Leaf and ecosystem response to soil water availability in mountain grasslands
- Resource Type
- Authors
- Lukas Hörtnagl; Federico Brilli; Georg Wohlfahrt; Albin Hammerle; Francesco Loreto; Armin Hansel; Alois Haslwanter
- Source
- Agricultural and forest meteorology
151 (2011): 1731–1740.
info:cnr-pdr/source/autori:Brilli F., Hörtnagl L., Hammerle A., Haslwanter A., Hansel A., Loreto F., Wohlfahrt G./titolo:Leaf and ecosystem response to soil water availability in mountain grasslands/doi:/rivista:Agricultural and forest meteorology (Print)/anno:2011/pagina_da:1731/pagina_a:1740/intervallo_pagine:1731–1740/volume:151
- Subject
- Atmospheric Science
Global and Planetary Change
geography
geography.geographical_feature_category
Drought
Evapotranspiration
Ecology
food and beverages
Climate change
Forestry
Graminoid
Article
Grassland
Water resources
Montane ecosystem
Agronomy
Soil water
Forb
Environmental science
Ecosystem
Photosynthesis
Agronomy and Crop Science
- Language
- ISSN
- 0168-1923
Climate change is expected to affect the Alps by increasing the frequency and intensity of summer drought events with negative impacts on ecosystem water resources. The response of CO 2 and H 2 O exchange of a mountain grassland to natural fluctuations of soil water content was evaluated during 2001–2009. In addition, the physiological performance of individual mountain forb and graminoid plant species under progressive soil water shortage was explored in a laboratory drought experiment. During the 9-year study period the natural occurrence of moderately to extremely dry periods did not lead to substantial reductions in net ecosystem CO 2 exchange and evapotranspiration. Laboratory drought experiments confirmed that all the surveyed grassland plant species were insensitive to progressive soil drying until very low soil water contents ( 3 m −3 ) were reached after several days of drought. In field conditions, such a low threshold was never reached. Re-watering after a short-term drought event (5 ± 1 days) resulted in a fast and complete recovery of the leaf CO 2 and H 2 O gas exchange of the investigated plant species. We conclude that the present-day frequency and intensity of dry periods does not substantially affect the functioning of the investigated grassland ecosystem. During dry periods the observed “water spending” strategy employed by the investigated mountain grassland species is expected to provide a cooling feedback on climate warming, but may have negative consequences for down-stream water users.