Montrose Point Park in Chicago appears to be a tiny area of green surrounded by miles of urban and suburban sprawl. Thus it doesn’t seem to be a pollinator haven. Doing so is Medewin National Tall Grass Prairie, a protected and restored preserve located more than fifty miles from the city’s pollution and activity.
When scientist Rebecca Tonietto investigated the wild bee groups in both locations, she was shocked to find that bees and species variety were nearly comparable. The native bees thrived in both the urban park and the natural setting.
Was there something wrong with the prairie restoration, she wondered? Was there something special about Montrose Park? Tonietto says, “Spoiler alert: that was it.”
“It’s a perfect site for bees as long as there’s stuff to eat, a nesting location for the bees, and a partner within flight range,” Tonietto explains. She is currently a biologist at the University of Michigan-Flint, where she researches urban pollinator habitats more than ten years after her Chicago research.
Tonietto’s discoveries were unexpected at the time, but they weren’t a fluke. According to a growing body of study, pollinator groups, particularly native bees, may fare better in cities than in the countryside. According to studies from across the world, bee populations and species variety are higher in specific urban locations than in more rural settings characterized by intense agriculture.
According to a recent study of UK cities, one probable explanation is that urban locations can provide a more diversified nectar selection than rural or natural regions, with a wider variety of flowering plants giving a consistent supply of nectar sugar an essential food source for bees. Perhaps more surprisingly, the researchers discovered that non-native plants, which accounted for more than 80% of all garden plants studied, provided a significant percentage of the nectar supplies.
The new study’s findings include a subliminal message that some environmentalists and scholars fear may be misconstrued by the general public. They argue that native bees visit exotic garden flowers doesn’t imply we should cultivate non-native plants indiscriminately or encourage additional species invasion. And just because cities can provide unexpectedly excellent bee habitat does not negate the need for conserved, undeveloped places for conservation. “Cities, of course, aren’t ideal. There are numerous environmental concerns for bees, not only bees but also plants,” says Panagiotis Theodorou, a community and evolutionary ecologist at Martin Luther University in Halle, Germany.
Though, the overall message is upbeat: home gardeners can make a significant difference for wild bees and other endangered pollinators. “The activities of individuals who may believe they cannot make a difference in terms of environmental protection, they do matter,” says Nick Tew, principal author of the new UK study and a PhD student in urban ecology and conservation at the University of Bristol. “It will make a huge impact if a lot more people get on board and plant their gardens to be more pollinator-friendly.”
Insect populations, particularly crucial pollinators such as bees and wasps, have been declining for decades, posing a danger to ecosystems and the global food supply. To yield seeds and fruit, most blooming plants and commercial crops like blueberries, cherries, apples, and almonds require strong pollinator populations.
Pesticide usage, habitat loss, climate change, and pollution are all factors contributing to insect reduction. However, including city habitats in the conservation toolkit might aid bee pollinators in surviving in an increasingly human-dominated world.
Plant diversity, not simply nectar abundance, is required for a thriving bee colony. Bees, like us, need a diverse nutritional diet, according to Sara Leonhardt, a biologist at the Technical University of Munich in Germany who studies plant-insect interactions. Because bees require food throughout the spring, summer, and fall, timing is critical since plants blossom at various periods of the year. According to Leonhardt, the optimal pollinator habitat delivers different blooms over a long period.
According to new study from the United Kingdom, urban, rural, and conserved environments all supply roughly the same amount of nectar resources per unit area to bees. Nectar sources in cities, on the other hand, were made up of nearly twice as many different plants. Home gardens, not parks, provided most nectar and plant variety, accounting for over 85% of all nectar sugar in cities.
Tew’s study only looked at plants, not the number of pollinators that visited them, but other recent research has indicated that cities have more bee species than surrounding areas. For example, an investigation led by Theodorou in 2020 discovered more bee species in German towns than in surrounding rural regions.
Even though agricultural land dominates most of the rural environment, according to Theodorou, well-kept yards, communal gardens, and parks produce more flower species. He says that there is a boom-and-bust cycle in agriculture. For a brief time, there may be a lot of one sort of resource—for example, flowering canola fields in Germany—but “then you have nothing,” adds Theodorou.
That doesn’t imply that gardeners’ favorite non-native plants are always as pollinator-friendly as native plants. Theodorou remains a strong supporter of native species versus non-natives. He points out that certain popular decorative plants, such as petunias, are cultivated primarily for human aesthetics and do not supply any nectar to pollinators.
Wild bees, on the other hand, prefer non-native species to be indigenous in some situations. Researchers in Beltsville, Maryland, discovered that a plot of mixed, carefully selected non-native flowers attracted more native bees and species than a plot of native flowers in a study published in 2020. 11 of the 120 bee species observed by the researchers were only found on native flowers, while 23 were only found on non-native blooms. The study’s lead author, Nicola Seitz, a scientific advisor at the Senckenberg Institute in Frankfurt, Germany, emphasizes that her findings do not imply that non-native flowers should be planted everywhere. “When utilizing non-native plants, we must constantly be cautious since they may upset local plant communities.”
However, many individuals live in habitats that have already been transformed to where a garden of purely native plants may not be feasible—or even desirable—if pollinators are the aim. Seitz, for example, claims that the soil at her Beltsville research location was highly sandy, allowing just a few native species to survive. That sandy meadow may border a forest in an undeveloped Maryland, providing a varied selection of native flowers for bees to pick from. But, as Seitz points out, “we don’t have our natural environments in the same way that we used to.” “Having intact natural landscapes and ecosystems with an abundance of all of those native species would be ideal, but we just don’t have them,” she adds. “We need to think about other options.”
There’s also something more to consider: home gardens aren’t simply for pollinators; they’re also for people. Tonietto from Michigan says, “I don’t want to criticize someone’s garden.” “I’d like to honor their garden. Plus, there’s always more. And a few locals per year would be fantastic,” she says. However, chastising gardeners for planting non-native species isn’t always practical, especially since native plants are sometimes more expensive and difficult to locate than attractive non-native plants.
Tonietto’s current research in Flint, Michigan, combines the advantages of gardening for humans and bees. Megan Heyza, a local homeowner, launched the Porch Project to foster a feeling of community by repairing and decorating people’s front porches. When Tonietto learned about Heyza’s purpose, she sought a grant to supplement the project’s landscaping funding. Since then, Tonietto and her crew have planted roughly 30 gardens on Flint’s east side. The researchers meet with each homeowner before planting native or non-native ornamentals in their gardens. The team then returns regularly to each location to survey the bees and other pollinators. Early findings suggest that native bees visit native and non-native gardens and that pollinator diversity is influenced by factors other than plant species, such as the quantity of sunlight a garden receives.
“It’s fantastic if someone’s favorite plants are [ornamental] roses, and they want to have roses in their yard. Tonietto responds, “You should, and that’s OK.” She has several non-native plants flourishing in her garden and her native, Midwestern prairie wildflowers. Some lilies she transplanted from a former family house are a particular favorite.
She repeats, “Better is better.” Pollinator habitat spans a wide range of conditions. Gardening may always be bettered, but even small initiatives toward increasing biodiversity should be applauded. She believes that having a variety of flowers is preferable to have a few and that any flowers are preferable to none.
