Evidence shows that wildfires have become more widespread and severe over the years, with the ongoing West Coast blazes bearing testament to the worrying trend.
Firefighters and farmers have tricks of their own to prevent fires from sparking and to contain them enough for successful defeat. But there might be a secret weapon that hasn’t been getting the attention it deserves.
Researchers with the University of California Cooperative Extension set out to evaluate how much fine fuel — grasses and other plants known to start fires — cattle eat and how their feeding behavior affects flame activity.
The team concluded that without cattle grazing, there would be “hundreds to thousands” of additional pounds of fine fuels per acre of land, which could lead to “larger and more severe fires.”
The team’s study results have yet to be published, but they offered their preliminary findings in a blog post published Aug. 31.
“Reducing fire hazard is not as simple as grazing rangelands to bare soil or even to low levels of fuel,” the researchers wrote in their blog post. “Widespread and severe wildfires are predicted to increase over time in California. This ‘new reality’ requires that we take advantage of all the tools in our management toolbox to protect public safety while meeting our broader rangeland management objectives.”
Planned fires, also called “controlled burns,” are often used to reduce dry fuels that can lead to destructive blazes, according to the National Park Service. These “prescribed fires” are also used to help endangered species recover and clear land for animals.
Beef cattle can be found grazing in every California county, according to the researchers, except San Francisco. In 2017, they consumed 11.6 billion pounds of fuel and roamed about 19.4 million acres of primarily private rangeland.
The team’s data comes from county crop data, Agricultural Census data and their own that they’ve collected over the years. But still, there are acres of grazable land untouched by cattle or very lightly exploited by the hungry animals, meaning “there are opportunities to improve fire safety,” the researchers wrote.
There’s also room for more cows to join the feast. The team learned that 1.8 million beef cattle grazed California lands in 2017, yet the number of cows there today “are only about 57% of their peak numbers in the 1980s.”
Sometimes, farmers purposely leave dry leafy remains on grazing lands to protect other aspects of the environment, such as future forage production, protection from soil erosion, and defense against certain weeds, the researchers explained.
Generally, fine fuels should be kept at or below 1,200 to 1,300 pounds per acre during the spring and summer to ensure flames, if a fire starts, stay below four feet — the “critical threshold that allows firefighters to safely access an area from the ground without heavy equipment,” the team said.
Conditions can differ depending on temperature, wind and humidity levels, they added.
“These fuel removal estimates are based on the best available data, but this data does not describe the complex details and variation of cattle grazing across the state,” the researchers wrote. “There is a need for more consistent and accurate accounting of cattle numbers and grazed acres across the state to better understand grazing’s impact on fire fuels.”