As used in sections 320.300 to 320.310, the phrase “volunteer fire protection association” means any fire department, including a municipal fire department, which is staffed by volunteers and organized for the purpose of combating fires in a specified area. The provisions of sections 320.300 to 320.310 shall apply only to volunteer fire protection associations either partially or wholly funded by membership or subscriber fees and shall not apply to fire protection districts supported by local tax revenues, or which have contracted with a political subdivision to respond to fires within the area of an association’s boundaries.