Invasive forbs differ functionally from native graminoids, but are similar to native forbs

Authors

  • Deborah Scharfy,

    1. Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, CH–8092 Zürich, Switzerland
    2. Present address: Agroscope Reckenholz-Taenikon Research Station, Reckenholzstrasse 191, CH–8046 Zürich, Switzerland
    Search for more papers by this author
  • Andrea Funk,

    1. Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, CH–8092 Zürich, Switzerland
    Search for more papers by this author
  • Harry Olde Venterink,

    1. Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, CH–8092 Zürich, Switzerland
    Search for more papers by this author
  • Sabine Güsewell

    1. Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, CH–8092 Zürich, Switzerland
    Search for more papers by this author

Author for correspondence:
Deborah Scharfy
Tel: +41 44 377 75 73
Email: deborah.scharfy@env.ethz.ch

Summary

  • Exotic plant invasions can alter ecosystem processes, particularly if the invasive species are functionally different from native species. We investigated whether such alterations can be explained by differences in functional traits between native and invasive plants of the same functional group or by differences in functional group affiliation.
  • We compared six invasive forbs in Europe with six native forbs and six native graminoids in leaf and whole-plant traits, plasticity in response to nutrient supply and interspecific competition, litter decomposition rate, effects on soil nutrient availability, and allelopathy. All traits were measured in a series of pot experiments, and leaf traits additionally in the field.
  • Invasive forbs differed from native forbs for only a few traits; they had less leaf chlorophyll and lower phosphorus (P) uptake from soil, but they tended to have a stronger allelopathic effect. The invasive forbs differed in many traits from the native graminoids, their leaves had lower tissue densities and a shorter life span, their litter decomposed faster and they had a lower nitrogen-use efficiency.
  • Our results suggest that invasive forbs have the potential to alter ecosystem properties when invading graminoid-dominated and displacing native graminoids but not when displacing native forbs.

Ancillary