How Urban Centers Are Saving Bees
Urban centers are hot spots for native bee populations.
I recently discovered how urban centers are hot spots for native bee populations at the People & Pollinators Action Network (PPAN) Annual Pollinator Summit in Denver. Most of this information was presented at the summit by Harland Patch, Ph.D., author of The Lives of Bees.
Thanks to research conducted by Dr. Harland Patch at Penn State Center for Pollinator Research, his work is shedding light on the role of urban landscapes in bee conservation efforts. Despite the common misconception that bees thrive primarily in rural areas, the truth is that urban environments, such as city allotments and gardens, play a significant role in supporting bee populations.
In today's industrialized farming practices, rural areas often lack the necessary habitat and resources to sustain healthy bee populations. This poses a dilemma, as bees and other pollinators are essential for the pollination of farm crops. This paradox underscores the critical need for alternative habitats where native bees can thrive. Urban gardens offer a promising solution.
Bee support in urban allotments
In addition to agricultural practices, the rise in land development and suburban landscapes with conventional yards have lowered pollinator populations. However, Dr. Patch found that urban allotments with the most robust gardens full of biodiversity had the highest native bee communities. Generalist bees are the most abundant in urban gardens due to their ability to forage on a wide variety of flowering pollinators. They forage more freely and for a longer period of time than specialized bees.
He also discovered that large native habitat areas surrounded by suburban sprawl may actually increase species richness and species density over that of continuous grassland. This is accomplished by habitat complementation or supplementation. In other words, what you do in your landscape matters and makes a huge impact supporting native bee populations.
Native ground nester
Bumble bees, one of the key pollinators, actively forage for optimal nutrition. Some native bee species are specialized pollinators, meaning they exclusively forage pollen from specific plants. And, in Colorado, 70% of our native bees are ground nesters. We can spend thousands of dollars landscaping with traditional lawns without supporting native pollinators because we haven’t created habitats for nester bees. In addition to diverse gardens, healthy soil plays a critical role in supporting pollinator habitat.
What is the difference between generalist bees and specialist bees?
According to Cornell Botanic Gardens, generalist bees collect nectar and pollen from a variety of plant species. Specialist bees collect from a small group of host-plant species, genus, or plant family. In other words, specialist bees have an inherent preference for one kind of host-plant pollen. “They have anatomical and morphological features that are highly adapted to harvesting, manipulating, and transporting the pollen of their preferred host-plant.”
“Numerous studies have documented that these host-plant specialist bees are more likely to be impacted by anthropogenic changes to the landscape - such as fragmentation and habitat loss - than generalist bees.”
How do we build biodiverse landscapes for bees?
1) Start with beauty and enticement. Native pollinating plants are structural, visual, and chemical advertisements to bees. Creating a diverse and vibrant garden ecosystem is crucial for attracting and supporting various bee species.
Native pollinator garden installation designed by Honeywood.
Follow Penn State’s “How to Use a Beescape” to assess the quality of your landscape for supporting bees and other pollinators.
Incorporate a rich diversity of native plants. A variety of flowering plants and grasses provides bees with the essential resources they need for sustenance and reproduction.
Plant height and bloom time are also important to bees and other pollinators. Some pollinators visit and pollinate at different times of the day. For instance, sphinx moths mostly pollinate at dawn or dusk.
Create dense mass plantings and strong seasonal themes focusing on vertical layers and plant sociability.
Bee hotel
2) Build a diverse pollinator habitat.
Use a high coverage of flowering plants - woodies, forbs, grasses.
Use a majority of locally native species. Nativeness is not only about place but also about co-evolved relationships.
Create high family, genus, and species of plant diversity. A rich diversity of food sources creates more resilience.
Sustain pollinator relevant habitat composition by using a regenerative approach to habitat creation and management.
Focus on a combination of native plant communities such as Agastache spp., Echinacea spp., Nepeta spp., Rudbeckia spp., and S. nemarosa to stabilize and attract different pollinator species.
Cornell Botanic Garden notes that specialist bees have a narrow period of adult activity during pollen collection. It’s critical for them to have access to host-plants during this short window of time. “To support the full diversity of solitary, host-plant specialist bees, one needs to remember that each bee species has its preferred host-plant(s), which bloom(s), exclusively during a narrow time period.”
Focus on a variety of spring, summer, and fall blooming native host-plants such as Penstemons, Asteraceae, and Solidago.
Fill numerous spatial and temporal niches with layered plant communities infused with life-supporting elements.
Cornell Botanic Gardens’ Plant for Pollinators recommends creating spaces for native ground nesting bees by leaving areas of bare ground close to host-plants. “Bees construct their nests close to their preferred floral resources, and usually don’t fly more than 500 meters from their nests (this is called their “foraging range”).”
Add other habitat supporting elements - bird baths, bee hotels, log piles.
Never use pesticides or herbicides in or near your garden.
Native bee habitat garden created by Honeywood.
What more can you do?
Discover - Make the world of pollinators and birds more visible to your neighbors and communities by starting in your own yard.
Educate - Teach friends and neighbors about pollinator and bird needs and why they are important to urban centers.
Change - Help create a better landscape culture.
Additional Resources:
The Lives of Bees by Harland Patch, Ph.D.
Native Pollinating Insects Health Study, Colorado Department of Natural Resources
Creating Pollinator Habitat, Colorado State University
Plant for Pollinators, Cornell Botanic Gardens
Specialist Bees, Wild Pollinator Partners
Pollen Specialist Bees of the Western United States by Jarrod Fowler
Pollinator-Friendly Plant Lists, Xerces Society
Honeywood Garden Design helps you create and build regenerative landscapes.
