Prescribed Burns
Are The Wildfires Good For The Environment?
Some landscapes evolved with periodic wildfires as an influential force, and people have been using “prescribed burns” (the controlled application of fire under specified weather conditions) to restore health to certain types of ecosystems for millennia. But while some fires in some places might be beneficial, the wholesale torching of the forests of the American West right now is far from beneficial overall—not to mention a sure sign that our profligate ways with carbon emissions are coming back to haunt us.
On the plus side, forest fire does clear away the tinder-like overgrown understory that has resulted from years of forest management that avoided fire at all cost. Hundreds of years ago, many of the forests now on fire in California, Oregon and Washington had fewer yet larger and healthier trees. But these days, partly thanks to fire suppression regimes as well as other factors, forests are more crowded today with smaller, less healthy trees. It’s also harder for those remaining mature, established trees to compete for nutrients and space with all the undergrowth that’s built up in recent decades. In these situations, small manageable fires (or even better, prescribed burns) cannot only be beneficial, but can help prevent larger fires down the road by clearing the weaker, smaller trees.
Another benefit of wildfire is the clearing of overgrown underbrush to make room for new grasses, herbs and regenerated shrubs that provide food and habitat for many wildlife species. Also, the removal of thick stands of shrubs increases the water supply for the remaining larger plants and trees—and also allows streams and rivers to swell, further benefiting ever-thirsty native flora and fauna.
Yet another benefit of fire is that it kills off fungi, bacteria, viruses and insects that can decimate tree and plant communities and entire forest ecosystems. According to CalFire, California’s statewide wildfire management agency, more trees die from insect infestation and disease than from wildfire; some fire actually helps keep forests devoid of such pests and healthier overall than without fire. CalFire points out that vegetation burned by wildfire provides a rich source of nutrients that nourish surviving trees and soil.
Some landscapes need occasional forest fires to germinate seeds for new plants’ growth. Credit: Richard Droker, FlickrCC.
And periodic fire can be an important way to keep certain ecosystems in balance. Many trees have evolved with fire and some even require it for seed germination; a few species even sport leaves covered with flammable resins (manzanita, scrub oak, chamise) to encourage fires that help seed the next generation.
National Geographic reports that, surprisingly, wildlife casualties tend to be low during wildfire events, as animals—especially those native to the areas on-fire and evolved to respond to the threat—either burrow in the ground or flee to safer areas instinctively. But invasive plants and animals may not fare as well given lack of genetic imprinting to be on alert for the threat.
Once the smoke clears on 2020’s horrific fire season, mass human and wildlife casualties could be the new normal. Global warming certainly has thrown the fire season into overdrive this year across California, Oregon and Washington, whether or not the Trump administration cares to admit it.
CONTACTS
CalFire | “The Ecological Benefits of Fire”
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