Past fire regime is key to managing chaparral fires in southern California

November 30, 2001

Understanding the natural role of fire in chaparral ecosystems is necessary to effectively manage fires in southern California's shrublands, where large, high-intensity fires sweep the landscape each year, threatening lives and homes. Researchers have wondered if the natural fire regime in chaparral ecosystems has been lost because of overly effective fire suppression, and if fire managers can restore the natural fire regime with widespread prescription burning and eliminate the hazard of catastrophic fires.

USGS studies argue no to these speculations -- that there is no evidence that past fire management policies have created the contemporary chaparral fire regime dominated by massive Santa Ana wind-driven fires.

Writing in the December issue of Conservation Biology, USGS scientist Dr. Jon Keeley and co-author C. J. Fotheringham, a graduate student at the University of California, Los Angeles, refuted earlier studies that suggested the natural chaparral fire regime was one of frequent small fires that formed a landscape patchwork as a barrier to large, catastrophic crown fires. They questioned the earlier claim that destructive wildfires in southern California shrublands are a result of unnaturally high fuel accumulation from past efforts to suppress fires, and they presented arguments suggesting that landscape-scale prescription burning is not an effective means of preventing such fires. They added that limited and strategically placed prescription burns are more cost effective.

"One of the most important roles for fire managers of these ecosystems may be educating land planners on the limitations of reducing fire hazards in these natural crown-fire ecosystems," said Keeley, a research ecologist with the USGS Western Ecological Research Center at Sequoia-Kings Canyon Field Station in Three Rivers, Calif.

Keeley and Fotheringham examined a model that compared contemporary burning patterns in southern California, where fire suppression has been practiced, with patterns in northern Baja California, Mexico, without effective fire suppression. After reviewing the evidence, they concluded that the degree to which fire regimes vary between these two regions was debatable and that any differences that existed could not be conclusively attributed to differences in fire suppression.

"Indeed, historical fire records show clearly that fire suppression has not even come close to excluding fire in these chaparral ecosystems, as is the case in many Western U.S. coniferous forests," said Keeley. "Increased expenditures on fire suppression, and increased loss of property and lives, are the result of human demographic patterns that place increasing demand on fire suppression forces."
The USGS serves the nation by providing reliable scientific information to: describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

This press release and in-depth information about USGS programs may be found on the USGS home page: To receive the latest USGS news releases automatically by email, send a request to Specify the listserver(s) of interest from the following names: water-pr: geologic-hazards-pr; biological-pr; geologic-pr; mapping-pr; products-pr; lecture-pr. In the body of the message write: subscribe (name of listserver) (your name). Example: subscribe water-pr joe smith.

US Geological Survey

Related Ecosystems Articles from Brightsurf:

Radical changes in ecosystems
Earth and all the living organisms on it are constantly changing.

Global warming will cause ecosystems to produce more methane than first predicted
New research suggests that as the Earth warms natural ecosystems such as freshwaters will release more methane than expected from predictions based on temperature increases alone.

Fresh groundwater flow important for coastal ecosystems
Groundwater is the largest source of freshwater, one of the world's most precious natural resources and vital for crops and drinking water.

Re-thinking 'tipping points' in ecosystems and beyond
Abrupt environmental changes, known as regime shifts, are the subject of new research in which shows how small environmental changes trigger slow evolutionary processes that eventually precipitate collapse.

Even after death, animals are important in ecosystems
Animal carcasses play an important role in biodiversity and ecosystem functioning.

Natural ecosystems protect against climate change
The identification of natural carbon sinks and understanding how they work is critical if humans are to mitigate global climate change.

Viruses as modulators of interactions in marine ecosystems
Viruses are mainly known as pathogens - often causing death.

How to prevent mosquitofish from spreading in water ecosystems
Preventing the introduction of the mosquitofish and removing its population are the most effective actions to control the dispersal of this exotic fish in ponds and lakes, according to a study published in the journal Science of the Total Environment.

Mount Kilimanjaro: Ecosystems in global change
Land use in tropical mountain regions leads to considerable changes of biodiversity and ecological functions.

The fiddlers influencing mangrove ecosystems
The types of bacteria living in and around fiddler crab burrows vary widely between mangroves, but their functional activities are remarkably similar.

Read More: Ecosystems News and Ecosystems Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to