The climate crisis could lead to more small-bodied bees but fewer bumblebees, according to research warning of potential “cascading” effects on plant pollination and across whole ecosystems, reported The Guardian.
Scientists in the US studied more than 20,000 bees over eight years in an area of the Rocky Mountains to find out how different types reacted to changing climatic conditions.
In research published on Wednesday in the journal Proceedings of the Royal Society B, the authors said that while environmental conditions varied from year to year, the sub-alpine region from which they took samples was “particularly vulnerable to climate change”, with generally warming spring temperatures and earlier snow melt. They found that larger-bodied bees and comb-building cavity nesters declined in abundance as temperatures increased, while smaller, soil-nesting bees increased.
“Our research suggests that climate-induced changes in temperature, snowpack and summer precipitation may drastically reshape bee communities,” the authors said.
Researchers said the findings suggested a reduction of bigger bees, including in the families of bumblebee, leafcutters and mason bees, with higher temperatures.
Declines were particularly marked for bumblebees, which the researchers suggested “this group is more threatened under climate warming than other bees in our system”.
That tallies with other studies showing that bumblebees, the dominant pollinators in many ecosystems, have a lower heat tolerance than other bees and move to cooler regions at higher altitudes as temperatures warm.