It’s been one year since the Los Angeles wildfires scorched more than 40,000 acres in Southern California, sending evacuation notices to 200,000 residents and destroying 12,300 structures. The 23-day-long fires have been the most destructive on record for the region.
Bryant University Biological and Biomedical Sciences Lecturer Robert Patalano, Ph.D., notes that, according to a World Weather Attribution scientific report, the LA wildfires were approximately 35 percent more likely to occur because of man-made climate change from the burning of fossil fuels; the excessive buildup of dead plant matter also resulted in the fires being 6 percent more intense.
As the region works to rebuild, Patalano provides insight into how the landscape is recovering and why reintroducing controlled burns and cultural fire practices may be essential for restoring ecosystem health.
A history of controlled burns
Natural wildfires have always been an important aspect of various ecosystems as they promote biodiversity and overall ecosystem health, notes Patalano. Fires reduce the buildup of dead organic matter, help release nutrients back into the soil, and trigger changes in plant community composition (i.e., how plant species assemble and interact within ecosystems). Controlled burns, in which a fire is intentionally started under carefully considered conditions, mirror the benefits of wildfires while also mitigating their risk.
“Interestingly, there is evidence for controlled burns by humans going as far back as 100,000 years ago, and this practice has been continuously used by humans as we migrated around the Earth. Aboriginal people living in Australia have used fire to manage their landscape for tens of thousands of years and, prior to the European colonization of the Americas, indigenous peoples used fire to modify the landscape across much of North America,” Patalano explains, noting that controlled burning created resource-rich habitats that provided humans with abundant gatherable plants and produced appealing environments to animals that could be hunted.
Almost all of California’s ecosystems are fire-dependent or fire-adapted and have evolved to survive wildfires; however, the state banned controlled burning in 1850 with the passage of the Act for the Government and Protection of Indians, which prohibited Indigenous cultural burning practices. Though this ban was lifted in 2022, 150 years of fire suppression resulted in the massive buildup of dead organic matter, specifically wood.
“The combination of dried vegetation, prolonged drought, and rising temperatures caused the January 2025 wildfires to burn at unprecedented intensity,” Patalano says. “California’s 2022-23 wet season, which typically runs from October 1 to April 1, was one of the top ten wettest seasons on record. This allowed for an explosion in plant growth, but the temperatures in summer and fall of 2024 were California's hottest in the last 130 years, desiccating ecosystems and killing a lot of plants which created an enormous amount of flammable material.”
Cascading effect of ecological damage
The most significant environmental consequences of the wildfires beyond physical damage is that, when fires burn through homes, buildings, and other infrastructure, they release toxic materials like lead (from lead paint), asbestos (from insulation), acids (from batteries), and volatile organic compounds, all of which reduce overall outdoor and indoor air quality.
“Not only do these get into the air as particulate matter that causes respiratory illnesses, but they also get into soil and water used by plants and animals, damaging overall ecosystem health,” he says.
The current state of regrowth in the affected areas is also of concern. Because Southern California has been heavily modified by urbanization, habitat fragmentation is a major issue.
“Fragmentation is when a habitat is divided into small, scattered blocks of native plants, typically embedded within human-dominated landscapes. Think: suburbia in America where many people’s yards consist of foreign ornamental plants that don’t fill any ecological role,” Patalano says. “As a result, fragmentation leaves only pockets of native vegetation and, in Southern California, that means the native plants that are fire-adapted have been replaced by non-native species.”
With native plants isolated to small blocks, there is less chance for native species to begin the process of succession. Additionally, says Patalano, there will be a cascading effect on the entire Southern California ecosystem now that many key species can’t recover without intervention.
Aiding the recovery process
Patalano notes that areas with mostly native species, such as parks and preserves, should recover quickly — assuming no additional disturbances sweep through the area. However, because some habitats in Southern California require two or more fire-free decades to recover from fire, it could take a long time for full restoration.
“Couple this with the major threats from rural residential development, intensive livestock grazing, local extinction of predators, and invasions of non-native plants, we may never see full recovery of this once-biodiverse ecoregion,” Patalano says.
He suggests that restoring controlled burns and other traditional cultural practices will be effective in accelerating recovery. On top of that, he says the best chance for recovery is to promote biodiversity by expanding the network of protected areas, prioritizing the recovery of the most imperiled species and natural ecological communities, and controlling and eradicating invasive non-native species.
“Only by restoring, preserving, and managing California’s fire-dependent or fire-adapted ecosystems through a combination of western science and traditional ecological knowledge can we hope to improve fire prevention strategies and reduce or limit the overall impact of wildfires in our rapidly warming world,” Patalano says.