(CN) — Bee populations have been in decline since at least 2005 due to habitat loss, invasive species, pesticide use and climate change. Now, one of nature’s most important pollinators faces a new threat: fire season.
Out of nearly 4,000 bee species native to North America and Hawaii, close to one in four are already considered to be under threat, and ongoing wildfires are widely believed to be adding to their ordeal. Across the pond, new research out of Australia shows that the number of threatened bee species there is expected to increase almost five-fold after the country’s widespread Black Summer bushfires in 2019-2020.
Scientists from across Australia teamed up to investigate the impact that wildfires are having on bee populations in a new study published Thursday in the journal Global Change Biology. They found that increasing numbers of bee species can be classified as vulnerable or endangered as a direct result of the fires, fortunately the authors developed a new method for assessing some of the less famous species under threat.
“In Australia, we are seeing wildfires of unprecedented scale and intensity and these fires are predicted to get worse as our climate shifts further,” said Stefan Caddy-Retalic, an adjunct lecturer in the School of Biological Sciences at the University of Adelaide, and co-author of the study, in an email. “This work shows that our lesser-known species are just as vulnerable (and important) as more popular species like pandas and koalas. It also shows that it’s possible to use the data that we already have to predict how these catastrophic events might impact our native wildlife, and gives us enough evidence to act to protect vulnerable species and ecosystems.”
Unlike many North American forests, which often include a diverse range of tree species where bee populations have at times rebounded after fires, Australian forests tend to be dominated by eucalypts which take anywhere from several years to several decades to resume flowering. That means after a large fire there it can take considerably longer for flowering plants to coax back their bees.
The Australian Black Summer wildfires of 2019-2020 decimated 18.5 million hectares of countryside, an area roughly the size of Syria, killing 34 people and displacing around 3 billion animals. That kind of destruction is repeating itself across the globe of late, including regions of North and South America, Europe, the Congo and Asia, disrupting natural ecosystems on nearly every continent and leaving a marked impact on biodiversity and the population sizes of affected species.
“The Australian government needs to take real action to curb its extinction crisis,” said lead author James Dorey, a Flinders University PhD candidate and postdoctoral researcher at the Yale University Center for Biodiversity and Global Change, in an email. “There are 2,000 to 3,000 Australian native bee species in Australia and we could only analyse a small proportion of those due to data constraints. The government also needs to increase funding for museums (to digitise their collections) and provide funding for further sampling and research to be undertaken, and not just on bees but the many other poorly-understood taxa in Australia.”
The Australian government’s wildfire response has been largely focused on saving well-known, high-profile animals, Dorey contends, while lesser studied taxa get swept under the proverbial rug. He noted that him and his fellow authors found at least 11 Australian native bee species threatened with extinction under International Union for Conservation of Nature criteria. Prior to the Black Summer fires, only three Australian bee species were known to be threatened, according to the study.
Dorey’s team developed a new approach for making more rapid conservation assessments of poorly-understood species groups following destructive events such as wildfires, which he hopes other researchers will use and build on (the authors have made the tools freely available online).
“This kind of approach is novel and I would really like to see researchers of other groups make their own assessments,” Dorey said in an email. “I would also love to see scientists pick up the method and develop it further so that we can make the best conservation assessments possible.”
The increasingly short time periods between major fires are a growing concern as well, said the authors, because many species require long-unburnt vegetation to thrive, which becomes rarer by the year. They determined that species living in particularly narrow ranges – those that could be entirely wiped out by a single fire – face the greatest risk of extinction due to wildfires, along with species living in places especially ill-suited to fire, such as rainforest dwellers, and those that cannot easily migrate elsewhere.
“It’s not going to be easy, but policy-makers in Australia and around the world must really act on climate change,” Dorey concluded in an email. “We are already feeling the impacts of changing climates and things will only get worse if we don’t change the way that we deal with climate. On top of that, policy makers must act to curb other stressors such as habitat destruction, which still runs rampant in Australia. Hollow words are not enough and as a young researcher it is incredibly frustrating to see.”
Follow Dustin Manduffie on Twitter
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.