Evolving alongside fire for millions of years, California native plants have developed many different strategies to withstand or recover from fire. While we often think of “fire-adapted” as meaning “less flammable,” some adaptations to fire are not related to a plant’s flammability, but rather to its ability to regenerate after fire.
Arctostaphylos canescens, commonly known as hoary manzanita, is one of these fire-adapted species. Its seeds actually require fire to continue their life cycles. Hoary manzanitas produce hard, round seeds that can lay dormant in the soil for decades. When a fire occurs, the seed’s protective covering is broken by the high heat and the smoke stimulates germination of the embryos inside. Mature hoary manzanitas are not fire-resistant and can burn intensely during fires. Their adaptations to fire lie in their fire-following seeds rather than their ability to withstand fire.
Other plants, like the coast live oak (Quercus agrifolia), are adapted to resist fire and are less flammable. Coast live oaks have thick bark that protects their inner tissues from high heat, and they are able to resprout quickly after fire if branches are damaged. Unlike the hoary manzanita, the acorns of the coast live oak are not well adapted to survive fire, so the continuation of the coast live oak’s life cycle relies on the ability of mature trees to survive and produce acorns after fire.
Native plants are adapted to a specific pattern of fire behavior and frequency shaped over time by lightning-caused wildfires and cultural burning by Indigenous peoples. Colonization and the subsequent exclusion of both cultural burning and wildfires over the past two centuries have changed historic fire patterns, resulting in a loss of fire-adapted species and an increase in wildfire risk to communities.
The CCRCD works with landowners to restore historic fire patterns through vegetation management and the reintroduction of prescribed fire. Although it may seem counterintuitive to light fires as a wildfire mitigation strategy, prescribed fires are strategically planned to capture the ecological benefits of fire–such as reviving native plants–while also increasing community resilience to fire by reducing fuel loading and the potential for future ignitions. Sustainable land management doesn’t mean preventing fire altogether, but building ecological conditions that promote the smaller, lower-severity fire behavior of the past.*
Fire is an integral part of California’s ecology. While we can and should protect our communities from catastrophic wildfire, we must also recognize that fire is critical for the conservation of our natural landscapes.
*Chaparral ecosystems are an exception, as they’re adapted to burn at high-severity.
