Boulder County ecosystems support an amazing variety of wild pollinator species
Pollinators are crucial to ecosystem health and human well-being, as they promote the reproduction of flowering plants, most of which are key food plants for both wild animals and humans.
Boulder County is exceptional in its abundance and diversity of pollinators. Bees are the most efficient insect pollinators, and our county has the highest documented bee diversity in Colorado, with 552 species! And although they are less efficient than bees, the more than 200 butterfly species in Boulder County also help to move pollen from flower to flower. This incredible diversity of bees and butterflies is likely due to the rich variety of ecosystems and flowering plants that occur along the sharp elevation gradient from the eastern plains to the western mountain peaks of Boulder County.
Recent research led by Dr. Seth Davis at Colorado State University provides the first description of wild bees in relation to Ponderosa pine forest management in Boulder County, connecting pollinator abundance and diversity to forest thinning treatments and fire disturbances. This study showed that bumblebees were the most common genus captured — in fact, 15 different bumblebee species alone were observed — and were present in high abundance throughout the growing season. Bees occurred similarly in Ponderosa pine forests that had been thinned for wildfire management as well as forests that had not been thinned. In fact, the researchers concluded that a variety of forest types translates into higher diversity of bee species.
“This study showed that if you want to have the greatest number of bee species and the greatest abundance of bees, then you need a mosaic of different habitat types. Where there’s a lot of downed wood, like you might find after a fire or a bark beetle outbreak, this is probably creating additional nesting habitat and refugia for bees.”
— Dr. Seth Davis, Colorado State University
(as quoted in the Longmont Times-Herald, 2019)
Davis’ study showed that Ponderosa pine forest stands on Boulder county public lands provide habitat for an incredibly rich native bee community and represent an important conservation resource. Managing the forests to promote a variety of forest types appears to be a great strategy for providing habitat for a high diversity of bee species.
But bees don’t just live in forests. Boulder County’s grasslands provide an abundance of plants that produce nectar and pollen that bees love. To add to these critical native grassland plant resources for bees, the city of Boulder has created the Boulder Pollinator Garden Project, which is designed to support and encourage Boulder residents to create their own high-quality pollinator habitat.
By planting a variety of flowering species in their yards and gardens, Boulder residents can create a sustained level of food resources for native bees throughout the growing season. Additionally, these pollinator-friendly gardens can create “pollinator pathways” that connect habitats in residential areas to the surrounding open space grasslands and forests. These efforts will help to provide local and regional environmental resources for bees and other pollinators, enhancing our biodiversity and ecosystem functions.
recommendations
Support pollinator communities through gardening and restoration efforts
Plant a pollinator garden
The city of Boulder’s Pollinator Garden Project provides resources for choosing appropriate plants for our semi-arid climate that will support a variety of bird, butterfly, and bee species that serve as pollinators. These flowering plants offer critical food resources for these pollinators. After you plant your pollinator garden, you can map it to add to the city’s list of gardens.
If you don’t have space to plant a pollinator garden, you can support pollinators in other ways!
Support organizations that focus on pollinator conservation, such as the Xerces’ Society’s Pollinator Conservation Program and the local Colorado Pollinator Network, which hosts an annual pollinator symposium. Purchase or build a nest structure for your residence that provides nesting habitat for native bees. And support forest management that enhances woody debris for cavity nesting bees.
resources:
Scott, V.A., J.S. Ascher, T. Griswold, and C.R. Nufio. 2011. The Bees of Colorado. Natural History Inventory of Colorado, University of Colorado Museum of Natural History, Boulder, CO.
Davis, T.S., R. Gelles, B. Kondratieff, and C. Stevens-Rumann. 2019. Effects of fire and thinning disturbances on biodiversity of wild bee communities in the Front Range of Colorado. Final Report to Boulder County Parks and Open Space and City of Boulder Open Spaces and Mountain Parks.
