The word "wildfire" was once a synonym for Greek fire as well as a word for any furious or destructive conflagration. According to the Oxford English Dictionary, the earliest known usages are specifically for lightning-caused conflagrations. The modern usage may have arisen in part from people misunderstanding the expression "spread like wildfire".

Background

Wildfires are very common in many places around the world, including much of the vegetated areas of Australia, the veld in the interior and the fynbos in the Western Cape of South Africa, and the forested areas of the United States and Canada. The climates of these areas are sufficiently moist to allow the growth of trees, but feature extended dry, hot periods. Fires are particularly prevalent in the summer and autumn, and during droughts when fallen branches, leaves, grasses and scrub can dry out and become highly flammable. This is especially the case in areas where eucalypts are prevalent, as the oil of these species is extremely flammable. News reports have suggested that global warming has been increasing the intensity and frequency of droughts in many areas, creating more intense and frequent wildfires.Climate Change Link Seen in Surge of Western Blazes

Wildfires tend to be most common and severe during years of drought and occur on days of strong windsFact: date=September 2008. With extensive urbanization of wildlands, these fires often involve destruction of suburban homes located in the wildland urban interface, a zone of transition between developed areas and undeveloped wildland.

Today it is generally accepted that wildfires are a natural part of the ecosystem of numerous wildlands, where some plants have evolved to survive fires by a variety of strategies (from possessing reserve shoots that sprout after a fire, to fire-resistant seeds), or even encourage fire (for example eucalypts) as a way to eliminate competition from less fire tolerant species. Smoke, charred wood, and heat are common fire cues that stimulate the germination of seeds (Keeley and Fotheringham 1997). In 2004, researchers discovered that exposure to smoke from burning plants actually promotes germination in other types of plants by inducing the production of the orange butenolide.

However, many ecosystems are suffering from too much fire, such as the chaparral in southern California and lower elevation deserts in the American Southwest. The increased fire frequency in these areas has caused the elimination of native plant communities and have replaced them with non native weeds (Keeley 1995, Zedler 1995). These weeds create a positive feedback loop, increasing fire frequency even more (Brooks, et al. 2004).