A review of NPS species, the national database registering plant occurrence in parks, indicated that 465 plant species occurred in Hopewell Culture National Historical Park. Of these, 148 (32%) are non-native, meaning that these plants were recently introduced through human agency. The authors detail the status of invasive plants and the resource management issue(s) for the park.

The authors conducted a second year of invasive plant surveys at Lincoln Boyhood National Memorial. This allowed a comparison of invasive plant species found in 2006 to those found in 2011. their findings are detailed in this publication.

During surveys in 2009, we documented seven invasive exotic plant taxa in the Big Spring Pines Natural Area, Chubb Hollow, Long Bay Field and Long Bay at Ozark National Scenic Riverways. All species were known to occur on the park. The most widespread and abundant of the exotic plant species observed included Johnsongrass, ground ivy and Nepalase browntop. Each of these species covered seven or more acres in the park. In general, several invasive exotic plants are a major problem in the study area at Ozark National Scenic Riverways, but successful control is possible for a large group of...

During surveys in 2006, the authors documented 13 invasive, exotic plant species and the native Eastern red cedar on Pea Ridge National Military Park. The survey focused on the relatively mature forests at the park to the exclusion of old fields and successional forests.

During surveys in 2006, the authors documented 35 invasive, exotic plant species on Wilson's Creek National Battlefield. Their findings are detailed in this report.