As used in this amendatory and supplementary act:
a. "Commissioner" means the Commissioner of Environmental Protection or an official designated by the commissioner.
b. "Back fire" means a controlled fire purposely ignited in the path of wildfire along the inner edge of a control line.
c. "Department" means the Department of Environmental Protection.
d. "Forest" means and includes any forest, bushland, grassland, salt marsh, and any combination thereof.
e. "Wildfire" means an uncontrolled fire burning the different types of vegetation that cover the land.