Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Invasion through Quantitative Effects: Intense Shade Drives Native Decline and Invasive Success

Kurt O. Reinhart, Julie Gurnee, Reyes Tirado and Ragan M. Callaway
Ecological Applications
Vol. 16, No. 5 (Oct., 2006), pp. 1821-1831
Published by: Wiley
Stable URL: http://www.jstor.org/stable/40061753
Page Count: 11
  • Download ($42.00)
  • Subscribe ($19.50)
  • Cite this Item
Invasion through Quantitative Effects: Intense Shade Drives Native Decline and Invasive Success
Preview not available

Abstract

The effects of invasive nonnative species on community composition are well documented. However, few studies have determined the mechanisms by which invaders drive these changes. The literature indicates that many nonnative plant species alter light availability differently than natives in a given community, suggesting that shading may be such a mechanism. We compared light quantity (photosynthetically active radiation, PAR) and quality (red : far-red ratio, R:Fr) in riparian reaches heavily invaded by a nonnative tree (Acer platanoides) to that in an uninvaded forest and experimentally tested the effects of our measured differences in PAR and R:Fr on the survival, growth, and biomass allocation of seedlings of the dominant native species and Acer platanoides. Light conditions representative of the understory of Acer platanoides-invaded forest decreased survival of the native maple Acer glabrum by 28%; Amelanchier alnifolia by 32%; Betula occidentalis by 55%; Elymus glaucus by 46%; and Sorbus aucuparia by 52%, relative to seedlings growing in PAR similar to that of native understories. In contrast, Acer platanoides and the native shrub Symphoricarpos albus were not affected by reductions in PAR. Acer platanoides seedlings and saplings are uniquely adapted to shade relative to native species. Acer platanoides was the only species tested that decreased allocation to roots relative to shoots in the invaded forest vs. the native forest light conditions. Therefore it was the only species to demonstrate an adaptive response to the particular light environment associated with Acer platanoides invasion as predicted by optimal partitioning theory. The profound change in light quantity associated with Acer platanoides canopies appears to act as an important driver of native suppression and conspecific success in invaded riparian communities. Further research is necessary to determine whether the effect of nonnative plant-driven changes on light quantity and quality is a widespread mechanism negatively affecting resident species and facilitating invasion by nonnatives.

Page Thumbnails

  • Thumbnail: Page 
1821
    1821
  • Thumbnail: Page 
1822
    1822
  • Thumbnail: Page 
1823
    1823
  • Thumbnail: Page 
1824
    1824
  • Thumbnail: Page 
1825
    1825
  • Thumbnail: Page 
1826
    1826
  • Thumbnail: Page 
1827
    1827
  • Thumbnail: Page 
1828
    1828
  • Thumbnail: Page 
1829
    1829
  • Thumbnail: Page 
1830
    1830
  • Thumbnail: Page 
1831
    1831