Why are plants being screened using a weed risk assessment?
The purpose of the weed risk assessment is to identify high-risk species (likely invasive pests plants), allowing us to make informed decisions that will reduce the economic and ecological harm caused by invasive plants in Hawaii and on other Pacific Islands. Of course, many introduced plants provide significant benefits to humans, and such benefits also need to be considered when making planting or importation decisions.
If
you are unfamiliar with invasive pest problems in Hawaii, you may wish to see
the overview: The silent invasion
Are the weed risk assessments legally binding?
No. The assessments allow you to make informed decisions.
How are weed risk assessments done?
The weed risk assessment (WRA) uses 49 questions to obtain a score for each
species. A high scoring plant poses a high risk of becoming an invasive pest in
Hawaii and other Pacific Islands. The weed risk assessment is a pro-active
tool to identify plants that pose the highest risk of causing ecological or
economic harm. It is based on the species' biology, geographic
origin, and pest status elsewhere as well as published information on the
species' behavior in Hawaii. It does not make use of unpublished observations on
the species' behavior in Hawaii.
Blank
assessment sheet
How
well does the assessment system work?
Based on test runs with nearly 200 plant species, the weed risk assessment
system correctly identifies approximately 95% of serious pest plants in Hawaii
and other Pacific Islands. The system correctly classifies 80-85% of non-pest
plants.
More details on
scientific findings
Can
WRA ratings change?
The
goal of the assessment process is to provide the best available information
about the behavior of introduced plants in Hawaii and on other Pacific Islands. Currently, there are two
processes by which the WRA rating for a species may change: 1)New or overlooked
published information could change the answers to one or more of the 49 risk
assessment questions, thereby changing the WRA score and rating, or
2)Unpublished information reported to and reviewed by a committee of plant
experts (HEPEP)
indicates that an "ok" rated species currently causes significant harm
in native or managed ecosystems of Hawaii. This second process is evolving.
Nevertheless, in the interest of providing the most accurate assessments
possible, we invite you to submit information:
Report
new or missing information
Why can't I find an assessment for my favorite species?
Please use our search interface to be certain that
your species is not listed under a synonym. We are working to complete
additional assessments. If you would like to recommend a species for assessment,
please contact Teresa Trueman-Madriaga (Kaulunani Urban Forestry
Program, ttm@hawaii.rr.com)