Journal cover Journal topic
Web Ecology An open-access peer-reviewed journal
Journal topic
Volume 8, issue 1
Web Ecol., 8, 142-159, 2008
https://doi.org/10.5194/we-8-142-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.
Web Ecol., 8, 142-159, 2008
https://doi.org/10.5194/we-8-142-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

  17 Dec 2008

17 Dec 2008

Changes in species composition in alpine snowbeds with climate change inferred from small-scale spatial patterns

C. Schöb1, P. M. Kammer2, Z. Kikvidze3, P. Choler4,5, and H. Veit6 C. Schöb et al.
  • 1Inst. of Geography, Univ. of Bern, Hallerstrasse 12, 3012 Bern, Switzerland
  • 2Biology Dept., Univ. of Teacher Education, Gertrud-Woker-Strasse 5, 3012 Bern, Switzerland
  • 3568 Environmental Bldg., Univ. of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, 2778653 Chiba, Japan
  • 4Laboratoire d’Ecologie Alpine UMR 5553 UJF-CNRS and Station Alpine J. Fourier UMS 2925 UJF-CNRS, Univ. of Grenoble, 38041 Grenoble, France
  • 5CSIRO Marine and Atmospheric Research, P.O. Box 1666, Canberra, 2601, Australia
  • 6Inst. of Geography, Univ. of Bern, Hallerstrasse 12, 3012 Bern, Switzerland

Abstract. Alpine snowbeds are characterised by a very short growing season. However, the length of the snow-free period is increasingly prolonged due to climate change, so that snowbeds become susceptible to invasions from neighbouring alpine meadow communities. We hypothesised that spatial distribution of species generated by plant interactions may indicate whether snowbed species will coexist with or will be out-competed by invading alpine species – spatial aggregation or segregation will point to coexistence or competitive exclusion, respectively. We tested this hypothesis in snowbeds of the Swiss Alps using the variance ratio statistics. We focused on the relationships between dominant snowbed species, subordinate snowbed species, and potentially invading alpine grassland species. Subordinate snowbed species were generally spatially aggregated with each other, but were segregated from alpine grassland species.

Competition between alpine grassland and subordinate snowbed species may have caused this segregation. Segregation between these species groups increased with earlier snowmelt, suggesting an increasing importance of competition with climate change. Further, a dominant snowbed species (Alchemilla pentaphyllea) was spatially aggregated with subordinate snowbed species, while two other dominants (Gnaphalium supinum and Salix herbacea) showed aggregated patterns with alpine grassland species. These dominant species are known to show distinct microhabitat preferences suggesting the existence of hidden microhabitats with different susceptibility to invaders.

These results allow us to suggest that alpine snowbed areas are likely to be reduced as a consequence of climate change and that invading species from nearby alpine grasslands could outcompete subordinate snowbed species. On the other hand, microhabitats dominated by Gnaphalium or Salix seem to be particularly prone to invasions by non-snowbed species.

Publications Copernicus
Download
Citation
Share