The legislative body of any municipality desiring to proceed under this part may appoint a forestry commission for the municipality to consist of 3 members, only 1 of whom shall be a member of the legislative body making the appointment. The members of a forestry commission shall hold office for a term of 4 years and until their successors are appointed and have qualified, except that when first appointed 1 shall be appointed for a term of 4 years, 1 for a term of 3 years, and 1 for a term of 2 years. Any vacancy shall be filled by appointment by the legislative body at any regular session.