The UF/IFAS Assessment for Invasive Species


Invasive plants significantly impact Florida’s natural environment and are expensive to manage. The University of Florida IFAS Assessment is composed of three tools to assess the status of species currently present in the state and predict the potential invasiveness of species to prevent future invasions. UF/IFAS Assessment evaluations have been used to track the status of nonnatives in Florida, prevent the release of potentially invasive species, and approve new plant varieties as safe alternatives to invasive nonnative landscaping plants.


The Status Assessment

The first tool, the Status Assessment, evaluates the invasiveness of nonnative species that currently occur in Florida’s natural areas. It provides a well-defined system to determine if a nonnative plant species is (or is at risk to be) invasive in Florida’s natural areas.

The Status Assessment consists of questions about ecological, management, and economic aspects of the species and also the species’ potential to expand into non-invaded zones. At least three experts (land managers or scientists) complete questionnaires for the status assessment. Their responses are incorporated with information gathered from an extensive literature search to reach UF/IFAS Assessment final recommendations. The conclusions include plans for regular reassessment.

There are four possible results of the Status Assessment:

  1. Not considered a problem species at this time, may be recommended
  2. Caution, may be recommended but manage to prevent escape
  3. Invasive and not recommended except for “specified and limited” use approved by the UF/IFAS Invasive Plant Working Group
  4. Invasive and not recommended
Predictive Tool

The Predictive Tool determines the invasion risk of species that are not currently found in Florida’s natural areas but are invasive in other places with similar climate and growing conditions. The Predictive Tool is a weed risk assessment (WRA) protocol consisting of 49 questions used to evaluate species either new to the state or proposed for a new use. Each question receives a numerical score between -3 and 5 points (most -1, 0, or 1), and conclusions are made based on the cumulative score. There are three potential outcomes of the Predictive Tool:

  1. Low risk of invasion (<1 point)
  2. High risk of invasion (>6 points)
  3. Evaluate further (between 1 and 6 points)


The Infraspecific Taxon Protocol

The third and final tool, the Infraspecific Taxon Protocol (ITP), evaluates the invasive potential of horticultural and agricultural selections, hybrids, and cultivars of resident invasive species to determine if all taxa associated with particular species should receive the same recommendations.

The ITP consists of 12 questions to determine the following information:

  • If botanists/field personnel will be able to distinguish the taxon from the resident species (or other infraspecific taxa) in the field
  • If the taxon can regress (or hybridize) to characteristics of the resident species
  • The fecundity of the taxon
  • If the taxon displays invasive traits that cause greater ecological impacts than the resident species


The ongoing endeavors of the UF/IFAS Assessment will continue to provide recommendations for nonnative plants to help protect Florida’s natural areas. Visit the UF/IFAS Assessment website at to find the tools and information gathered by the UF/IFAS Assessment team.


Posted: August 1, 2020

Category: Invasive Species
Tags: Assessment, Invasive, Nonnative, Plants, Weed

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