Berkeleyan

Bee garden in BerkeleyInspecting Gordon Frankie's Oxford Street bee garden are Frankie (far left), Berkeley bee researchers Rollin Coville, Sara Witt, and Jaime Pawelek, and an unidentified visitor. Identifying common garden plants attractive to native bees is a key focus of Frankie's research.

A must-see spot — if you're a Berkeley bee

Gordon Frankie's Oxford Street garden is a popular stop for dozens of native bee species — and a laboratory for learning what plants they prefer

| 01 May 2009

Bees here now

The Urban Bee Garden's website, maintained by Gordon Frankie's research group, is a rich source of information for those who would like to adapt their home gardens to be more attractive to native bees and other wildlife. Happily, you'll learn, the same flora frequently do double-duty in this effort: The sunflowers you plant to provide seed for a bird feeder, for example, also provide bees with a source of nectar and pollen, while various species of Eriogonum (buckwheat) are attractive to beneficial flies and wasps. Information on the site ranges from seasonal lists of bee-attracting plants to a primer on bee behavior and the impact of garden mulch on bee-nesting behaviors (hint: it's negative). Would-bee (sorry…) researchers will also find detailed instructions for data collection: Requirements include a stopwatch, a notepad, and the desire and ability to stand still and count bees.

The native-bee garden maintained by Frankie's group is open to visitors one day each year, as a stop on the Bringing Back the Natives Garden Tour, which this year takes place on Sunday, May 3, from 10 a.m. to 5 p.m. More than 50 gardens in Alameda and Contra Costa counties participate; most are private home gardens, but some are larger, such as the East Bay Regional Parks' Botanic Garden in Tilden Park and Frankie's research garden in Berkeley. For information, visit www.bringingbackthenatives.net; though the self-guided tour is free, registration is required at one of several participating gardens in East Bay cities on the day of the tour.  

Gordon Frankie is one of many conservationists who believe that cities don't have to be sterile and low in biodiversity, but can provide significant relief to some native or endangered species — in this case, bees. As any urban gardener knows, bees will flock to certain flowers, whether they're wild or cultivated by human hands.

Frankie, a professor and research entomologist in the College of Natural Resources, wants to know which of these flowers are most effective at attracting bees. His group runs a constant taste test in his Oxford Street research garden, which sits between busy streets at the western edge of the Berkeley campus, fringed by parked cars and apartment buildings. The researchers monitor bee activity on different flowers to see which are the most popular; they also study the habits of bees in urban gardens around California. Frankie is keen to disseminate his research to the public as it happens: He wants gardeners to use what he's learned to help keep bees thriving in Berkeley and other cities.

In the late 1980s, Frankie began monitoring native bees in northern California to get a baseline before the potential arrival of the Africanized honeybee, a hybrid strain known to wipe out native species. Years later, his group added a research site in Albany Hill Park in Albany. The bees they saw there led Frankie to wonder about the bee populations of other Bay Area cities, and in 2001 he and his colleagues began monitoring bees in residential gardens in North Berkeley. Frankie was so excited by the numbers of native bees in urban gardens that he decided to start a research garden to directly test the attractiveness to bees of common garden plants. In 2003, the first plants went into the bare-dirt research tract on Oxford Street.

Buzz-bee, Berkeley

The garden and greenhouse facilities allow Frankie to more precisely evalluate the tastes of Berkeley bees. He and his group plant flowers in different combinations and arrangements, to get a better idea of the lure of one specific type, rather than of the particular combination of plants that a gardener happened to choose.

To study the bees, the researchers watch a five-foot-square plot with one kind of plant in it, start a three-minute stopwatch, and look for bees making contact with the flowers' centers, where the pollen and nectar are. They identify bee types "on the wing" as best they can, based on their size, flying pattern, appearance, and foraging patterns. To an untrained eye, the different yellow and black blobs zipping around the plants seem virtually identical, but Frankie's researchers can differentiate many families (genera) of bee as they dart by. They capture some bees in nets and send them to Professor Emeritus of Entomology Robbin Thorp at UC Davis for exact species identification.

