Invasive plant species by growth form in northern U.S. forests

Abstract

Invasive plant species (IPS)¹ have been monitored on select Phase 2 (P2) FIA plots since 2005 in the Midwest and since 2007 in the northeastern part of the NRS. In 2005 and 2006, IPS data were collected year-round on 100 percent of the plots. Starting in 2007, the sampling changed to collecting IPS data on 20 percent of plots with the monitoring window running from May through September. Since 2012, IPS data are collected on the Phase 2 Plus (P2+) sample. These plots are a 12.5 percent subsample of the Phase 2 plots, measured from May through September. These plots only occur on forest land.² In this report, the inventory data are presented to examine IPS by growth form: shrub, tree, herbaceous, and graminoid. (Graminoids are grass-like plants.) NRS FIA crews monitored 4,244 plots for invasive plant species in the 2019 inventory. Along with standard forest variables collected during the P2 measurement (e.g., tree diameter, height) these plots have various other attributes collected, including the occurrence and coverage of IPS, vegetation structure, and down woody debris.

Citation

Kurtz, Cassandra M. 2023. Invasive plant species by growth form in northern U.S. forests. Res. Note NRS-312. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station. 6 p. https://doi.org/10.2737/NRS-RN-312.