Fire regime
Encyclopedia
A fire regime is the pattern, frequency and intensity of the bushfires and wildfire
s that prevails in an area. It is an integral part of fire ecology
, and renewal for certain types of ecosystem
s. If fires are too frequent, plants may be killed before they have matured, or before they have set sufficient seed to ensure population recovery. If fires are too infrequent, plants may mature, senesce and die, without ever releasing their seed.
The ecological need to provide an appropriate fire regime is often at odds with the principles and goals of bushfire management, which aims to manage the human and financial costs of bushfires. One of the strategies employed is frequent prescribed burns. By firing the bush at frequent, regular intervals, the bush is burnt before much fuel has built up, ensuring a low-intensity burn that is easily managed. Both the higher frequency of fire, and the low intensity, may have ecological implications; as may the tendency to burn off outside the usual bushfire season.
, where much of the vegetation has evolved in the presence of regular fires caused by the Aboriginal practice of firestick farming. As a result of this, components of the vegetation are adapted to, and depend upon, a particular fire-regime, and their survival is affected by disruption of that fire regime.
An example is found in the many Banksia
species that are both fire-sensitive and serotinous; these species are killed by fire, but fire also triggers the release of seed, ensuring population recovery. Under an ideal fire regime, a plant that recruits following a bushfire will have sufficient time to mature and build an adequately large bank of seed, before the next fire kills it and triggers seed release.
ecoregion
, covering a large portion of the U.S. state
, is dependent on periodic natural wildfires for optimal health and renewal. The increasing rural-urban fringe interface and wildfire suppression practices of the last century have now resulted in significant environmental and human safety issues and events.
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
s that prevails in an area. It is an integral part of fire ecology
Fire ecology
Fire ecology is concerned with the processes linking the natural incidence of fire in an ecosystem and the ecological effects of this fire. Many ecosystems, such as the North American prairie and chaparral ecosystems, and the South African savanna, have evolved with fire as a natural and necessary...
, and renewal for certain types of ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
s. If fires are too frequent, plants may be killed before they have matured, or before they have set sufficient seed to ensure population recovery. If fires are too infrequent, plants may mature, senesce and die, without ever releasing their seed.
The ecological need to provide an appropriate fire regime is often at odds with the principles and goals of bushfire management, which aims to manage the human and financial costs of bushfires. One of the strategies employed is frequent prescribed burns. By firing the bush at frequent, regular intervals, the bush is burnt before much fuel has built up, ensuring a low-intensity burn that is easily managed. Both the higher frequency of fire, and the low intensity, may have ecological implications; as may the tendency to burn off outside the usual bushfire season.
Australia
Bushfire is especially important in AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, where much of the vegetation has evolved in the presence of regular fires caused by the Aboriginal practice of firestick farming. As a result of this, components of the vegetation are adapted to, and depend upon, a particular fire-regime, and their survival is affected by disruption of that fire regime.
An example is found in the many Banksia
Banksia
Banksia is a genus of around 170 species in the plant family Proteaceae. These Australian wildflowers and popular garden plants are easily recognised by their characteristic flower spikes and fruiting "cones" and heads. When it comes to size, banksias range from prostrate woody shrubs to trees up...
species that are both fire-sensitive and serotinous; these species are killed by fire, but fire also triggers the release of seed, ensuring population recovery. Under an ideal fire regime, a plant that recruits following a bushfire will have sufficient time to mature and build an adequately large bank of seed, before the next fire kills it and triggers seed release.
United States
The California chaparral and woodlandsCalifornia chaparral and woodlands
The California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
ecoregion
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
, covering a large portion of the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
, is dependent on periodic natural wildfires for optimal health and renewal. The increasing rural-urban fringe interface and wildfire suppression practices of the last century have now resulted in significant environmental and human safety issues and events.