Document: CAR-3-99-123

Effects of species and functional diversity of plants on ecosystem functioning: Preliminary results of a removal experiment.

URCELAY, C.R.* ¹, D.E.GURVICH ¹, S.M.DÍAZ ¹, E.CUEVAS ² and F.S.CHAPIN III ³

Instituto Multidisciplinario de Biologia Vegetal, Univ. Nac. de Córdoba, Argentina ¹
Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela ²
University of Fairbanks, Alaska, USA ³

Abstract:
We have established a long-term removal experiment on the effects of plant taxonomic and functional diversity on ecosystem functioning of a natural shrubland of central Argentina. The treatments applied were: 1) control, without physical disturbance and plant removal; 2) control with physical disturbance of soil without plant removal, and 3) removal of shrubs (perennial forbs, graminoids, annual forbs), and removal of the dominant species of each functional type (Acacia caven, Salvia pallida, Stipa eryostachia and Bidens subalternans), respectively. In order to assess possible changes in ecosystem functioning, we monitored soil temperature and community patterns of plant and mycorrhizal communities. In the first year after removal we found no invasion by native or exotic species which were not present before manipulation under any of the treatments. We found that vesicular-arbuscular mycorrhizal infection was significantly higher in control plots than in any of the treatments, including disturbed control plots. Maximum daily soil temperature was higher in the shrub removal treatments.

Keywords: Argentina

This abstract is being presented at: 10:30 AM in session:
Poster Session #12: Disturbance Ecology.