Across New York State, the Partnerships for Regional Invasive Species Management (PRISM) Network uses a standardized, data-driven Tiered List approach to prioritize invasive species prevention and management. This system, developed by the New York Natural Heritage Program (NYNHP) using data from iMapInvasives, categorizes high-impact invasive species based on their abundance, distribution, and feasibility of management. It provides a unified framework to guide regional decision-making and ensures that management actions align with the invasion curve and available resources.

The Tiered List assigns species to one of several groups. Tier 1 species are high-risk threats not yet present within a region but found nearby, making them prime targets for early detection and prevention. Tier 2 species are present at low abundance, where eradication remains feasible. Tiers 3 and 4 include species with increasing levels of establishment that require strategic suppression or localized control, while Tier M identifies species that warrant additional monitoring or research to better understand their impacts.

Within this statewide structure, SLELO PRISM refines the full list into a more focused, program-specific set of priority species. By distilling hundreds of statewide listings into a manageable subset, SLELO equips partners, land managers, and community members with clearer guidance for detection, reporting, and action. This localized list highlights species that pose the greatest ecological risk to the region and represents those most actionable based on current data and management capacity.

SLELO’s priority species span the full range of tiers from prevention targets such as Hydrilla and Spotted Lanternfly to management-intensive species like knotweeds, Phragmites, and hemlock woolly adelgid. Each listing reflects the best available science, regional mapping data, and expert evaluation, helping ensure that resources are allocated where they will have the greatest ecological return.

To explore SLELO’s regional priority Tier list, statewide tier tables and interactive maps, visit the SLELO PRISM website.