Design - Project Planning and Management for Ecological Restoration - page 86

created, the interpretation of the conditions and the selection of the appropriate technique are not
standardized to the point where individuals not properly trained should be cautioned about the
potential of not meeting expectations.
Vegetation Community
Projects that involve the removal or creation of land formations with different aspects and slopes
affect the vegetation communities that will be restored. Commonly, over the entire range of the
vegetation community there will be different species assemblages. These assemblages may be the
result of the combined influences of topography, altitude, moisture availability, and soil types.
These differences need to be considered and evaluated against the new landform being created
or restored. As discussed earlier, most common modifications are concerned with various types of
waterways and drainages. Such changes will permit the return of a vegetation community that can
persist where one was not possible previously.
Species Palette
Just how many species need to be introduced to a new restoration site? Understanding the species
composition of the vegetation community is an important first step in responding to this challeng-
ing issue. Next is establishing whether there is a need for specific species to serve an identified
function or objective. Some species are consistently found with other species. This can be an
important aspect in the overall performance of a site. Are there any sensitive, threatened, or rare
species for which you will need to provide habitat or forage or which you will need to introduce
directly?
The exact number of species is arguable for any site. In many cases, a species list with percent-
age composition will permit you to make an informed decision. Typically, about 20 percent of the
species will comprise about 80 percent of the vegetation. This is not to diminish the importance
of the remaining species, because restoring biodiversity should be a fundamental objective of all
restoration projects. It is often in the “20 percent” that species of special concern can be found.
Some of these species may serve as a food source or an egg-laying habitat for significant pollinators.
Every effort to accommodate these species should be made.
Typically, the collection of topsoil with the seed bank can be introduced. The goal is to provide
the presence of as many species as possible on the site. The difficult decision is how many more
species need to be introduced on the site. Cost, time, and availability are major factors that will
influence your ultimate decision. Prior to this, however, you should be aware of the species that
are immediately adjacent to your site and the probability of those species naturally invading and
becoming established on your site. Not all species can be easily propagated, nor are they available
at native plant nurseries. Do you have the time to wait for seeds and to propagate them? Do you
have the resources to tend to plant containers and maintain them until planting on-site? Have you
planned sufficiently ahead of time to allow for a nursery to do this work for you? Can the species
be added later and not delay the initiation of the project?