What is the Invasive species Tier list?
We maintain a categorized list of invasive species across the LIISMA region to help inform management in accordance with regional priorities. The tier list puts species in categories based on impact, location, abundance, distribution and feasibility of response. LIISMA’s Tier Ranking List relies heavily on New York State Invasiveness Ranking Assessments conducted by the NYSDEC.
Learn more about how the tier list was generated in this ArcGIS StoryMaps!
Tier descriptions
0: Nonnative, Naturalized Species- Species with insignificant impact, or potentially so, that are present in LIISMA. Management is unnecessary unless it is intended to protect regional conservation targets and to meet conservation management goals.
1: Prevention/EDRR (Early Detection, Rapid Response)- High and very high impact species not yet in LIISMA, or their location is not understood. Highest level of invasive species management. Conduct delineation surveys, engage citizen scientists to detect and report, and assign to appropriate tier if detected. Manage high priority areas and pathways to resist and
prevent invasion.
- 1a: Prevention/EDRR- High and very high impact species, or potentially so, within a 100-mile buffer, with potential for establishment.
- 1b: Prevention/EDRR – High and very high impact species, or potentially so, in Eastern North America, with potential for establishment.
- 1c: Prevention/EDRR – High and very high impact species, or potentially so, far outside the buffer and not in Eastern North America, but an introduction pathway exists.
2: Eradication- High and very high impact species, or potentially so, with low enough abundance to make eradication feasible within LIISMA. Highest level of rapid response efforts. Need delineation surveys and citizen science to determine the full extent.
3: Containment- High and very high impact species, or potentially so, that are too widespread in LIISMA for eradication, but low enough in abundance to consider local or regional containment. Target strategic management to slow the spread, since surrounding sites and regions could be at risk if left unattended.
4: Local control- High and very high impact species, or potentially so, that are well-established. Eradication at the regional level is not feasible. Consider localized management to contain, exclude, or suppress, only if justified and feasible to protect regional conservation targets and to meet conservation management goals.
Species that need more research, mapping, and monitoring to understand their invasiveness. This includes naturalized species and
cultivated-only species that are known to be invasive in other regions but are not yet invasive here. Invasiveness may change with
environmental or genetic changes. Should monitor populations on a regular basis to see if they are starting to become invasive and assign
to appropriate Tier if invasive infestations detected.
Resources
What it means for you
- Do not plant tier listed species, or any species on the state regulated list
- During vegetation management, look for emerging invasive species (Tier 2)
- Report and control if found.
