Fire is a natural part of forest ecology in the western U.S., co-author Andrew Stillman at the University of Connecticut explained to Newsweek. But as megafires—large, severe wildfires spanning at least 10,000 hectares—are increasingly common in the U.S., scientists are trying to understand the ecological impact of these blazes, and predict whether they will become a natural part of forests or have unexpected negative effects on flora and fauna.
Over a period of eight years, researchers at the University of Connecticut, the Institute for Bird Populations and the U.S. Forest Service collected data on 118 nests in the parameters of six large wildfires in the Plumas and Lassen National Forests.
The woodpeckers were found to choose to nest in sites closer to the edges of “high severity” burn patches, where all or nearly all of the trees died in a fire, according to the authors of the study published in the journal The Condor: Ornithological Applications.
“The finding that the woodpeckers in our study tended to select nest sites closer to the edges of high severity burn patches provides added evidence that pyrodiversity [or having a range in the age, size and severity of burned patches in trees] benefits this species,” said Stillman.
The team thought the megafires might benefit the woodpecker, as the animals are linked with high severity areas where there are a lot of dead trees ready for nesting opportunities, Stillman said.
“However, it seems that the landscapes created by extra large, intense mega-fires are too extreme,” he argued. “Even fire-associated species need variation in habitat and access to both live and dead trees.”
“However, our research also demonstrates that areas which burned at a mix of different severities (considered ’natural fires’) can have numerous benefits to wildlife,” Stillman said.
As mega-fires become the “new norm” in some western U.S. forests, the team predicts there will be less and less pyrodiversity, and more threats to forest wildlife.
To conduct their study on the “elusive” species, Stillman and colleagues from The Institute for Bird Populations and the U.S. Forest Service, had to overcome a number of challenges.
“We drove endless networks of unmaintained roads, battled up steep slopes, and hiked up to 10 miles off-trail each day. In three years of research alone, my crew and I had to change 19 flat tires,” Stillman said.
The researchers acknowledged the study was limited because their work was on 118 nests in one region. Next, the team hopes to look at other regions in the western U.S. and forest fires with different characteristics.
Asked if climate change is partly to blame for the new intensity of the wildfires, Stillman said it is “one of a myriad of factors that are contributing to the concerning trends we see in wildfire size and severity.”
Prolonged droughts, increase in spring and summer temperatures, snow melting earlier, changing rain patterns, and a history of fire suppression contribute to the trend, he added.
