The department or its duly authorized agent may summon any able-bodied person to assist in suppressing any forest fire and may authorize any officer of the state, who is charged with the prevention and suppression of fire or the enforcement of the state fire laws, to summon any able-bodied person to assist in suppressing any forest fire within their respective jurisdictions. An able-bodied person who is engaged in the harvest of perishable agricultural crops shall not, however, be summoned to assist in suppressing any forest fire until all other available workpower has been exhausted within the respective jurisdiction of the officer issuing such summons. No member in good standing of any regularly organized fire department shall be summoned if he is available and subject to call for duty with a firefighting unit.