Early Detection Surveys
way to stop the damage an invasive species may inflict on an ecosystem is to
control or eliminate the species when its populations are still small. However,
scientists cannot detect every single patch of an invasive species - they simply
don't have the time or resources. Students and other volunteers can help scientists
by conducting early detection surveys.
An early detection survey locates problem species that are
in the process of invading an area. For example, an early detection survey
could be used to determine whether purple loosestrife is present in a wetland.
While it is important to eventually determine the size of invasive species
patches in an ecosystem, early detection surveys are only conducted to determine
if a species is present or absent.
Early Detection Survey Technique
Using the method described below, you will be able to determine
if the invasive species in which you are interested has invaded a specific
- Maps of the area you will survey
- Learn about invasive species of concern in your area,
particularly those that are just beginning to invade. You may find information
on one of the websites listed on our links
page. Another option is to contact an organization concerned about your local
environment and/or invasive species (for example, a land trust, your local town
conservation commission, state parks, university departments, the Nature Conservancy).
These organizations will likely be able to provide you with information about
local invasive species, and may even ask you to conduct a survey on their land.
upon which species you will look for, and which area should be the focus of your
survey (for example, a state park, a nature preserve, or your school's property).
how to identify the species for which you will be searching. The library, local
environmental organization, or websites may have useful identification guides.
Be sure that your species is easily recognized during the time of year in which
you will be searching for it.
- Decide on a survey method. Because invasive
species often first invade travel corridors (for example, roads and hiking trails),
you may want to focus your search along these areas. Consider in what types of
habitats your invasive species grows. Mark the sites to be surveyed on your map.
through your site and record information about your invasive species. For example,
you may want to walk all of the trails in a nature preserve. Record what you noticed,
including information on whether the species was present and if so, in what quantities.
you move to the next site, clean off your shoes and remove any plant parts that
may be attached to your clothes. This will help prevent invasive species from
spreading to new sites.
- Record on your map where the invasive species
was found. If you are working with a local organization, be sure to report your
findings to them.
Based on the data you have recorded on your map and in your
field notebook, is the species you surveyed coming into your study area? What
type of sites is it colonizing? Are its populations large or small? Do your
results agree with your predictions? For example, if you expected to find a
species, was it present?
If you (or your friend or classmate) conducted a similar study
on a different study site, compare your results. Was the same invasive species
present in both sites? Was the species present in similar amounts (size of
patches, density, etc)? Why do you think this is the case?
For more information on how to analyze or report your results,
consult Invasion Ecology.