Cattle grazing reduces fuel and leads to more manageable fire behavior

Abstract

Cattle play an important role in wildfire management by grazing fuel on California rangelands. The benefits of cattle grazing have not been thoroughly explored, though. Using statewide cattle inventory, brand inspection and land use data, we have estimated that cattle removed 11.6 billion pounds (5.3 billion kilograms [kg]) of non-woody plant material from California's rangelands in 2017. Regionally, these reductions varied between 174 and 1,020 pounds per grazed acre (195 to 1,143 kg per hectare). Fire behavior is characterized in this paper by flame length. Fire behavior models suggest that these regional fuel reductions lower flame lengths, and lead to more manageable wildfires. In addition, fire-based models show that cattle grazing reduces fuel loads enough to lessen fire hazards in many grazed areas. Moving forward, there may be significant opportunities to expand strategic grazing on rangelands to add extra layers of protection against wildfires.

Cattle Grazing Moderates Greenhouse Gas and Particulate Matter Emissions from California Grassland Wildfires

“…In 2017, beef cattle grazing removed an estimated average of 668 kg per ha (596 pounds per ac) of forage/fuel from grazed rangelands throughout the state. The amount of fuel consumed per acre varied by region, from approximately 195 kg/ha (174 lbs/ac) removed in the Southeast Interior region to 1143 kg/ha (1020 lbs/ac) removed in the San Joaquin/Sierra region [22]. The regions used by Ratcliff et al (2022) [22] are shown in Figure 1.…”

“…The amount of fuel consumed per acre varied by region, from approximately 195 kg/ha (174 lbs/ac) removed in the Southeast Interior region to 1143 kg/ha (1020 lbs/ac) removed in the San Joaquin/Sierra region [22]. The regions used by Ratcliff et al (2022) [22] are shown in Figure 1. The total estimated fuel reduction by cattle in California in 2017 was 5.3 billion kg (11.6 billion lbs).…”

“…Beef cattle are by far the most prevalent grazing animal on California rangeland [20,21]. Grazing can be used as a fire management tool, and fuel reduction through livestock grazing is a goal frequently included in management plans by state, regional, county, and local agencies [22].…”

“…At the same time, grazing also results in the removal of billions of pounds of forage across the state, which reduces the amount of fuel available for combustion in the event of wildfire [22] and creates patchiness of fuel which can reduce the fire's spread across the landscape [38][39][40][41]. In 2017, beef cattle grazing removed an estimated average of 668 kg per ha (596 pounds per ac) of forage/fuel from grazed rangelands throughout the state.…”

“…Per-acre forage consumption in each region was based on Ratcliff et al (2022) [22], which showed that average forage consumption per acre by beef cattle varies by region. The regional consumption values from that study were (1) Central Coast region = 230 lbs/ac, (2) North Coast region = 450 lbs/ac, (3) Sacramento-Sierra-Cascade region = 246 lbs/ac, (4) San Joaquin-Sierra region = 588 lbs/ac, (5) South Coast region = 23 lbs/ac, and (6) Southeast Interior region = 16 lbs/ac.…”