Skip to main content Accessibility help

Restoring Species Richness and Diversity in a Russian Knapweed (Acroptilon repens)–infested Riparian Plant Community Using Herbicides

  • Roger L. Sheley (a1), Stephen M. Laufenberg (a2), James S. Jacobs (a2) and John Borkowski (a3)


Species richness and diversity are important indicators of ecosystem function and may be related to plant community resistance to invasion by nonindigenous species. Our specific objective was to determine the influence of clopyralid plus 2,4-D, glyphosate, and fosamine, at different application rates and timings, on richness and diversity of total species, total native species, and total nonnative species within a Russian knapweed–infested plant community. Twenty-eight treatments (3 herbicides by 3 rates by 3 application timings, and an untreated control) were applied to two sites located along the Missouri River riparian corridor in Montana. Clopyralid plus 2,4-D, glyphosate, and fosamine were applied in June (spring rosette stage of Russian knapweed), July (bud to bloom stage of Russian knapweed), and August (flowering stage of Russian knapweed). Herbicide rates were clopyralid plus 2,4-D at 0.08 (clopyralid) + 0.42 (2,4-D), 0.13 + 0.67, and 0.18 + 0.92 kg ai ha−1; glyphosate at 0.6, 1.2, and 1.8 kg ai ha−1; fosamine at 3.6, 7.2, and 10.8 kg ai ha−1. Density of each species was recorded during June and August of 2001 and 2002. Species richness and Simpson's Reciprocal Index (1/D) were calculated. By August 2002, only the glyphosate treatment (4.6 species m−2) yielded greater total richness over that of the control (3.5 species m−2). At that time, diversity after applying clopyralid plus 2,4-D remained similar to that of the control (1.4), but glyphosate (2.3) and fosamine (2.0) increased total species diversity. Nonnative grasses and forbs accounted for the increases in richness and diversity. Glyphosate may be appropriate for enhancing ecosystem function and possibly niche occupation to preempt reinvasion by Russian knapweed, but restoring native species seems unlikely using any of these herbicides alone.


Corresponding author

Corresponding author's E-mail:


Hide All
Carpinelli, M. F. 2000. Designing weed-resistant plant communities by maximizing niche occupation and resource capture. . Bozeman, MT Montana State University.
Chapin, F. S. I. 1993. Functional role of growth forms in ecosystem and global processes. Pages 287312. in Ehleringer, J.R., Field, C.B. eds. Scaling Physiological Processe:Leaf to Globe. San Diego, CA Academic.
Cronquist, A., Holmgren, A. H., Holmgren, N. H., Reveal, J. L., and Holmgren, P. K. 1977. Intermountain Flora; Vascular Plants of the Intermountain West, U.S.A. New York, NY Columbia University Press.
Denny, M. K. 2003. Maintaining and establishing culturally important plants after landscape scale disturbance. . Bozeman, MT Montana State University.
Dorn, R. D. 1984. Vascular Plants of Montana. Cheyenne, WY Mountain West.
Egler, F. E. 1954. Vegetation science concepts, I: initial floristic composition-a factor in old-field vegetation development. Vegetatio. 4:412417.
Frank, D. A. and McNaughton, S. J. 1991. Stability increases with diversity in plant communities: empirical evidence from the Yellowstone drought. Oikos. 62:360362.
Hanson, H. C. and Whitman, W. C. 1938. Characteristics of major grassland types in western North Dakota. Ecol. Monogr. 8:57114.
Jorgensen, H. E. 1979. Vegetation of the Yellow Water Triangle, Montana. Billings, MT Montana Department of Fish and Game, U.S. Bureau of Land Management Unnumbered Publication. 57.
Laufenberg, S. M., Sheley, R. L., Jacobs, J. S., and Borkowski, J. 2004. Herbicide effects on density and biomass of Russian knapweed (Acroptilon repens) and associated plant species. Weed Technol. 19:6272.
Mackie, R. J. 1970. Range ecology and relations of mule deer, elk, and cattle in the Missouri River Breaks, Montana. Wildlife Monograph 20. Bethesda, MD The Wildlife Society. 79.
Marrs, R. H. 1985. The effects of potential bracken and scrub control herbicides on lowland Calluna and grass heath communities in East Anglia, UK. Biol. Conserv. 32:1332.
Naeem, S., Chapin, F. S. III, and Costanza, R. et al. 1999. Biodiversity and ecosystem functioning: maintaining natural life support processes. Issues in Ecology 4. Washington, DC Ecological Society of America.
Pokorny, M. L., Sheley, R. L., Zabinski, C. A., Engel, R. E., Svejcar, T. J., and Borkowski, J. J. 2005. Plant functional group diversity as a mechanism for invasion resistance. Restor. Ecol. 13:448459.
Rice, P. M., Toney, J. C., Bedunah, D. J., and Carlson, C. E. 1997. Plant community diversity and growth form responses to herbicide applications for control of Centaurea maculosa . J. App. Ecol. 34:13971412.
Sheley, R. L. and Carpinelli, M. F. 2005. Creating weed-resistant plant communities using niche-differentiated nonnative species. Range. Ecol. Manag. 58:480488.
Spehn, E., Joshi, J., Schmid, B., Diemer, M., and Korner, C. 2000. Aboveground resource use increases with plant species richness in experimental grassland ecosystems. Funct. Ecol. 14:326337.
Symstad, A. J. 2000. A test of the effects of functional group richness and composition on grassland invasibility. Ecology. 81:99109.
Tilman, D. 1997. Community invasibility, recruitment limitation, and grassland biodiversity. Ecology. 87:8192.
Tilman, D., Knops, J., Wedin, D., Reich, P., Ritchie, M., and Siemann, E. 1997. The influence of functional diversity and composition on ecosystem processes. Science. 277:13001305.
Whitson, T. D. 1999. Russian knapweed. in Sheley, R., Petroff, J., eds. Biology and Management of Noxious Rangeland Weeds. 1999. Corvallis, OR Oregon State University Press. 438.


Restoring Species Richness and Diversity in a Russian Knapweed (Acroptilon repens)–infested Riparian Plant Community Using Herbicides

  • Roger L. Sheley (a1), Stephen M. Laufenberg (a2), James S. Jacobs (a2) and John Borkowski (a3)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed