Developing a Diverse Toolkit for Diverse Fire Regimes

By Kendall Calhoun, PhD Candidate at UC Berkeley

California witnessed one of its worst fire seasons ever recorded in 2020. Over 4 million acres burned across the state that year—more than twice the previous record. Amidst an already stressful year, these California fires seemed to only add more fuel to the flames (so to speak) of the chaos. During the August Complex, in particular, I recall seeing and feeling the orange haze day in and day out for weeks from my home in Oakland. During those weeks, it truly felt like we were surrounded, as if everything around us was burning. At the same time, my co-authors and I were occupied with writing my first dissertation chapter—a very timely piece that investigated what parts of the state are most frequently impacted by wildfires.

Wildfire has historically always been most associated with forests in the US. A history of economic and political incentives has cemented the relationship between fire and forest-health in the collective consciousness of many Americans. Many of us can vividly recall the adage of Smokey Bear – “Only you can prevent forest fires”. A simple phrase, but one that powerfully encapsulated America’s long-held obsession with fire suppression and preserving “pristine forests”. We now know that these beliefs have caused profound ecological damage in most fire-dependent forested ecosystems—and the wildlife that reside within them. Research and policy have since come a long way in recognizing the benefits of fire in several of these natural systems, yet this understanding has focused primarily, again, on forests—particularly conifer-dominated forests. But in places like California, the fire dynamic is much more complicated.

 California is composed of a deep mosaic of different ecosystem types (conifer forests, oak savannas, chaparral shrublands, etc.), all of which support an incredible breadth of biodiversity. Recent research, however, has highlighted that wildfire acts differently across these ecosystem types. Despite this, the approach to fire management and the way we continue to talk about fire has remained largely forest-focused. While investigating this history in our work, we found that over the last 20 years, only 30% of fire research and 43% of the media coverage within the state discusses non-forested wildfires in California. While we’ve become much better at understanding forest fire dynamics, the same metaphorical hammer can’t be used to solve these fire-related issues in non-forested parts of the state. But this begs an important follow-up question—where are all these wildfires happening, if not in forests?

For my dissertation, my team and I sought to answer this question and shed light on just how nuanced contemporary fire-related issues in California can be. We amassed every burn perimeter of every wildfire in California from 2000-2020. We also collected broad indicators of biodiversity from the California Department of Fish and Wildlife (CDFW) to compare the value of these burned regions towards maintaining the state’s biodiversity. We found that all of the major ecosystem types we examined (conifer, hardwood, shrubland, and grassland) have considerable amounts of acreage burning in California, with the most acreage burning outside of conifer systems. Additionally, areas of high biodiversity value (i.e. regions with lots of species and/or regions with unique species) are also burning across each of these major ecosystem types. Taken together, this underlines a major gap in our understanding and management of fire in non-forested systems in ways that may undermine our commitment to protecting human safety and biodiversity across the state. It’s also important to highlight that just because these areas are burning, it doesn’t necessarily mean these areas are negatively impacted. Just as we know that fire can have beneficial effects in forested systems, many of the non-forested systems also depend on fire regimes that they’ve co-evolved with via traditional burning by Indigenous groups. Our lack of understanding in how these mechanisms play out, however, could prove a powerful detriment in these systems as the severity and size of fires continues to escalate in what recent research has dubbed the Age of Megafire (

Megafire Perimeters, California, 2000-2020.

Caption: Figure 1 from our recent publication of the study mentioned above ( We took a look at the composition of all wildfires across the state of California from 2000-2020. Above we have the perimeters of each megafire (fires > 100,000 acres) outlined in red. Wildfires and megafires occur in both conifer and non-conifer landscapes.

The Mendocino Complex Fire brought this nuance to life for our team in 2018. The fire directly impacted our quiet research site in Northern California, burning over 3000 acres of oak woodland savanna, as well as our ongoing research and experiments. We captured the flames in real-time, recording them in perpetuity within the camera traps we had set out to take photos of deer and other critters. From this, however, we had and continue to have the important opportunity to study how this fire in particular impacts the wildlife in these oak woodland savannahs over time. My hope is that some of the work we’re doing will add to a more complete picture depicting how changing fire regimes affect Californian rangelands and their wildlife and will help us better conserve these landscapes that are an integral piece of California’s famed aesthetic.

Game Camera; 2018 Mendocino Complex

Caption: Photo taken from our camera trap grid during the 2018 Mendocino Complex Fire at the Hopland Research and Extension Center, CA, USA. (photo credit: Brashares Lab – UC Berkeley)

Three years have passed since the 2020 wildfire season. Three years and three more dissertation chapters later, and I’m still motivated to better understand how we can best protect all Californian ecosystems and wildlife from climate change and changing fire dynamics. As I wrap up my dissertation, I’m thrilled about the opportunity to work with collaborators across the state to not only further develop our understanding of how wildfires impact wildlife species across different ecosystem types, but also to investigate how changing fire dynamics may alter how people and wildlife come to interact across space and time

Written by: Kendall Calhoun

PhD Candidate, UC Berkeley

Kendall Calhoun’s (he/him) research focuses primarily on understanding the impacts of recent shifts in California’s fire regimes on native wildlife communities. He was recently named as a Smith Fellow by the Society for Conservation Biology and the Cedar Tree Foundation: 

Kendall can be reached at