Making Space for Pollinators

by Liia Koiv-Haus, ASLA

Black-eyed susans and solar panels
image: OpenEI / Creative Commons Zero

At least one third of the food we eat and 75% of flowering plants depend on pollinators: bees, butterflies, moths, bats, birds, wasps, beetles, and other insects (Natural Resources Conservation Service). Meanwhile, pollinator decline is happening due to loss of habitat, disease, parasites, and changing climate. In 2015-2016, 44% of managed bee colonies in the U.S. were lost (Bee Informed Partnership). Continuous declines in bee populations have caused prices for renting bees to skyrocket to four times the price they were in 2004. Data on wild pollinators is lacking, but overall pollinators are declining in 70% of countries due to changing land use patterns, pesticides, and other factors (Apidologie).

In 2014, the Obama Administration established a Pollinator Health Task Force with representatives from departments, agencies, and offices. This task force developed a National Pollinator Health Strategy with an action plan to conduct research on pollinators and restore habitat, prioritizing high risk areas. The action plan involved data collection, sharing, and modeling; strategies for creating affordable seed mixes, especially on post-fire restoration projects; preventing pollinator exposure to pesticides; producing a public education plan; and developing public-private partnerships. A major goal was to increase sheer land area of pollinator habitat, which has spurred strategic planning efforts.

One example strategy to promote pollinator health has been the “colocation” of solar panels and plants to maximize land use benefits: planting native wildflowers and grasses among rows of solar panels.

Ground-mounted solar is expected to triple by 2030 (Office of Energy Efficiency & Renewable Energy). Growth in solar energy reduces carbon emissions but can also create competition with agricultural land and disturb natural habitats. A cost-benefit analysis of a pollinator planted solar farm in Minnesota showed that private landowners might benefit financially from colocation due to higher energy output, reduced mowing costs, and improved crop yields at neighboring farms (Yale Center for Business and the Environment). This study considered positive externalities resulting from plantings, including carbon sequestration, soil restoration, and groundwater recharge. Colocation is not just for agricultural areas—rooftop pollinator gardens with solar panels can improve energy efficiency of buildings.

Interestingly, urban areas have lost fewer pollinators than agricultural areas. Cities provide more diversity in plants compared to conventional farms (Ecological Entomology). With crop monocultures, a plant species will only bloom during a certain time, but bees need food beyond that period to survive. Planting a diversity of plants that bloom at different times of the year provides food for bees throughout the growing season. It is also important to incentivize plantings outside of areas where pesticides are applied. The EPA discourages homeowners from applying toxic neonicotinoids on yards and discourages use of neonicotinoids on flowering crops to protect pollinators, but they are still permitted on crops (EPA). By incentivizing planting wildflowers and hedgerows near agricultural land, government programs help restore pollinator populations. The USDA’s Pollinator Habitat Initiative and Conservation Reserve Program pay landowners, farmers, and ranchers to maintain pollinator habitat (FSA).

Another federal agency working to promote pollinators is the U.S. Department of Transportation. They have established best management practices for DOTs to improve habitat for pollinators, including protecting existing stands of native vegetation, adjusting mowing practices, reducing herbicide use, and diversifying vegetation through reseeding efforts post-construction. Many state and local transportation agencies designate “zones” along roadways where grass must be mowed for visibility in the “clear zone” for safety reasons but kept tall for pollinators in the “operational zone.” These policies reduce maintenance costs, noise pollution, and air pollution by reducing the need for mowing.

See “Roadside Realm” from the March 2021 issue of Landscape Architecture Magazine for more on roadside vegetation. / image: Flickr

In addition to highway corridors, yards are necessary to create pollinator habitat “bridges” between larger open spaces. Some cities are revising their ordinances to permit “unkempt” front yards to support pollinators. Several communities in Wisconsin suspended enforcement of long-grass ordinances in May 2021 to protect pollinator habitat early in the year, during a vulnerable time for pollinators. Even weeds like dandelions bloom with flowers that are food for pollinators, so mowing your lawn and cutting those flowers starves pollinators. Dead leaves and brush provide habitat for nesting and overwintering insects and return nutrients to the soil, so raking and bagging leaves in the fall sometimes does more harm than good. Leaf litter that enters storm sewers, however, can add nitrogen and phosphorous to neighboring water bodies, so municipalities must strike a balance between limiting excess debris to improve urban water quality and promoting pollinator health.

As cities legalize beekeeping and modify their codes to permit more pollinator habitat, we have seen an increase in urban bees. Beekeeping and gardening grew as hobbies during the pandemic, especially in major cities. This is mostly a good thing, but some scientists are concerned the increase in bees is a threat to native pollinators since they compete for food.

Ultimately, we need more research to back future initiatives, so citizen scientists are working to create a pollinator database. Many grassroots groups are creating change through volunteer planting and seeding and data collection to map pollinator habitat. Major nonprofit players include the Xerces Society for Invertebrate Conservation, Monarch Joint Venture, and the People and Pollinators Action Network (PPAN). The North American Pollinator Protection Campaign is a group of scientists, researchers, conservationists, government agencies, and volunteers with a mission to improve pollinator health and habitat throughout North America. They have released Ecoregional Planting Guides to aid in native plant restoration efforts.

One crucial aspect of restoring pollinator habitats is ensuring that selected plants and seed mixes are native and have evolved with the insects of the region. It is important for pollinator protection efforts to be focused regionally because native plant species vary at the regional level. Most people know that milkweed and monarchs have evolved interdependently, but other species of plants and insects have done the same. For example, mangoes, bananas, and agave depend on bats for pollination. What’s needed most are large-scale regional efforts, with regions working concurrently to rebuild native pollinator habitat and resiliency. We can learn a lot from bees and their emphasis on the collective effort and common good. Only by joining forces at a large scale can we solve the pollinator pandemic.

Liia Koiv-Haus, ASLA, is a Landscape Specialist for the Colorado Department of Transportation. She also serves as an officer for ASLA’s Landscape—Land Use Planning Professional Practice Network (PPN).

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