Roadsides as Habitat for Pollinators: Management to Support Bees and Butterflies

Pollination of flowering plants is an essential ecosystem service. It is estimated that 85% of flowering plants worldwide and 35% of global crop production rely on animals for pollination. Pollinators such as bees, flies, wasps, beetles, moths, and butterflies play multiple roles in food webs in addition to facilitating the reproduction of flowering plants. Fruits and seeds, the product of pollination, are an important part of the diet of many birds and mammals, and pollinators are a direct food source for other wildlife such as songbirds and even grizzly bears as well. However, research indicates that some managed and wild pollinators are in decline. Threats to pollinators affect not only pollinators themselves but also the stability of natural ecosystems and agricultural productivity. Roadsides are known to have value as habitat for plants, as well as birds, small mammals, amphibians, reptiles, ants and beetles. Roadsides can also be a refuge for pollinators, especially in landscapes substantially altered by urbanization or agriculture. Often the only semi-natural areas remaining in heavily altered landscapes, marginal habitats like roadsides can provide pollinators with places to forage for food and to nest. Pollinator habitat must include blooming flowers, which supply pollinators with protein-rich pollen and energy-providing nectar. Pollinators also require a place to nest or to lay their eggs. Butterflies and moths generally lay their eggs on or next to the host plant upon which their vegetation-eating caterpillars will feed. In contrast, bees create nests in which they leave food for their young. Many bee species dig subterranean nests in their preferred soil type, while other species nest above ground in plant stems or cavities in dead wood. Bumble bees nest within insulated cavities, under clumps of grass or in old rodent burrows. Studies demonstrate that roadsides planted with native plants support more butterflies and bees than do roadsides dominated by non-native grasses and flowers. With millions of acres of land in roadsides, managing roadsides with pollinators in mind could have a significant impact on pollinator conservation. New roadside plantings should include a diversity of native wildflowers with overlapping bloom times, to provide for pollinators throughout the growing season, including key host plants for butterflies. For example, monarch butterflies, renowned for their impressive long-distance seasonal migration, rely on milkweed species only as host plants. Monarch populations have been declining over the last fifteen years, and reduced numbers of milkweeds across the butterfly’s breeding range, particularly within agricultural fields, are likely contributing to their decline. Planting milkweeds along roadsides can restore monarch breeding habitat, including along migration routes. Roadsides can be of great benefit to pollinators. Best management practices include consideration of timing and frequency of mowing, spot spraying rather than broadcast use of herbicides, and surveys to identify existing roadside habitat that provides native plant resources for wildlife. Roadside managers can develop a management strategy that addresses safety concerns while also benefiting wildlife such as pollinators.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: Proceedings of the 2013 International Conference on Ecology and Transportation (ICOET 2013)

Subject/Index Terms

Filing Info

  • Accession Number: 01558283
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 28 2015 8:06PM