Fire is both a natural and anthropogenic disturbance influencing the distribution, structure, and functioning of terrestrial ecosystems around the world. Many plants and animals depend on fire for their continued existence. Others species, such as rainforest plants species, are extremely intolerant of burning and need protection from fire. The properties of a fire regime are changing as the natural world’s landscapes become fragmented and human influence becomes pervasive. A sound understanding of fire and its effects on ecosystems is an essential prerequisite for effectively managing this widespread ecological process.