Fire Severity and Bark Beetle Infestation in California

Elizabeth Pascale, Courtney Lewis, and Rebecca Fisher

Motivation

• Climate change altering ecosystem characteristics

• Suitable habitat for bark beetle increases to encompass more forests in the Western United States

• Increased fire severity in Western United States

California Fires 1998 - 2001

California Fires 2002-2005

California Fires 2006 - 2007

fireanimation.gif

Click below for animation

Fires 1998-2007

Fire Threat

Fire Threat to People

Urban Fire Threat

Forest Cover

Fire Threat vs. Forest Cover

Bark Beetle Risk

California forest acres at risk (identified in red on the map; risk is defined as 25% or more volume killed) to bark-beetle caused tree mortality over the next 15 years.

Bark Beetle vs. Forest Cover

Bark Beetle in CA Forests

• Aerial survey results from 1994-2007 depicting the percent area flown with insect injury and percent of average precipitation throughout California. Source: USDA FS-Forest Health Monitoring

Source: www.fs.fed.us/r5/spf/fhp/socal/2008WBBconditions052908.pdf

Bark Beetle Acreage

San Bernadino:

360,936.98

Los Angeles:

4,356.47

Riverside:

165274.00

San Diego:

80,245.01

Bark Beetle vs. Fire

Severity of bark beetle induced mortality and its correlation to Fires in 2003.

Results

• In 2003 there is a noticeable correlation between dire severity and bark beetle induced mortality

• Lack of information to evaluate current or future trends

• To do so would require more time and more specific data collection

Conclusions

Focus:• Identifying correlation between wildfires and bark beetle

infestation in California. • Created maps with background information on California

– forest cover fire risk, – fire risk near urban area

• Attempted to map climate change but found the data hard to access.

• Data for bark beetle infestation/mortality was also very difficult to find, but we were able to find raster data for 2003 bark-beetle related mortality in Southern California and superimpose it over 2003 fire data.

• Found vector data from the U.S. Census of insect-related tree mortality for 4 Southern counties in 2003

• 1998-2007 fire data was extracted and isolated to create a different layer for each year (as well as an animation showing the fires) from a table containing data from California fires since as early as 1900.

• We wanted to show a similar time trend with bark beetle infestation/mortality, but the information is lacking.

• This might actually explain the state's weak response to bark beetle outbreaks and subsequent fires. We also found data for bark beetle infestation risk.