Upon application of the owner, any auxiliary forest contract may be made subject to any provisions of law enacted subsequent to the execution of the contract and in force at the time of application, so far as not already applicable, with the approval of the county board and the commissioner of natural resources. A supplemental agreement in a format prescribed by the commissioner must be executed by the commissioner in behalf of the state and by the owner. The supplemental agreement must be filed and recorded in like manner as the supplemental contract under section 88.49, subdivision 9, and takes effect upon filing and recording.