Incorporation of Pollinator Plantings to Enhance Ecosystem Functions and Durability of Transportation Right-of-Way Infrastructure

Details

• Creators:
  Brown, Rebecca Nelson ; Lopardo, Sophia
• Corporate Creators:
  University of Rhode Island ; University of Maine. Transportation Infrastructure Durability Center (TIDC)
• Corporate Contributors:
  United States. Department of Transportation. Office of the Assistant Secretary for Research and Technology ; United States. Department of Transportation. University Transportation Centers (UTC) Program
• Subject/TRT Terms:
  Durability Ecosystems Evaluation Habitat Highways Infrastructure Landscape Maintenance Methodology Plants Pollinators Right Of Way (Land) Roadside Soils Vegetation Control

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• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; New England
• Corporate Publisher:
  University of Maine. Transportation Infrastructure Durability Center (TIDC)
• Abstract:
  Monarch butterflies, ground-nesting bees and many other crucial pollinators depend on early succession grassland habitats for survival. In New England these habitats have been disappearing as agricultural lands are developed or allowed to mature into forest. Many of our native pollinator species are threatened or endangered. Highway clear zones and rights-of-way have become a primary source of early succession habitat. The linear nature of highways also facilitates connections and migration of pollinators between other sources of early succession habitat such as pollinator meadows, agricultural lands and natural areas. However, highway rights-of-way have not traditionally been managed as pollinator habitat. Limited access highways in New England and the Northeast were modeled after the parkways of the early 20th century, with their manicured lawns and carefully pruned ornamental plantings. In the intervening years landscape management intensity has decreased but mowed turfgrass remains the default ground cover. Establishment of pollinator plantings poses a challenge for managers of rights-of-way. Departments of transportation and the landscape installation companies they contract with are experienced at establishing cool-season turfgrasses using hydroseeding, and at establishing perennial forbs from container-grown transplants. However, they have little experience establishing native grasses and forbs from seed, and the lengthy pre- and post-seeding maintenance protocols recommended to minimize weed intrusion do not fit with existing project timelines. Selection of plant materials is also an issue as existing recommendations for roadside wildflower plantings come from outside of New England, and contain species or ecotypes that are not native in New England or not well adapted to New England soils and climate. Existing resources on establishment of pollinator plantings in New England are intended for homeowners, farmers or managers of natural areas and assume a very different set of management resources than what is available for highway rights-of-way. Finally, most of the available resources on roadside use of native plants do not include information on the pollinator benefits of the recommended species. This project addressed these knowledge gaps through three inter-connected tasks. A seed mix of regionally native grasses and insect-pollinated forbs was established using five different methods and then monitored for three years to identify effects of establishment method on the species composition of the resulting plant community. Twenty-six insect-pollinated forb species that are native to Rhode Island and have potential for use in roadside pollinator habitat were transplanted into the roadside environment and data were collected over two years on survival and growth. Existing lists of native species, of pollinator species, and of species suitable for the roadside environment were reviewed and combined to identify native woody plants that could be used in landscape plantings in highway rights-of-way to support pollinators during seasons when native forbs are not in flower. The project determined that broadcast seeding into plantable soil was the best method for establishing native forbs on roadsides, identified twelve species that are good candidates for inclusion in pollinator-friendly seed mixes for roadsides in Rhode Island and 14 species that should not be used, and created a guide to pollinator-friendly native woody plants for use by landscape architects in New England.
• Format:
  PDF
• Funding:
  69A3551847101
• Collection(s):
  University Transportation Centers
• Main Document Checksum:
  urn:sha-512:4a9a9dbf65b5df4260b815d25f303e56b9c58cbce74d9eaef8d93a04cdd2ef4d4ffd147cd3813cdebcd8b5a5515b66545d07660b87fbda8337d82e0cf97cfb41
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88799/dot_88799_DS1.pdf
• File Type:
  [PDF - 14.96 MB ]