Science, Tech, Math › Animals & Nature When and Where Do Wildfires Occur? Share Flipboard Email Print Auscape / UIG/Getty Images Animals & Nature Forestry Pests, Diseases, and Wildfires Tree Identification Basics Arboriculture Tree Structure & Physiology The Science Of Growing Trees Conifer Species Individual Hardwood Species Tree Planting and Reforestation Amphibians Birds Habitat Profiles Mammals Reptiles Wildlife Conservation Insects Marine Life Dinosaurs Evolution View More By Steve Nix Forestry Expert B.S., Forest Resource Management, University of Georgia Steve Nix is a natural resources consultant and a former forest resources analyst for the state of Alabama. He is a member of the Society of American Foresters. our editorial process Steve Nix Updated May 04, 2018 Wildfire refers to any accidental or unplanned fire consuming plant materials, and they are a fact of life in any place on earth where climates are moist enough to allow the growth of trees and shrubs and where there are also extended dry, hot periods that make plant material susceptible to catching ablaze. There are many subcategories that fall under the general definition of a wildfire, including brush fires, bush fires, desert fires, forest fires, grass fires, hill fires, peat fires, vegetation fires, or veld fires. The presence of charcoal in fossil records show that wildfires have been present on earth virtually since plant life began. Many wildfires are caused by lightning strikes, and many more are caused accidentally by human activity. The most noted areas on Earth for wildfire include the vegetated areas of Australia, Western Cape of South Africa and throughout the dry forests and grasslands of North America and Europe. Wildfires in forests and grasslands in North America are particularly prevalent in the summer, fall and winter, especially during dry periods with an increase in dead fuels and high winds. Such periods are, in fact, called the wildfire season by fire control experts. Danger to Humans Wildfires are especially dangerous today, as rising earth temperatures combine with urban expansion into wooded areas creates the potential for tragedy. In the U.S., for example, residential development has increasingly pushed into fringe suburban or rural zones that are surrounded or integrated with woodlands or grassland hills and prairies. A wildfire started by lightning or other causes no longer will simply burn a segment of forest or prairie, but may well also take dozens or hundreds of homes along with it. Western U.S. fires tend to be more dramatic during summer and fall while Southern fires are hardest to fight in late winter and early spring when fallen branches, leaves, and other material dry out and become highly flammable. Because of urban creep into existing forests, forest fires can often lead to property damage and have the potential to cause human injury and death. The term "wildland-urban interface" refers to the growing zone of transition between developing areas and undeveloped wildlands. It makes fire protection a major concern for state and federal governments. Changing Wildfire Control Strategies Human strategies for controlling wildfires have varied over recent decades, ranging from a "suppress at all costs" approach to a "allow all wildfires to burn themselves out" strategy. At one time, human fear and aversion to fires caused professional fire control experts to make every effort to prevent fires and eliminate them immediately where they did occur. However, harsh lessons quickly taught that this approach caused a catastrophic build-up of brush, dense forests and dead vegetation that became the fuel for disastrously large fires when fires inevitably did occur. In Yellowstone National Park, for example, decades of attempting to prevent and quell all wildfires led to the inferno of 1988, when more than a third of the park was consumed by fire after many years of prevention caused a catastrophic buildup of dry tinder in the forests. This and other such instances cause the U.S. Forestry Service and other fire control agencies to radically rethink their strategies shortly thereafter. The days when the iconic symbol of the Forestry Service, Smokey the Bear, painted an apocalyptic picture of forest fires are now gone. Science now understands that fires are essential to the planetary ecosystem and that periodic cleansing of the forests through fires rejuvenates the landscape and is even essential for some tree species to reproduce themselves. Evidence of this can be seen by visiting Yellowstone National Park, where fresh new grasslands have made animal populations more robust than ever, nearly 30 years after the devastating fires of 1988. Today, wildfire control efforts are aimed less at preventing fires than controlling the way they burn and reducing the build-up of vegetation that provides the fuel that can cause fires to burn out of control. When woods or grasslands catch fire, they are now often allowed to burn themselves out under supervision, except in instances where they threaten homes and businesses. Controlled fires are even used deliberately to reduce fuel and prevent future holocausts. These are controversial measures, however, and many people still argue, despite the evidence, that wildfires should be prevented at all costs. The Practice of Fire Science Millions of dollars are spent annually on fire protection and training firefighters in the United States. An endless list of subjects on how wildfire behaves is collectively called "fire science." It is an ever-changing and controversial area of study that has important ramifications for both landscape ecosystems and human communities. A good deal of attention is now being paid to how residents in susceptible zones can minimize their risks through altering residential construction methods and changing the way they landscape their properties to provide fire-safe zones around their homes. Wildfires are an unavoidable fact of life on a planet where plant life thrives, and they are most likely to occur wherever plant life and climate conditions join to form a situation where dry, combustible plant materials are present in large quantities. Some regions of the earth are more prone to the conditions for wildfire, but human practices also have a notable impact on where wildfires occur and how big those fires will be. Wildfires become most dangerous to humans in locations where the wildland-urban interface is most pronounced.