Roadside Revegetation

PLANNING PHASE ONE: ORIENT
Disturbed reference sites are the best models to demonstrate what is
possible on the site in terms of vegetation, what trajectories succession might
take (with or possibly without human intervention), and ways to effectively
intervene in order to facilitate desired outcomes. Disturbed reference sites
are invaluable in developing realistic DFCs. Ideally, the type of disturbance
on a disturbed site should match the type of road construction disturbance
that will occur on the revegetation unit. For example, if the road cut after
construction will be denuded of topsoil, then a disturbed reference site
should be found that lacks topsoil.
The stage of recovery is also important. It is ideal to find several disturbed
reference sites that represent different successional stages of site recovery
(Figure 4-10). For instance, a revegetation unit would ideally be represented
by a recently disturbed site (several years after disturbance), a recently
recovered site (5 to 25 years after disturbance), and a fully recovered site
(over 25 years since disturbance).
While there is no such thing as a “pristine” plant community, an “undisturbed”
reference site is an area that has not been heavily affected by ground-disturbing
activities. Undisturbed reference sites indicate the highest potential
of a revegetation unit and are most often used as models when the goal is
ecological restoration (re-creation of a plant community identical to that
which existed before disturbance). The description of soil, climate, and
vegetation in an undisturbed reference area often become the framework
for the DFC. It provides the designer with an understanding of those site
characteristics or components necessary for healthy ecological functioning.
The process of selecting and describing reference sites is best accomplished
in an interdisciplinary manner. The discussions that are generated
between soils and vegetation specialists are generally far more thorough in
knowledge and understanding of recovery processes than if surveys were
conducted separately. Disturbed reference sites can be located by driving
the roads in and around the project area and finding areas that appear
similar to the type of road construction being planned for a revegetation
unit. Revegetated road cuts of various ages are good reference sites for
cut slope revegetation units.
4.6 GATHER FIELD INFORMATION
Surveying reference sites, as well as the project area in general, for soils, climate, and vegetation
will provide baseline ecological data for developing the revegetation plan. If creating pollinator
habitat is a revegetation objective, then reference sites and the project area are also surveyed
to assess pollinator habitat quality and pollinator populations. This survey will provide insight
into which pollinator species might be supported or enhanced by the revegetation project. The
goal of the field survey is to obtain sufficient information from reference sites to realistically
define DFCs. During an initial survey, the appropriate survey intensity can be determined
based on information needs and knowledge gaps. For example, if one of the revegetation
objectives is to restore an abandoned road to a DFC similar to a neighboring forest, then a
survey of vegetation and soils of an undisturbed and disturbed neighboring forest would be
conducted to describe the site characteristics and species composition.
The data used to define revegetation units (see Section 4.3 Gather Pre-field Information)
should be reviewed prior to the field surveying of reference sites. Information regarding land
ownership, site history, resources, and past and current management is also valuable. Specialists
who might have knowledge of the soils, vegetation, climate, and hydrology, as well as locals
who can provide information on the site’s history, should be contacted.
Figure 4-10 | Succesional
processes vary by microsite
Successional processes and plant communities
vary considerably based on microsite
conditions. In this example, plant
communities developed differently on
north-facing and south-facing slopes.
Roadside Revegetation: An Integrated Approach to Establishing Native Plants and Pollinator Habitat
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