Pollinator species, including bees, are visibly diminishing in numbers around the world because of a variety of threats -- which poses a danger for humanity -- according to a new study. File Photo by Betty Shelton/Shutterstock
Aug. 16 (UPI) -- Scientists have unveiled the first-ever global risk index for pollinator species.
The new index -- published Monday in the journal Nature Ecology and Evolution -- not only forecasts what types of pollinator populations are declining and where, but also predicts how those declines will impact humanity.
Researchers pulled pollinator population data from a range of surveys and studies to detail declines across six geographical regions.
The data suggests important pollinators -- including bees, butterflies, wasps, beetles, bats, flies and hummingbirds -- are suffering worrying declines all over the world.
Roughly 75 percent of all crops and flowering plants rely on pollinators to reproduce. Declines in pollinators and pollination services could impact not only food production, but also the health of entire ecosystems.
A 2016 assessment by the Intergovernmental Science-Policy Platform on Diversity and Ecosystem Services said 40% of invertebrate pollinator species -- bats, birds, bees and butterflies among them -- were threatened on a local level.
Like the study published Monday, the 2016 assessment blamed these threats on land use, agricultural practice, pesticides and climate change, among other linked causes.
"What happens to pollinators could have huge knock-on effects for humanity," lead author Lynn Dicks said in a press release.
"These small creatures play central roles in the world's ecosystems, including many that humans and other animals rely on for nutrition. If they go, we may be in serious trouble," said Dicks, a zoologist at Cambridge University in England.
To build out the index, researchers also looked at the drivers of pollinator population declines.
The analysis showed habitat destruction remains the largest threat to pollinator species -- land management, including the expansion of monoculture farming and fertilizer use, is the second largest driver of pollinator losses.
Surprisingly, researchers determined pesticide use -- which often receives the most media attention -- is the third leading cause of pollinator declines.
Finally, the study suggests climate change is the fourth leading cause of pollinator losses.
If pollinator populations continue to decline, crop production could soon follow, the researchers predict.
"Crops dependent on pollinators fluctuate more in yield than, for example, cereals," Dicks said.
"Increasingly unusual climatic phenomena, such as extreme rainfall and temperature, are already affecting crops. Pollinator loss adds further instability -- it's the last thing people need," Dicks said.
Though ongoing declines in pollinator abundance and biodiversity are likely to have significant impacts on commercial agriculture, the researchers suggest pollinator losses could also impact human populations that rely wild plants and fruits, including populations in Africa, Asia-Pacific and Latin America.
Production of crops that rely on pollinators has increased 300 percent over the last half-century, leaving food systems increasingly vulnerable to pollinator declines.
According to the study, populations in China and India are especially reliant on pollinated fruits and vegetables.
The study's authors warn that there is still not enough population data for pollinators in the Global South, with the most robust data on pollinator declines coming out of Europe, where roughly a third of bee and butterfly species are declining.
"This study highlights just how much we still don't know about pollinator decline and the impacts this has on human societies, particularly in parts of the developing world," study co-author Tom Breeze said in the release.
"While we have data on how pollinators are doing in regions like Europe, there are significant knowledge gaps in many others. More research is needed on a global level so we can really understand the problems we face, and how we might address them," said Breeze, an ecological economics research fellow at the University of Reading in England.