Yes, the listed rule for Forester is a degree or a state or provincial licence, so a provincial registration on its own can carry the credential requirement. The employer letter must still describe professional forestry work.
Rely on the registration and document it properly
Present the current registration certificate and, if available, a letter of good standing from the provincial body, because an expired or lapsed registration does not satisfy the rule. Attach the diploma and any continuing-education record as supporting material, but let the registration do the work. The question officers actually ask is whether the job is forestry, so the employer letter must describe planning, assessment and management of forest land rather than machine operation or crew supervision alone. If the applicant will also supervise a harvesting crew, say so and show that the professional planning work is the substance of the role. Do not attempt to convert a woods-operations job into forestry by adding words to the letter; the officer may ask what the applicant does on a typical day and the answer must match.
Hypothetical example: an urban planner holds a current provincial registration but is offered a role whose daily work is drafting subdivision applications rather than professional planning analysis. The first review would compare a weekly duty list with the listed profession and identify whether the registration and the proposed work point to the same occupation. Obtain a signed description from the hiring manager before travel, then rehearse a plain explanation of who directs the work. A credential settles only the qualification question; it cannot repair duties that are really administrative or construction supervision.