Co-ordinating Editor: A. Chiarucci
Species-specific stomatal response of trees to drought – a link to vegetation dynamics?
Article first published online: 29 APR 2009
© 2009 International Association for Vegetation Science
Journal of Vegetation Science
Volume 20, Issue 3, pages 442–454, June 2009
How to Cite
Zweifel, R., Rigling, A. and Dobbertin, M. (2009), Species-specific stomatal response of trees to drought – a link to vegetation dynamics?. Journal of Vegetation Science, 20: 442–454. doi: 10.1111/j.1654-1103.2009.05701.x
- Issue published online: 20 MAY 2009
- Article first published online: 29 APR 2009
- Received 11 February 2008;Accepted 21 October 2008.
- climate change;
- species competition;
- stomatal regulation;
- tree water relations;
- vegetation dynamics
Question: Is stomatal regulation specific for climate and tree species, and does it reveal species-specific responses to drought? Is there a link to vegetation dynamics?
Location: Dry inner alpine valley, Switzerland
Methods: Stomatal aperture (θE) of Pinus sylvestris, Quercus pubescens, Juniperus communis and Picea abies were continuously estimated by the ratio of measured branch sap flow rates to potential transpiration rates (adapted Penman-Monteith single leaf approach) at 10-min intervals over four seasons.
Results: θE proved to be specific for climate and species and revealed distinctly different drought responses: Pinus stomata close disproportionately more than neighbouring species under dry conditions, but has a higher θE than the other species when weather was relatively wet and cool. Quercus keeps stomata more open under drought stress but has a lower θE under humid conditions. Juniperus was most drought-tolerant, whereas Picea stomata close almost completely during summer.
Conclusions: The distinct microclimatic preferences of the four tree species in terms of θE strongly suggest that climate (change) is altering tree physiological performances and thus species-specific competitiveness. Picea and Pinus currently live at the physiological limit of their ability to withstand increasing temperature and drought intensities at the sites investigated, whereas Quercus and Juniperus perform distinctly better. This corresponds, at least partially, with regional vegetation dynamics: Pinus has strongly declined, whereas Quercus has significantly increased in abundance in the past 30 years. We conclude that θE provides an indication of a species' ability to cope with current and predicted climate.