Fire Ecology and What Happens After Forest Fires

What Happens After Forest Fires

Ever wonder what happens after forest fires? Fire ecology— or, the study of the role of forest fires in ecosystems — can help us understand. Fire ecologists study the origins of fires, what influences their spread and intensity, their relationship with ecosystems, how controlled fires can be used to maintain ecosystem health, and what happens in nature after fires has occurred. As Canada experiences the worst start to its fire season in history, and many other parts of the world follow, we are already thinking about what happens next. Some areas will be able to regenerate on their own, while others will require swift reforestation efforts to support their chances of a healthy forest fire recovery. 

Can Forests recover after forest fires?

Why can some places recover after forest fires naturally, but others can't? Answering this question requires learning from the experts, and looking at the biotic (related to living things) and abiotic (not derived from living organisms) components of an ecosystem. After forest fires have occurred, environmental professionals assess the scope of the damage, asking questions like:

How many trees were killed? 

Was the soil seed stock destroyed? 

How is the local climate affected?

Will the ecosystem be able to regenerate on its own?

If an ecosystem is able to regenerate with minimal help, great! If not, that's where One Tree Planted can help by planting trees for forest fire recovery. However, before tree planting can take place, a few things usually need to happen:

• Removing extra debrislike snags (dead trees) and brush so they can't provide fuel for future fires, but leaving some to provide wind protection and improve water retention for newly planted trees. Some wildlife species, like the black-backed woodpecker, also rely on snags to nest and forage the insects that are drawn to fire-affected areas.
• Assessing the soil health and erosion risk, and remediating as needed. Fires can actually improve the nutrient profile of the soil by breaking organic matter down into a usable form. But they also remove the most effective anchor — trees — holding everything together, which increases the risk of erosion and soil loss. 
• Determining whattree species will provide the most benefit— for example, during a recent effort to reforest parts of British Columbia that were destroyed during the historic 2017 wildfire season, we planted Trembling Aspen, which has a high water content and helps slow the spread of fires by creating a natural protective barrier.

After the area has been thoroughly assessed, and it has been determined that reforestation would be the best approach to support landscape recovery, that's when we plant trees. If the damage isn't too severe however, nature might just be able to bounce back on its own.

The Benefits of Forest Fires

It's important to remember that in some ecosystems, fire has historically played an integral role in shaping and maintaining the landscape. As a result, many native plant and animal species have developed incredible strategies to withstand blazes. California’s giant sequoias depend on fire to reproduce: their serotinous cones, which are glued tightly shut with pine resin, and require concentrated heat to release the mature seeds inside. And their thick, fire-retardant bark protects sensitive inner tissue, allowing them to withstand low-intensity surface fires. Othertree specieswith fire-aided dispersal strategies include jack pine, table mountain pine, and lodgepole pine (one of the first to grow after a fire). And many chaparral plants like coffeeberry, long sepal globemallow, and snow brush have coated seeds that need direct or indirect contact with intense heat, smoke, and/or nutrient release to trigger germination. Underneath the soil often lays a rich seed bank just waiting for the right signals. Species like Indian paintbrush, scarlet gilia, Oregon sunshine, and Washington lily are just a few examples of beautiful fire-activated wildflowers. Fungi can also benefit from forest fires — and the experienced mushroom hunter knows that recent burn sites are among the best places to find morels and boletes!

How Nature Adapts to Forest Fires

When gaps are opened in the canopy, some, like pine grass, gain access to more sunlight and respond by flowering. When brush is cleared from the understory and gaps of bare soil are opened up, plants like fireweed readily colonize them with their lightweight, wind disseminated seeds. And sometimes, fire changes the composition of the soil itself, volatilizing nitrogen and other nutrients. When this happens, plants (like lupines), that typically grow in nitrogen-deficient soils but are able to fix it, multiply quickly. Animals have some pretty amazing adaptations, too. In Australia, fire-foraging birds actively start fires to, literally, smoke out mammal and insect prey. These so-called fire hawks — black kites, whistling kites, and brown falcons — swipe burning sticks or grasses from fire areas (and sometimes even human cooking fires!) and drop them into unburned areas to set them alight. They are, of course, a notable exception. Most wildlife species will use intimate knowledge of their home ranges to run or fly away from fires. Those that aren’t as quick on their feet, like ground squirrels, frogs, and ants, will burrow deep underground or shelter underneath rocks and downed logs. Others will wait it out in nearby bodies of water, returning to assess damage and take advantage of newly-released nutrients and habitat layers once it's safe to do so.

No species is adapted to live in fire, but many have found ways to "rise from the ashes". Several species have adapted over thousands of years to the fire regime — or, fire frequency, intensity, and fuel consumption patterns — unique to their regions. But human activities such as fire suppression, land degradation, and settlement, are shifting the balance from normal, low-mid range fires that help keep ecosystems in balance to high-intensity blazes that destroy everything in their path. Some forest fires are so severe that nature isn't able to recover on its own. In other instances, only a lower-value bushland will appear where a healthy forest used to be. But that's where One Tree Planted comes in to plant trees and help catalyze the natural recovery process. Want to help us restore forests that have been destroyed by wildfires? Learn more about what we're doing to help and plant a tree for forest fire recovery today!