The risks that come with farming can make playing the stock market seem tame. A hail storm, unexpected drought or flutter in the price of fertilizer can make the difference between a profitable year and ruin.
Financial whizzes recommend investing in a diverse range of stocks to guard against market gyrations. Farmers, too, can benefit from diversity, say scientists. But this kind comes on the wing.
While most people might associate domesticated honeybees with pollination of farm fields, it turns out dozens of wild bees can visit the flowers of a single crop. And new research tracking fields of watermelons and blueberries over several years suggests that a one-time snapshot of bees frequenting a field underestimates the variety of species needed to ensure a good crop.
“You do actually need more bee species in order to get stable pollination services over a growing season and over years,” said Natalie Lemanski, a postdoctoral researcher at Rutgers University who helped lead the work.
There is a growing appreciation for the importance of all kinds of diversity in ecosystems. Genetic diversity within a species helps ensure organisms can adapt to changes in their surroundings and reduces the risk of inbreeding, a problem for endangered species. Habitat diversity can increase the odds that a species will find a place to thrive. Taking a cue from the financial sector, salmon researchers in Alaska dubbed this the “portfolio effect” after finding that a key to the robust sockeye salmon runs of Bristol Bay was the myriad small rivers lacing the region.
But when it comes to pollinators and crops, the effects of diversity have been less evident. In part, that’s because at any given moment, a flowering field might be dominated by just a handful of these creatures. But Lemanski and collaborators at Rutgers and the University of California at Davis wanted to see if that picture changed when they expanded the view to encompass peek blooming seasons over several years.
To get this longer view, the scientists repeatedly visited 77 blueberry and watermelon farms in New Jersey and California over six years. With each visit, they netted all the bees targeting crop flowers in designated parts of a field. They counted which species were present and in what numbers. All told, they found more than 70 different wild bees. 09-21-22