Rapid shifts in the chemical composition of aspen forests: An introduced herbivore as an agent of natural selection

Joseph K. Bailey, Jennifer A. Schweitzer, Brian J. Rehill, Duncan J. Irschick, Thomas G. Whitham, Richard L. Lindroth

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


The global ecological impacts of introduced and exotic species can be dramatic, leading to losses in biodiversity and ecosystem "meltdown", however, the evolutionary impacts of introduced species are much less understood. Further, very few studies have examined whether mammalian herbivores can act as agents of natural selection for plant traits. We examined the hypothesis that variation in aspen phytochemistry resulted in selective herbivory by Cervus elaphus (elk), an introduced mammalian herbivore. With the experimental removal of a large elk exclosure, elk selectively eliminated 60% of an aspen population previously protected from herbivory resulting in a dramatic shift in the phytochemical composition of the aspen forest. Selection gradients (β) varied from 0.52 to 0.66, well above average relative to other studies of selection. These results indicate that introduced herbivores can have rapid evolutionary consequences even on long lived native species. Because there are fundamental links between phytochemistry, biodiversity and ecosystem processes, the effects of an introduced herbivore are likely to have cascading impacts on the services ecosystems provide.

Original languageEnglish (US)
Pages (from-to)715-722
Number of pages8
JournalBiological Invasions
Issue number6
StatePublished - Aug 2007


  • Aspen
  • Elk
  • Herbivory
  • Introduced species
  • Natural selection
  • Phytochemistry
  • Plant animal interactions
  • Populus

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology


Dive into the research topics of 'Rapid shifts in the chemical composition of aspen forests: An introduced herbivore as an agent of natural selection'. Together they form a unique fingerprint.

Cite this