Frankie and his research group have monitored bees on approximately 1,000 different garden plants; they found 130 that are attractive to bees, and another 70 that are moderately attractive. Most of these plants are non-native, since the majority of gardens in California (and the U.S.) contain exotic plants. "Native bees like native plants, if they have the choice," Frankie says. "But exotics can be a very good food source for them, too."

Some of the common garden plants they've found that are attractive to bees include cosmos, which boasts large pink and white flowers; different kinds of sage (salvias); and purple tansy, a California native that Frankie loves because of its bright purple pollen — easily visible in clumps on bees' legs after they've been foraging.

Over the years, Frankie and his group have found 84 different bee species in Berkeley alone. He suspects there are really more like 95 to 100 species in the city. (California contains more than 1,600 different bee species.) "Every time we go out, we find another one," Frankie says. Most of the species found in Berkeley are native to the area.

Even among the 84 Berkeley bees, there's surprising diversity. The squash bee frequents only squash flowers, and is usually around at sunrise. (Last summer, Frankie and his group planted rows of squash plants to attract this particular bee, taking home armfuls of zucchini and summer squash as lagniappe.) The leafcutter bee slices out pieces of leaves to use for its nest building. The green sweat bee's body is a brilliant metallic-green with black stripes on its abdomen; in some climes (though not here), it is attracted to salty human perspiration. And then there's the headbonker bee, so named because the males of this species have a habit of charging and head-butting other bees that come too close. (A few researchers in Frankie's group have been at the receiving end of a "head bonk.")

More to the story

Although Frankie and other conservation biologists are concerned about the survival of native species on their own merits, native bees are also important for plant life, including crops. Female bees collect pollen to bring back to their nests to feed the young and, while flying from flower to flower, drop some of the pollen grains onto other flowers, thus fertilizing them.

Honeybees are generally the primary crop pollinator, though research by Claire Kremen, assistant professor of conservation biology at Berkeley, shows that California wild bees help honeybees pollinate. (Their pollination efficiency increases fivefold in the case of sunflowers.) Frankie and Kremen realized that many of the native bees important for crop pollination were the same bees frequenting urban gardens. "We really started this project out of curiosity, but soon started to realize that there was more to the story," Frankie says.

The survival of native bees and their supporting role as crop pollinators may be especially important now, as honeybees have been mysteriously dying recently due to the poorly understood "colony collapse disorder." Even in our own front yards, bees are important for pollination of many garden plants. Amateur gardeners may find that planting to attract bees improves the overall health of their garden. "Some people want to keep their gardens sterile and free of insects, but that's just not realistic," Frankie says. "Gardens have bees in them."

Getting the buzz out

Frankie's group wants to get its message directly to the interested public. Frankie and other researchers in his group — in particular, his current research assistant, Jaime Pawelek — have been involved in community-outreach programs, mainly with local schools, for the past decade. Over the last few years they've been working with community members interested in planting bee-friendly gardens, both on private land and in public areas.

"We've been approached by nurseries, schools, gardeners, and even landscape architects," Frankie says. His lectures are often requested by local gardening groups, and the group's research garden is a stop on the yearly Bringing Back the Natives Garden Tour, a spring tour of public and private Bay Area gardens with a special focus on native plants. That tour is the only time the research garden is open to the public (see box at left).

Frankie's group also maintains Urban Bee Gardens, a popular website aimed at interested gardeners (see box), and is working on a book about urban bee gardening to be published by UC Press next year.

Jennifer Hernandez, a graduate student in Frankie's group, has taught kids in public schools through a program called "Explor-ing California Biodiversity," orga-nized by UC Berkeley and the Berkeley Natural History Museums consortium. She uses her background in bee research to teach children about how scientists classify organisms, how bees and other animals pollinate plants, and how insects develop, among other lessons. The students learn to trap and identify different bees. "It's a great way for them to learn about the diversity around them," Hernandez says.

Rachel Tompa, a former Public Affairs intern, is a science writer living in Seattle.