is greened-up if it has attained the green-up requirements specified in a HLP for the area. However, if the HLP does not specify all three green-up requirements (height, stocking and block coverage), the OPR standards apply for the requirements not addressed in the HLP.
If there are no, or only partial, green-up requirements established in a HLP, the next step in determining green-up requirements is to classify the block on the basis of stocking as either "adequately stocked" or "not adequately stocked."
Stocking
Adequately stocked (OPR s67)
The term "adequately stocked" has been defined for the purposes of green-up requirements to establish a threshold number of trees (800 trees per hectare on the coast, 1000 in the interior) used to identify stands with sufficient stocking that can compensate for a lower green-up height and still meet green-up objectives. "Adequately stocked" is assessed on the basis of total trees of commercially valuable species rather than well-spaced trees. However, the green-up survey (see Appendix 1) incorporates the concept of an "M" value (maximum number of trees that can be tallied in a plot) to ensure a reasonable degree of stocking uniformity. The trees counted to determine whether a cutblock is "adequately stocked" must be at least 1.3 metres tall.
"Commercially valuable species" is not defined in the legislation. It would generally include the species listed in applicable Establishment to Free Growing guidebooks, regional mixed wood and hardwood stocking standards, and species included in the timber supply review as contributing to allowable annual cut (AAC).
Not adequately stocked (OPR s68(5)(b)(ii))
For cutblocks that are not "adequately stocked," the legislation establishes a default minimum stocking of 500 trees per hectare on the coast and 700 in the interior based on total trees of commercially valuable species greater than 1.3 metres in height. However, the district manager has the flexibility to approve lower stocking levels or different species if satisfied that these stocking levels will adequately manage and conserve hydrological, wildlife, recreational and scenic values. For the purposes of green-up, the specified minimum number of trees should be based on total trees.
Height requirements
Green-up height is determined on the basis of the average height of those trees that are the tallest trees of a commercially valuable species or other species acceptable to the district manager, in each 0.01 (1/100th) hectare plot included in a representative sample.
Implicit in the use of green-up height is the assumption that there is a "normal" distribution of tree heights for each species in the stand. In particular, it is assumed that the average height of the trees of a species in the stand is somewhat below the green-up height of that species (i.e., 70-90% of the green-up height). However, there are stands in which this assumption is incorrect (e.g., a naturally regenerated stand where ingress occurred sporadically over a prolonged period). These stand types may require a variance to green-up specifications to ensure green-up objectives are met (see page 8, OPR s68(6).
Green-up height requirements vary based on whether or not the stand is adequately stocked.
Height requirements for adequately stocked stands (OPR s68(5)(a)
For adequately stocked stands, a green-up height of at least three metres is required.
Height requirements for stands that are not adequately stocked
(OPR s68(5)(b)(i))
For stands that are not adequately stocked, a green-up height of at least 3.5 metres is required. The increased height requirement ensures the stand is comprised of larger trees at the time green-up is achieved in order to compensate for the lower stocking.
Block coverage requirements (OPR s68(3))
To satisfy green-up objectives, the requirements for height, stocking and species must generally have been met on at least 75% of the net area. The 25% not required to meet green-up provides a net down allowance for portions of the net area not meeting the height, stocking and species requirements for green-up. The 25% may be scattered in patches throughout the net area or concentrated in a single portion.
The district manager may specify either a higher or lower coverage requirement than the 75% as may be appropriate to adequately manage and conserve hydrological, wildlife, recreational and scenic values. Alternatively, the district manager may specify that only a specific portion of the cutblock need meet green-up requirements. However, this portion must be immediately adjacent to the proposed cutblock and of sufficient size to adequately manage and conserve forest resources.
For example, on large cutblocks, if a specified proportion of the previously harvested area immediately adjacent to the proposed cutblock meets green-up requirements, green-up objectives may be satisfied even if the total percentage of the net area not meeting green-up exceeds 25%.
