How can grazing on rangelands boost wildfire resiliency?
UC researchers, collaborators quantify effects to help guide land management
In 2020 a group of UC ANR researchers and collaborators began using prescribed burns to test how wildfire might behave across grasslands that they treated to mimic various levels of grazing intensity. At nine locations across the state, the team manipulated treatment strips and measured how fast the fire moved, how high the flames got and how hot the fire became.
“We're trying to understand, in a specific and quantitative way, how grazing in grasslands affects fire behavior,” said UC Cooperative Extension Livestock and Range Advisor Matthew Shapero. “This is acutely relevant for California today because we're searching for tools to help us be more fire-resilient and to be safer as communities, and we also want to provide specific guidance for practitioners to help them understand how their land management activities will affect wildfire behavior.”
The concept was developed by range ecologist Roxanne Foss of Vollmar Natural Lands Consulting. Foss, who was previously a graduate student in the rangeland program at UC Berkeley, teamed up with Shapero, UC ANR specialist in rangeland planning and policy Luke Macaulay (now at the University of Maryland), and other collaborators including Livestock and Range Advisor Jeffery Stackhouse and Fire Advisor Lenya Quinn-Davidson.
“Our collaboration includes cattle producers, fire suppression agencies and private industry, so we have a lot of different perspectives and ideas, which makes for a good research project,” Shapero noted.
“This project would not have been possible without the Cooperative Extension network, as well as support from CalFire, local prescribed burn associations, and public and private landowners,” Foss added. Funding for the study came from the UC Davis Russell L. Rustici Rangeland and Cattle Research Endowment.
Photos by Vollmar Natural Lands Consulting
UC ANR partnerships crucial to conducting research
It hasn’t been easy collecting the data because prescribed burns are complicated events, often entailing years of planning and last-minute cancellations or rescheduling.
“Doing replicated work in prescribed fire is very, very difficult, especially at the statewide scale,” said Stackhouse. “We were able to pull it off utilizing every partner that we collectively have. That speaks to ANR’s ability to cross boundaries better than some other groups at the statewide level.”
Because land management planning and strategy is formalized and codified, being able to rely on firm numbers is critical. Industry stakeholders can also better quantify the benefits that their grazing is having in being more fire safe.
“We are confirming what we already know intuitively, that grazing to remove biomass fuels from the system is going to reduce fire behavior,” Shapero said. “But the value here is understanding exactly how that happens, and the specific levels of grazing, as measured by pounds of biomass per acre, that translate to fire resiliency.”
“The information can be applied directly to how people are managing their land,” said Quinn-Davidson. “And it was great to have a project that spanned the state.”
One takeaway from their research is that intense grazing is not needed to reap some benefits. They have seen meaningful reductions in flame length even with moderate grazing, which has implications for protecting natural resources.
“Our results show that there are key biomass thresholds that impact critical fire behavior characteristics,” noted Foss. “Amazingly, these thresholds were valid across the study sites statewide. Having tangible biomass goals will support land managers in planning, implementing, and monitoring the success of fire fuel reduction projects on grazed grasslands.”
Photos by Vollmar Natural Lands Consulting
Researchers urged to connect with advisors on the ground
Early on, the team took advantage of UC ANR funding for specialists to travel to other counties, allowing them to deliver content, participate in each other's workshops and do prescribed burns together. “That support is what allowed our project to grow and develop,” said Shapero. “It would be great if ANR could expand travel support for networking and research.”
“In the first year or two as a specialist, it’s really important to get out and meet as many people as you can,” added Macaulay.
“We need more specialists to work with advisors across the state,” said Stackhouse. “We need systemic changes to encourage people to leave campus and partner around the state. Specialists are willing to help and provide advice if you call them but getting them to the outer counties is challenging. Advisors that are closer to campuses have a much different experience than those that are in the far corners of the state.”
Macaulay recommends that specialists connect with advisors to understand what's happening on the ground in the ranching community, the fire community and the ecology community. “They have so much firsthand experience that can enrich a research project in ways that you can't do through literature review,” he said. “They can help guide what will be useful and impactful.”
This project underscores the importance of connection with the campus specialists who tie into the broader research community and the research ideas they're interested in. “Roxanne's leadership was key,” said Macaulay. “She had a personal interest in this topic and the only information we found had been published in the ’80s. Nobody had looked at it in a close way.”
The team expects to wrap up the project in 2023 and will publish guidance based on their findings to benefit the public.