Bees thrive in overlooked pockets of Puget Sound

(Press-News.org) PULLMAN, Wash. -- To the casual observer, it’s nothing more than an abandoned golf course.

But the land, along with other weedy, minimally maintained “marginal lands” in the Puget Sound area, is home to scores of wild bee species, including many never found before in Snohomish and King counties, according to a seven-year study by Washington State University researchers and others.

The survey of bees at three plots of land near airports and beneath power lines adds to the evidence that small corners of largely untended land can sustain bee populations amid the concrete and asphalt landscape of cities — even more effectively than parks and farms managed for hosting bees.

“Someone looking from the outside would say this is a junky old golf course that has been left to rot,” said David Crowder, a professor and researcher in WSU’s Department of Entomology who was the corresponding author of the new paper. “But it has 118 bee species in it, some that have never been seen before in our state.”

In fact, the marginal lands hosted significantly more bee species than diversified farms surveyed in recent years; other recent studies have found that urban “wastelands” such as vacant lots with wild flowering plants host larger bee populations than managed parks.

The study was published in the journal Ecology and Evolution. Co-authors included Riley Anderson, a postdoctoral researcher in Crowder’s lab, along with Will Peterman of Bee Search, a longtime bee enthusiast who has tracked bee populations in Western Washington for years, and the late Robert Redmond, a beekeeper who founded a non-profit dedicated to improving pollinator habitat, The Common Acre. Evan Sugden of Entomo-Logic, which specializes in the cultivation and supply of bees, was the lead author.

As concerns about bee populations grow, urban dwellers have undertaken a variety of approaches to help protect them, from pollinator gardens to municipal parks managed for bee populations. Until recent years, the marginal lands surveyed in the new study were largely overlooked as a resource.

“If you look across America, governments and municipalities own a lot of land that is not being developed but is minimally maintained — land around airports that can’t be developed because planes need to come in, land underneath power lines, easements along highways and roads,” said Crowder, who is also the director of WSU’s Decision Aid System, which provides information on pests and diseases to tree fruit and potato growers. “There’s always been a consideration: Should we develop that? Could we plant flowers in these types of habitats? How might we manage these types of habitats? Do we just let them go wild?”

The study originated in 2014. Members of nonprofit groups gathered samples using traps and netting at three sites in the Puget Sound region: two near airports, including the former golf course, and one beneath a power line. They returned monthly to gather samples between April and October for seven years. Overall, they collected more than 25,000 specimens representing 118 confirmed species. Other recent surveys of diversified farms have found just 75 species.

Individual sites in the new study hosted between 15 and 35 species in any given year. Nearly half of all specimens were of the globally common Halictidae family—ground-nesting species known as “sweat bees.”

The robust presence of diverse species is an important sign of ecological health.

“Different species do different jobs in the environment,” Crowder said. “If you have a diverse community of species, they’ll be pollinating plants throughout the year. If one species happens to be really harmed in any given year or goes extinct, there might be other species there that can fill in and do the same job.”

Few such bee surveys have been conducted in Western Washington. As public attention toward bees — and the threats to their survival — has grown, efforts to survey bee populations have increased across the world.

Those surveys are a crucial step to understanding what’s going on with bees, Crowder said. But it’s important to bring data from different surveys together to expand the picture of bee health.

“We can get something out of these individual studies but there’s a great opportunity for us to collate the data together at a big scale and learn about how bees are doing, where they’re doing well, where they’re not doing well,” Crowder said.

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