Roadside Revegetation

INTRODUCTION
and others 2016, and case studies in this report). Designers have created “pollinator-friendly”
roadside habitat, and agency maintenance departments have altered procedures to better
maintain these habitats with a focus on the needs of pollinators.
While the publications above assess the best available conceptual and theoretical information,
each also recognizes extensive needs for further work, particularly in developing practical
approaches to integrating ecological needs with transportation goals. Central to ecosystem
function is native vegetation (SER 2004). However, much of the pertinent information
related to protecting and establishing native plants on roadsides has been scarce, scattered,
unexamined, or not translated into practice. This report is intended to bridge some of the
informational, technical, and organizational gaps to facilitate successful roadside revegetation
with native plants. An integrated approach is offered to support both designers and field-based
practitioners in successfully revegetating roadsides and obliterated roads with native plant
communities (Figure 1-3).
1.2.5 WHY REVEGETATE ROADSIDES WITH NATIVE PLANTS?
Figure 1-3 | Recently planted
trees on an obliterated section
of highway in Oregon
Most road projects today do not involve
building new roads, but rather modifying
or obliterating existing roads.
Long-term economic and ecological advantages can be gained by establishing desirable native
plant communities on roadsides (Berger 2005). Roadside vegetation can support safety goals by
reducing headlight glare, reinforcing the road alignment, serving as crash barriers, protecting
view planes and visibility, controlling snow drifts, and reducing wind speeds (Forman and
others 2003). Pollinator-friendly plants species (namely showy flowering plants) can improve
the experience of the road user by creating natural beauty via plant form and color diversity
along the roadside, in addition to improving driver performance by reducing monotony
and stress. Importantly, creating pollinator habitat along roadsides can directly support
imperiled pollinators such as the iconic monarch butterfly (Danaus plexippus), economically
important managed species such as the European honey bee (Apis mellifera), as well as a
wide variety of native pollinators including wild bees, butterflies, moths, flies, beetles, and
wasps. A self-sustaining native plant community on a roadside stabilizes slopes, protecting
water and soil quality. In addition, the establishment of healthy native plant communities is
often the best long-term defense against invasive and noxious weeds. Maintenance costs
for managing problematic vegetation are reduced, as is the pollution and controversy that
sometimes results from roadside herbicide use (Berger 2005). Establishing healthy roadside
vegetation can also help sequester carbon dioxide, one of the factors responsible for global
climate change (Palumbo and others 2004, Ament and others 2013).
Using native vegetation supports every aspect of the goals identified as best management
practices by the transportation community for road design. These include goals to:
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Produce a safe, cost effective, environmentally friendly, and practical road design that
is supported by and meets the needs of the users
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Protect water quality and reduce sediment loading into water bodies
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Avoid conflicts with land use
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Protect sensitive areas and reduce ecosystem impacts
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Maintain natural channels, natural stream flow, and passage for aquatic organisms
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Minimize ground and drainage channel disturbance
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Control surface water on the road and stabilize the roadbed driving surface
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Control erosion and protect exposed soil areas
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Implement needed slope stabilization measures and reduce mass wasting
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Avoid problematic areas
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Stormproof and extend the useful life of the road (Keller and Sherar 2003)
Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat 5