Factors Controlling Species Richness in Alpine Plant Communities: An Assessment of the Importance of Stress and Disturbance
Publisher DOI
Abstract
This study explores whether the high variability of vascular plant diversity among alpine plant communities can be explained by stress and/or disturbance intensities. Species numbers of 14 alpine plant communities were sampled in the Swiss Alps. To quantify the intensity of 13 stress and 6 disturbance factors potentially controlling plant life in these communities, a survey was conducted by asking numerous specialists in alpine vegetation to assess the importance of the different factors for each community. The estimated values were combined in stress- and disturbance-indices which were compared with diversity according to the Intermediate Stress Hypothesis, the Intermediate Disturbance Hypothesis, and the Dynamic Equilibrium Model, respectively. Each of these theories explained a part of the variability in the species richness, but only the Dynamic Equilibrium Model provided a complete and consistent explanation. The last model suggests that community species richness within the alpine life zone is generally controlled by stress intensity. Disturbance and competition seem to play a secondary role by fine-tuning diversity in specific communities. As diversity is primarily limited by stress, a moderation of temperature-related stress factors, as a result of global warming, may cause a shift of the equilibrium between stress, disturbance, and competition in alpine ecosystems.
Date Issued
2002-11
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Kammer, Peter M. |
Additional Credits
Journal
Arctic, Antarctic, and Alpine Research
Publisher
Institute of Arctic and Alpine Research, University of Colorado at Boulder
ISSN
1523-0430
Access(Rights)
restricted