Biological Invasions

, Volume 1, Issue 2–3, pp 159–167 | Cite as

Experimental Extinction of Garlic Mustard (Alliaria petiolata) Populations: Implications for Weed Science and Conservation Biology

  • Brian Drayton
  • Richard B. Primack


An assumption of weed science and conservation biology is that small populations are more vulnerable to elimination and extinction than large populations. We tested this with the invasive biennial garlic mustard (Alliaria petiolata). We compared 61 experimental populations from which every flowering plant was removed for 4 years, with 56 control populations. Whereas the majority of the control populations continued to expand in size over the 4 years, experimental populations showed a strong experimental effect, remaining stable in size, declining in size, or going extinct. Small populations were far more vulnerable to extinction than large populations: 43% of small experimental populations (initially fewer than 10 individuals) went extinct, but only 7% of large populations (initially more than 50 individuals). However, some small experimental populations persisted, and in a few cases, larger experimental populations continued to expand even though every flowering individual had been removed. These results and a simple population model suggest the importance of buried seeds in allowing this species to persist despite attempts to eradicate it.

Alliaria extinction weed management conservation biology population size 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anderson RC, Dhillion SS and Kelley TM (1996) Aspects of the ecology of an invasive plant, garlic mustard (Alliaria petiolata), in Central Illinois. Restoration Ecology 4: 181–191Google Scholar
  2. Baskin JM and Baskin CC (1992) Seed germination biology of the weedy biennial Alliaria petiolata. Natural Areas Journal 12: 191–197Google Scholar
  3. Baskin CC and JM Baskin (1998) Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination. Academic Press, Boston, MassachusettsGoogle Scholar
  4. Berger J (1990) Persistence of different-sized populations: an empirical assessment of rapid extinctions in big-horn sheep. Conservation Biology 4: 91–98Google Scholar
  5. Caswell H (1989) Matrix Population Models. Sinauer Association, Sunderland, MassachusettsGoogle Scholar
  6. Cavers PB, Heagy MI and Kokron RF (1979) The biology of Canadian weeds.35. Alliaria petiolata (M. Bieb.) Cavara and Grande. Canadian Journal of Plant Science 59: 217–229Google Scholar
  7. Cousens R and Mortimer M (1995) Dynamics of Weed Populations, Cambridge University Press, Cambridge, MassachusettsGoogle Scholar
  8. Cruden RW, McClain AM and Shrivastava GP (1996) Pollination biology and breeding system of Alliaria petiolata (Brassicaceae). Bulletin of the Torrey Botanical Club 123(4): 273–280Google Scholar
  9. Drayton B (1999) Experimental ecology of plant reintroductions. PhD dissertation. Boston University, Boston, MassachusettsGoogle Scholar
  10. Drayton B and Primack RB (1996) Plant species lost in an isolated conservation area in metropolitan Boston from 1894 to 1993. Conservation Biology 10: 30–39Google Scholar
  11. Hanski IA (1991) Single-species metapopulation dynamics: concepts, models, and observations. In: Gilpin M and Hanski I (eds) Metapopulation Dynamics: Empirical and Theoretical Investigations, pp 17–38. Academic Press, San Diego, CaliforniaGoogle Scholar
  12. Hanski IA and Gilpin ME (1997) Metapopulation Biology: Ecology, Genetics, and Evolution. Academic Press, New YorkGoogle Scholar
  13. Harper JL (1977) Population Biology of Plants. Academic Press, Boston, MassachusettsGoogle Scholar
  14. Husband BC and Barrett SCH (1996) A metapopulation perspective in plant population biology. Journal of Ecology 84(3): 461–470Google Scholar
  15. Jones HL and Diamond JM (1976) Short-time-base studies of turnover in breeding birds of the California Channel Islands. Condor 76: 526–549Google Scholar
  16. Kelly D (1985) On strict and facultative biennials. Oecologia 67: 292–294Google Scholar
  17. Moody ME and Mack RN (1988) Controlling the spread of plant invasions: the importance of nascent foci. Journal of Applied Ecology 25: 1009–1021Google Scholar
  18. Nuzzo VA (1991) Experimental control of garlic mustard (Alliaria petiolata [M. Bieb.] Cavara and Grande) in northern Illinois using fire, herbicide, and cutting. Natural Areas Journal 11: 158–167Google Scholar
  19. Nuzzo, VA (1993a) Current and historic distribution of garlic mustard (Alliaria petiolata) in Illinois. Michigan Botanist: 23–33Google Scholar
  20. Nuzzo VA (1993b) Distribution and spread of the invasive biennial Alliaria petiolata (garlic mustard) in North America. In: McKnight B (ed) Biological Pollution: The Control and Impact of Invasive Exotic Species, pp 137–146. Indiana Academy of Science, Indianapolis, IndianaGoogle Scholar
  21. Nuzzo VA (1996) Fire impact on groundlayer flora in a sand forest 1990–1994. American Midland Naturalist 136(2): 207–221Google Scholar
  22. Primack RB (1996) Lessons from ecological theory: dispersal, establishment, and population structure. In: Falk DA, Millar CI, and Olwell M (eds) Restoring Diversity: Strategies for Reintroduction of Endangered Plants, pp 209–234. Island Press, Washington, DCGoogle Scholar
  23. Thompson K and Grime JP (1979) Seasonal variation in the seed banks of herbaceous species in ten contrasting habitats. Journal of Ecology 67: 893–921Google Scholar

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Brian Drayton
    • 1
  • Richard B. Primack
    • 2
  1. 1.TERC, IncCambridgeUSA
  2. 2.Biology DepartmentBoston UniversityBostonUSA

Personalised recommendations