“Apocalyptic.” The devastation of the wildfires that blazed through Los Angeles in January has cast a new light on the catastrophic consequences and losses that wildfire activity can cause. 

Unfortunately, it is not a one-off event. We only need to look to 2017 to find another deadly wildfire year in California, where almost 11,000 structures burned and 47 lives were lost. Katherine Siegel, a professor and interdisciplinary environmental scientist at the University of Colorado, witnessed it firsthand. 

She wrote to The Varsity in an email: “I was living in California in 2017, when the Tubbs Fire, the Atlas Fire, and the Thomas Fire ripped through rangeland ecosystems, destroying entire communities and causing multiple deaths.” This sparked her interest in understanding how land management practices affect wildfire activity because, after all, the land fueled the wildfires.

Past US federal management policies, such as the “10 a.m. policy” act — which aimed to suppress all fires by 10:00 am the following day — have contributed to the proliferation of invasive plants that grow faster and taller than native species. This, combined with rising temperatures and residential development in wildlands — areas prone to fire activity — has paved the way for more intense and severe wildfire seasons.

Cattle grazing — a method of feeding cattle by letting them roam and consume wild vegetation — has emerged as a low-cost, convenient tool in the wildfire-fighting kit. How do they mitigate fire? The answer is simple: they eat the fuel. 

This process of cattle grazing creates patches in the vegetation, breaking its continuity. They also trample the ground, mixing the fuel with soil, which decreases flammability. And as a bonus, there are already plenty of grazers on the west coast. In California, cattle grazing occurs over one-third of the land.

Following the 2017 wildfires, Siegel had the opportunity to work with rangeland and livestock specialists to estimate the changes in burn probability associated with cattle grazing. “Ranchers [had observed] that the rangelands they had grazed did not burn, while their ungrazed rangelands burned in recent fires.”

Estimating the impact on burn probability from cattle grazing

Siegel’s team set out to collect the necessary data to see if there was a link between grazing levels in a specific region and burn probability. They contacted private landowners across various counties in California to assess grazing activity on their property and combined that information with land-cover data — e.g. shrubs and grass or larger conifer trees — and fire history. 

The team explored the correlation between burn probability and cattle grazing. Other factors, such as population density and the weather, could also influence fire likelihood. They found that in regions like North Bay — a sub-region of the San Francisco Bay — and the Central Coast area — which spans from the north of Los Angeles to the south of San Francisco — the grasslands’ burn probability decreased by about 55 per cent and 50 per cent, respectively. 

In a follow-up research paper in Ecology and Society, they found that intensifying grazing activities reduced burn probability by 82 per cent in Napa and Sonoma counties.

Part of a bigger fire management puzzle

The Varsity asked Siegel if this meant we could charge ahead with cattle for fire management.

“I see it as just one piece of a complicated puzzle when it comes to wildfire mitigation and adaptation,” she wrote. “[The rest of the] pieces include climate change actions, urban planning… and broader fuel management through tools like prescribed fire.” Prescribed fires involve planning and controlling fires to achieve specific management goals, such as reducing the amount or structure of certain fuels, like fine fuels that catch and spread fire quickly. 

Like any mitigation strategy, the answer is not straightforward. However, to inform policy on other solutions, research is essential. Ultimately, we are not completely helpless in extreme wildfires; we can always call on the cattle — and they might just answer the call.