illustration of a green map with red and tan lines and location markers
Source: USDA Forest Service

Invasive Species Maps

The threat of nonnative invasive plants in the nation’s forests is an ever-growing concern. Their aggressive nature allows many of them to out-compete native species, causing ecological and economic harm. The Forest Inventory and Analysis (FIA) program of the USDA Forest Service is taking an active role in the inventory and monitoring of these species in order to provide statistically valid estimates of their distribution and abundance. While a national protocol has been established to describe the process of collecting invasive vascular plant data, each FIA region is responsible for identifying the most important invasive plants to monitor on its forestlands. The list developed by the Northern Research Station currently includes 43 species. Data collection at the Northern Research Station for these 43 species began in 2007 and continues on 5-year cycle.

These maps depict the distribution of these species using the 2007-2009 inventory data. Each layout accessible on this page includes a county choropleth map with colors indicating the percentage of forested field plots on which a particular invasive plant species was found. An inset map depicts approximate locations of field sites. Each map is accompanied by color photos of the plant. Maps are organized into five categories: trees, shrubs, vines, herbs, and grasses. For more detailed information on each plant species refer to the field guide at

Resource Category: Maps, Website / App