Managing the land. For thousands of years man has cultivated the country by "cool" fires - small and slow burning, that allow animals to escape, clear the ground from dry grass and prevent hugh, devastating fires that way. Trees and bushes survive this kind of fires, and a nice side effect is also the increase of diversity of plants.
Hiking through these areas is kind of messy, because the ashes and sooth stick nicely to your sunscreen covered legs.