PhD student’s research investigates native bee habitats in urban areas

By Meghan Chua

While pollination ecologists around the world study how declines in habitat and emerging diseases affect bees, researcher Vera Pfeiffer is looking for attributes of systems that can sustain these and other native pollinators in places with a large human footprint.

Vera Pfeiffer catching bumblebees
PhD student Vera Pfeiffer catches bumblebees with a hand net in Madison, Wisconsin. She is currently conducting a survey of native bees in and around Madison to determine what aspects of the habitat support an abundance of native pollinators. Photo courtesy of Vera Pfeiffer.

“There’s evidence that cities can support very diverse pollinators,” said Pfeiffer, a PhD student in the Nelson Institute for Environmental Studies’ Landscape Conservation Lab at UW–Madison.

Pfeiffer studies how features of the landscape influence pollinator movement and population density. One of her current research projects is a survey of native bees around Madison that investigates what aspects of habitat help boost the presence and abundance of native pollinators. Since most native bees in the Madison area are ground-nesting, undisturbed portions of soil can support pollinator biodiversity in urban or agricultural areas.

Bumblebees are important native pollinators that are found all over the world. They carry large amounts of pollen and can use their flight muscles to vibrate flowers, releasing extra pollen through this buzz-pollination.

Pfeiffer’s survey of Madison’s native bee communities will also help her analyze how pollinators’ foraging areas change across different urban landscapes in and around Madison. Bumblebees can fly longer distances to forage than many smaller native bees, yet studies have shown they may be particularly sensitive to urbanization.

Pfeiffer began researching pollinators as a master’s student at Oregon State University, where she studied plant-pollinator interactions in meadows. She later spent a year studying bumblebee foraging practices across agricultural landscapes in the Czech Republic through a Fulbright research fellowship.

In another project with Dr. Janet Silbernagel’s Landscape Conservation Lab, Pfeiffer studied bumblebee foraging in the cranberry fields of central Wisconsin. Cranberries are a mass-blooming crop, providing abundant flowers for pollinators for a short time each season.

Vera Pfeiffer in the Central Oregonn Cascade Mountains
Pfeiffer at the H.J. Andrews Long-Term Ecological Research Forest in the Central Oregon Cascade Mountains where she conducted her master’s research. Photo courtesy of Vera Pfeiffer.

Using DNA samples from bumblebees taken before, during, and after the cranberry bloom, Pfeiffer estimated colony density and analyzed how bumblebee foraging changes based on the time of the season and abundance of flowers. Understanding the patterns in landscapes helps researchers understand which mechanisms are more influential at different times and places.

“I think that broader, pattern-oriented approaches can be useful to get a feel for what’s important in our world today,” she said.

In surveying Madison’s native bee populations, Pfeiffer hopes to provide a better, more informed context for policies that can make the habitats we share with pollinators more biodiverse.

“Conducting research that allows us to better understand native bee populations and what limits them will help us support them better and conserve and restore their habitat within even very modified ecosystems, like agricultural and urban systems, where we have a very heavy footprint,” she said.

Pfeiffer is taking a step toward sharing her expertise with policymakers as a recipient of the Ecological Society of America’s 2018 Graduate Student Policy Award. Through the award, she will travel to Washington, D.C., in April to learn from ecologists who work in federal agencies. She will also meet with members of Congress to discuss the importance of federal funding for the biological and ecological sciences.