The growing number of gardeners growing pollinator gardens may need to dive a bit deeper than the selection of plants they choose to place in those beds. While many are concerned about butterflies, it likely will be the bees that make or break the wildflower ecosystem they are trying to create.
There are hundreds more species of bee than most of us realize and they are all critical to maintaining wild plant communities, according to a study by scientists at Rutgers University.
While previous research tended to focus on just one or a few dominant species of bees, the Rutgers team concluded that ecosystems rely on many bee species to flourish and not just a few dominant ones.
Their results support the fundamental idea that biodiversity is key to sustaining life on Earth, notably in an era when species are rapidly going extinct due to pressures from climate change and human development.
“This is one of the strongest demonstrations to date of the importance of bee diversity, and of rare bee species, for maintaining healthy ecosystems,” said Dylan Simpson, the author and a doctoral candidate in Rutgers’ Graduate Program in Ecology and Evolution.
“This matters because pollination is critical for plant reproduction. And life on land depends ultimately on plants.”
The researchers looked at bees visiting flowers in 10 wild settings and one experimental garden of native plant species in New Jersey. They directly observed bee-plant interactions, identified bee species and the visited flower’s species, and tracked the frequency of interaction between specific species of bees and plants.
There are about 400 species of bees in New Jersey, some familiar like the common eastern bumble bee, but others rarely seen.
“There are many more bees than you realize,” Simpson said. “A lot are small, some are metallic and shiny, some are dark, not striped, and inconspicuous.”
While observations were made in open, meadow habitats, observed bee species included those associated with both forests and human-dominated habitats.
The pollinated plants included black-eyed Susan, bee balm, goldenrod, New England aster, milkweed, white clover, red clover and others.
The researchers found that different bee species are often important to different plant species. While just a few bee species are important to any particular plant species, the number of bee species necessary to support a large plant community must be equally large.
A substantial portion of the bees that pollinated plants were rare species.
Much of previous research has typically focused on single-species crops and concluded that pollination often depends on a few common bees.
“In contrast, this study focused on a much wider variety of plants and found that even rare bees can be important to particular plants,” Simpson said.
“These results suggest that ecologists have likely underestimated the importance of bee diversity for pollination in diverse, natural ecosystems.”
Contact Marcus Schneck at mschneck@pennlive.com.