Thank you. I appreciate your taking the time to read.
In response to your point, the statement does not state, "for the purpose of sustaining man" but "for the purpose of sustaining A HABITATION for man."
God in His infinite wisdom created around man an environment or as science referred to as "ecosystem" and man is given authority over it (Gen. 1:26). The many life forms within this environment are still beyond man's understanding even to this day. Only God can tell what existed before man was created and only God determines what will exist after this man of flesh. God by His word (Scriptures) spoke how it was and foretell what will it be.