The Lower Hudson PRISM's Focal Species Working Group has categorized many of the invasive species found within the PRISM region into 5 Tiers: Tier 1 - threat, Tier 2 - emerging, Tier 3 - established, Tier 4 - widespread, and Tier 5 - watch species. The tier categorization was created as a way to standardize categories throughout New York State. This is a working list and should not be considered a finalized list.
- v2.0 Updated April 8, 2019 - adds forest pests and aquatic invasive species as well as additional terrestrial plants.
- v1.3 Updated Final Draft February 12, 2018 - Working group: Linda Rohleder, Daniel Atha, David Decker, Tait Johansson, Tom Lewis, Chris Mangels, Tim Wenskus, and Michael Young.
- v1.2 Updated Final Draft January 22, 2018 - see above.
- Updated Final Draft May 30, 2017 - Working Group: Linda Rohleder, Daniel Atha, David Decker, Tait Johansson, Tom Lewis, and Chris Mangels. Additional contributors include: John Mickelson, Molly Marquand, Tierney Rosenstock and Tim Wenskus.
- Original Draft March 7, 2016 - Working Group: Daniel Atha, Tom Lewis, Chris Mangels, John Mickelson, Linda Rohleder, Tierny Rosenstock, Tim Wenskus. Also participating Tait Johansson, David Decker. With Contributions from: Samantha Epstein, Chris Doyle, Steve Young, and Mike Van Clef.