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Alien Plants Ranking System

Version 5.1

A cooperative effort of the National Park Service,
Ripon College, University of Minnesota,
and the U.S. Geological Survey

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The Alien Plants Ranking System (APRS) is a computer-implemented system to help land managers make difficult decisions concerning invasive nonnative plants. The management of invasive plants is difficult, expensive, and requires a long-term commitment. Therefore, land managers must focus their limited resources, targeting the species that cause major impacts or threats to resources within their management, or the species that impede attainment of management goals. APRS provides an analytical tool to separate the innocuous species from the invasive ones (typically around 10% of the nonnative species). APRS not only helps identify those species that currently impact a site, but also those that have a high potential do so in the future. Finally, the system addresses the feasibility of control of each species, enabling the manager to weigh the costs of control against the level of impact.

This system has been developed and tested primarily in grassland and prairie parks in the central United States. Using the system in other ecoregions may require modification. If you have comments or suggestions regarding any aspect of this ranking system, please direct them to Dr. Ron Hiebert (

More Information

Enter Enter Bibliography for Alien Plant Ranking System Search

Search Instructions -- Instructions on using the search capabilities at this site.
Sample Entry -- View a sample entry of this resource.
View All Entries -- A PDF file containing all the database entries.  ([an error occurred while processing this directive]) requires a PDF Reader, download free reader

Downloading Instructions -- Instructions on downloading and extracting files from this site
(Download) (3.2M) Alien Plants Ranking System Version 5.1
(Download) (5.2K) Data files for Theodore Roosevelt National Park--South Unit, North Dakota
(Download) (5.4K) Data files for Theodore Roosevelt National Park--North Unit, North Dakota
(Download) (7.0K) Data files for Wind Cave National Park, South Dakota
(Download) (2.4K) Data file of biotic characteristics for all North Dakota and South Dakota exotic plants
(Download) ( 18K) Invasive plants bibliography (Word for Windows)
(Download) (666K) Literature synopses of about 80 species of invasive plants (Word for Windows)
APRS Software: See Instructions
APRS Data Files: Extract the files and copy them to the directory in which APRS software is installed
Invasive Plants Bibliography: Extract the file and open it in Word for Windows
Invasive Plants Literature Synopses: Extract the files and open them in Word for Windows

The ranking system is based on:

Hiebert, R. D., and J. Stubbendieck.  1993.  Handbook for ranking exotic plants for management and control.  U.S. National Park Service Natural Resources Report NPS/NRMWRO/NRR-93/08.

For more information, see:

Hiebert, R. D.  1997.  Prioritizing invasive plants and planning for management.  pp. 195-212 in J. O. Luken and J. W. Thieret, Eds.  Assessment and Management of Plant Invasions.  Springer, New York.

This resource should be cited as:

APRS Implementation Team.  2000.  Alien plants ranking system version 5.1.  Jamestown, ND: Northern Prairie Wildlife Research Center Online. (Version 30SEP2002).

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