Iowa’s maintenance practices are setting an example for accommodating dwindling bee and butterfly populations.
Leader in Mowing
Across the country, populations of bees, butterflies and other pollinators are declining rapidly. To better support the restoration of these populations, departments are adjusting their management of roadside grasses. Conservationists are working with transportation officials to increase the amount of vegetation along roadsides, where mowing practices have depleted many habitats for the pollinators.
The Xerces Society, a nonprofit conservation organization, is working with the U.S. Department of Transportation to reform roadside mowing practices nationwide so as to protect landscapes vital to pollinator sustainability. Iowa currently implements sustainable roadside mowing practices that the USDOT may use to model national reforms and best practices. Iowa currently boasts:
- A robust native plant program
- A native seed market
- Limited use of herbicides in roadways
- Restricted mowing rules
Furthermore, Iowa restricts roadside mowing after July 15, within 10 feet of the roadway. Throughout the year, the state limits mowing to just two or three times, while the state regulates herbicides that have been found toxic to bees, The Gazette reported.
Problems with Compliance
While Iowa is clearly ahead of the curve in pollinator conservation, the DOT continues to struggle with regulatory compliance. Many residents may mow along the roads or aesthetic reasons, while restricted herbicides may be used on wildflowers planted for pollinators but mistaken as weeds.
Studies suggest that the prime time for mowing coincides with when plants are flowering. The mowing then disrupts the plants reproductive cycles, directly harming butterfly and bee populations. If the state mows earlier in the season, many birds will be impacted by having their nesting grounds disturbed. On the other hand, if the mowing is postponed until the first frost, there is limited resources available as crews are preparing for fall and winter, The Gazette reported.
Despite having planted more than 100,000 acres of combined native grasses and wildflowers since 1998, Iowa officials still report a steady decline in butterfly and bee populations. The commercial honeybee population has declined 40 percent since 2006, while just 56 million butterflies remain from the 1 billion recorded in the 1990s, The Gazette reported.
Greenpeace International attributes the majority of the population loss to:
- Loss of biodiversity
- Destruction of habitat
At the federal level, the U.S. Fish and Wildlife Service has launched a $20 million national effort to preserve butterfly populations in key regions. The program focuses on planting milkweed and nectar plants to promote habitat growth across the country. To combat a nearly 90 percent decline in butterfly populations, the program will build a network of diverse conservation partners and stakeholders to protect and restore key habitats. The most significant of threats to butterflies include loss of habitat to:
- Agricultural practices
- Land development
- Cropland conversion
From California to the Corn Belt, the Service will also fund numerous conservation projects totaling $2 million this year to restore and enhance more than 200,000 acres of habitat for monarchs while also supporting over 750 schoolyard habitats and pollinator gardens. Many of the projects will focus on the I-35 corridor from Texas to Minnesota, areas that provide important spring and summer breeding habitats in the eastern population’s central flyway.
Protecting the monarch is not just about saving one species. The monarch serves as an indicator of the health of pollinators and the American landscape. Monarch declines are symptomatic of environmental problems that pose risks to our food supply, the spectacular natural places that help define our national identity, and our own health. Conserving and connecting habitat for monarchs will benefit other plants, animals and important insect and avian pollinators