This tiger swallowtail butterfly is a pollinator that could benefit from a little more green space.
Jim, the Photographer
When we think about improving urban food systems, we tend think about growing more vegetables — densely planted backyard plots and community gardens, with tiny tomatoes ripening in the sun. But according to some experts, we should start thinking smaller — way smaller — as in bugs.
According to the United States Forest Service, over 80 percent of flowering plants depend on an animal to help them pollinate. These pollinators take a variety of forms — from hummingbirds to bats to lemurs — but the bulk of them are insects. Butterflies, beetles, and, most importantly, bees. So if you like to eat, you need to take care of your pollinating insects.
Seattle artist Sarah Bergmann first got interested in pollination a few years ago, after hearing how colony collapse disorder was destroying honeybee populations. Bergmann was surprised to learn that honeybees aren't a native species — historians believe they came over with the Jamestown colonists. And, Bergmann discovered that there are actually a host of native pollinators, from the tiny Orchard Mason bee to the dramatically colored swallowtail butterfly. And they all face a host of problems, from being threatened by pesticides to seeing the flowers they feed on (and pollinate) disappear due to urbanization or monoculture. And so Bergmann came up with a solution for Seattle: The Pollinator Pathway.
The Pollinator Pathway turns parking strips into a corridor of flowers to span green spaces in the city, serving as a thoroughfare for pollinators to get from one area to another. Bergmann began several years ago, working with landscape architects, entomologists, and the city itself. Homeowners volunteer their planting strips, and groups of volunteers lay down sheet mulching, then plant a careful assortment of low-maintenance native plants and flowers, designed to provide a long-lasting source of food for native pollinators while meeting city planting requirements. "The goal is to support the native ecology, which supports the pollinators," Bergmann says.
But while a corridor of native flowering plants is undeniably beautiful, can it really make a difference in the ecology and food systems of an urban environment?
Scott Black is executive director of the Xerces Society, a nonprofit organization dedicated to invertebrate conservation. He spends most of his time working on pollination problems in large agricultural landscapes, where the monoculture practice of planting acres upon acres with a single crop can devastate the flower population just as much as urban paving.
Black says that even though the scale is smaller, ideas like the Pollinator Pathway can make a difference. "These projects are creating diverse patches which helps pollinators locally. And the more we have, the more resilient they'll be to all the issues we face, from habitat loss to pesticides."
Black also says that the idea that connecting populations can help them is actually an established one in biology: it comes from the study of island biogeography. "There's lots of science behind the idea of corridors," Black explains. "The more disconnected your populations are from each other, the less likely they are to survive. Populations in isolation don't often have the resilience that connected populations do. So if you can have 'stepping stones' connecting habitats, that'll benefit the pollinators."
Black also jokes that the fact that pollinators can fly makes corridors easier. Unlike rivers, pollinator corridors don't have to be continuous, so a few gaps here and there will be fine. Although, he points out, closer is better.
Bergmann's ideal would be to span the city, connecting green areas everywhere with pathways that strengthen pollinators for food systems in the city and beyond. By this fall, she hopes to be a third of the way to her goal — with 20 of the 60 stretches she's targeted transformed from grass to garden.
But, like Black, she notes that you don't need a full corridor to make a difference — every parking strip takeover, every time someone plants a native flower instead of an imported petunia, is one more small victory for the pollinators.