Invasive species can cause a variety of undesirable changes in forest health simply by altering forest species composition (Fei and others 2014, Kettenring and Adams 2011, Mack and others 2000). In the Eastern United States, forest inventory data suggest that a large proportion of the rural forest area already contains harmful invasive species (Oswalt and Oswalt 2015, Oswalt and others 2015). To further inform forest managers about the relative risks of adverse impacts in different situations, the objectives of this study were (1) to compare forest types in the Eastern United States with respect to the likelihood that they contain invasive forest plants, and (2) to evaluate the relative roles of public versus private forest ownership for conserving the uninvaded forest area. Our goal was to identify forest types with relatively high or low probabilities of current invasion, and to highlight the forest types for which either public or private forest management could be focused on the conservation of the uninvaded area. The study area (fg. 6.1) included the 13 ecological provinces (Bailey 1995, Cleland and others 2007) that contain most of the temperate and boreal forest in the Eastern United States. Almost all of the forest in the region has been modifed by humans, and approximately 40 percent of the original forest area has been converted to other land uses (Smith and others 2009). Approximately three-fourths of the forest area is privately owned (Oswalt and others 2014). Observations made on Forest Inventory and Analysis (FIA) plots have found 71 harmful invasive plant species (as defned by Ries and others 2004) (Iannone 20181) on approximately one-half of the plots surveyed in the study area (Oswalt and Oswalt 2015, Oswalt and others 2015).
Riitters Kurt H.; Potter Kevin M. 2019. Chapter 6 - The invasibility and invadedness of Eastern U.S. forest types. In: Potter, Kevin M.; Conkling, Barbara L., eds. Forest health monitoring: national status, trends, and analysis 2018. Gen. Tech. Rep. SRS-239. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station: 115-124.