The Intricate Relationship Between Fire and Plants

With wildfires top of mind this summer, many communities are grieving the alteration of beloved places. Areas touched by fire can look unrecognizable when the flames subside, potentially seeming devoid of life. But amongst the ash and the charred trees, new life can be found emerging.

The Burn Scar

I was drawn to study fire ecology after living close to and working in the 2022 Hermit’s Peak Calf Canyon fire that burned in New Mexico. I had the unique opportunity to monitor forest health across the burn scar shortly after the fire was contained. Throughout the burn scar, I noticed an abundance of certain plant populations post-fire. Paying attention to the life that was coming back post-fire was deeply healing for me, as it lessened the grief I was feeling about a severely altered landscape. The more time I spent in the burn scar, the more fascinated I became with these plants and how they could persist or come back after immense disturbance.

Many plants have an incredible ability to regenerate after fire or disturbance. Post-fire, plants can regenerate or establish through several mechanisms; they can resprout from roots or rhizomes, germinate from the soil or disperse into the burn scar from populations outside of the fire perimeter. 

Fire-adapted Native Species

Here in Colorado, many native species are fire adapted. One such species is Dracocephalum parviflorum, or dragonhead mint. As the common name indicates, this species belongs to the mint family. Dragonhead mint is a prolific post-fire plant as seed germination is often triggered by heat and smoke. Another well-known species, Populous tremuloides, or aspen, is an iconic post-fire resprouter. Though mature stands of aspen often die during a fire event, new shoots can emerge from the parent root system. Chamerion angustifolium, or fireweed, is another fire adapted species native to Colorado. Post-fire, fireweed can resprout from rhizomes or establish in burn scars from an off-site location. A single plant can produce roughly 80,000 seeds per year which can easily travel long distances as they are wind dispersed. One of my favorite facts about fireweed is that it was one of the first plant species to revegetate Mount St. Helens after the volcanic eruption. 

Dragonhead mint, aspen and fireweed are just a couple of the many species in Colorado that require fire or disturbance to stimulate or establish populations. These species play an incredibly important role in kickstarting recovery and remind us of life’s ability to renew itself.

This article was contributed by Botany Seasonal Meredith Prentice.