Could Climate Change Lead To The Extinction Of Bees?

Newsweek - Lisa Spear

A mason bee pollinates a flower. Scientists found that when they heated up the bees' environments, up to 70 percent of them died. Getty Images 

The survival of bees is hanging in the balance. Some species are dying off at a record pace, and toxic agricultural chemicals might be to blame. There seem to be many threats to these winged creatures, but climate change may be the final straw for some bee species. If the Earth continues to warm and bees don’t find a way to adapt, some populations could face extinction, according to new research.
A team of scientists found that 30 to 70 percent of mason bees died when they heated up the bees' environments. This reveals that if temperatures continue to climb, bee populations could begin to die off at faster rates, disrupting ecosystems worldwide, said Paul CaraDonna, an ecologist at Northwestern University.
“It was a pretty sobering result. This is not good news for this bee,” CaraDonna told Newsweek.
Over two years, CaraDonna led a team of researchers in Arizona’s Santa Catalina Mountains to simulate the impact of climate change on bees. They built 90 nest boxes, housing up to 15 bees each. The scientists painted some boxes with white reflective paint to simulate a cooler environment, similar to that of the 1950s. A second set of boxes were painted with a clear coating to act as a control for the experiment.
And a final set of boxes were painted black to simulate the future climate predicted for the years 2040 to 2099. By simply painting the boxes black, they absorbed more radiant energy, heating the box and the bees inside. The bees lived in the altered environments from early in larval development all the way through metamorphosis and into adulthood. The findings were published Thursday in Functional Ecology, the British Ecological Society’s journal.
“Almost no bees die when you have cool conditions or regular conditions, and quite a bit more die when you warm things up a couple of degrees on average,” CaraDonna said. “I was quite surprised in those years there were many bees that didn’t make it.”


The bees that survived the heat became smaller, lost much of their body fat and suffered from disruptions to their hibernation. These results suggest bees that survived were not healthy and might struggle to find food or a mate.
“Local bee populations could possibly go extinct in the future because of climate change,” said CaraDonna, who also works as a research scientist for the Chicago Botanic Garden, a conservation science center.
This species of mason bee, Osmia ribifloris, also called the “blueberry mason bee,” is native to the western United States and northern Mexico. This particular bee constructs nests inside of holes and cracks in dead tree stumps. As a primary pollinator of the flowering desert manzanita shrubs, this bee may have a big impact on its ecosystem.
“Native pollinators are a really important part of what makes nature run smoothly,” said CaraDonna. “It's estimated that close to 90 percent of all flowering plants benefit from animal pollination. That ends up at around more than 300,000 plant species worldwide.”
While the specific mason bees used in the experiment do not pollinate agricultural crops, it’s possible that the rising temperatures could also hurt other bee populations. Through a trickle-down effect, the die-off of bees could eventually disrupt human life by hurting our agricultural systems, said CaraDonna.
“You start tinkering with all these pieces, and there are many consequences that can start disrupting the function of natural ecosystems, and eventually that can cascade to affect humans as well,” he said.

Links

• Climate Change Could Drive Bees in Warmer Regions to Extinction
• Study Shows Future Climate Change Could Decrease Bee Population
• Bees are dying. What can we do about it?
• How Climate Change is Messing with Bees
• The buzz on climate change: It's bad for bees
• Save the Bees: EU to Ban World’s Most Common Pesticides