A new U.S. Geological Survey report released Tuesday suggests waterfowl throughout the boreal forest of North America are largely resilient to repeated forest fires. The study found that forest fires had no detectable impact on waterfowl abundance over timeframes extending from years to decades following the fire. Likewise, the extent of the fire, in terms of landscape burned, had no influence on their breeding abundance from the pre- to post-fire period.
“This is a positive result for waterfowl in the boreal forest given the high potential for increased fires in the future,” said Tyler Lewis with the USGS and lead author of the new study.
The western boreal forest is North America’s largest biome, encompassing more than 600 million hectares of largely intact forest that spans from interior Alaska through central Canada. Summer temperatures in the boreal forest have increased by at least twice the global average warming, and these temperature increases are linked to increased frequency and size of wildfires in the region.
The study uses a dataset spanning 60 years and covering a vast area across North America to provide the first in-depth evaluation of fire impacts on waterfowl abundance. The region examined includes the western boreal forest of North America that is recognized as an internationally important breeding area for numerous bird species.
This study builds on a report published by USGS in 2014 describing the resilience of a small-scale boreal lake ecosystem in Alaska to forest fires. That study similarly concluded that lake ecosystems were largely resilient to forest fires and that this resilience affected portions of the food web, from nutrient levels, to invertebrates, and up to water birds.
The new study provides the first known evaluation of fire impacts on waterfowl abundance across the western boreal forest of North America. From 1955–2014, over 1100 fires in the region burned waterfowl habitats surveyed by the Waterfowl Breeding Population and Habitat Survey (see map figure below), a cooperative survey annually conducted by the U.S. Fish and Wildlife Service and the Canadian Wildlife Service. Nonetheless, the study found that fires had no detectable impact on waterfowl abundance.
“These results suggest that waterfowl populations in the western boreal forest are resilient to forest fires and that current policies of limited fire suppression have not been detrimental to waterfowl populations,” said Lewis.