Response of temperate grasslands at different altitudes to simulated summer drought differed but scaled with annual precipitation

Gilgen, Anna Katarina; Buchmann, Nina (2009). Response of temperate grasslands at different altitudes to simulated summer drought differed but scaled with annual precipitation. Biogeosciences, 6(11), pp. 2525-2539. Göttingen: Copernicus Publications 10.5194/bg-6-2525-2009

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Water is an important resource for plant life. Since climate scenarios for Switzerland predict an average reduction of 20% in summer precipitation until 2070, understanding ecosystem responses to water shortage, e.g. in terms of plant productivity, is of major concern. Thus, we tested the effects of simulated summer drought on three managed grasslands along an altitudinal gradient in Switzerland from 2005 to 2007, representing typical management intensities at the respective altitude. We assessed the effects of experimental drought on above- and below-ground productivity, stand structure (LAI and vegetation height) and resource use (carbon and water). Responses of community above-ground productivity to reduced precipitation input differed among the three sites but scaled positively with total annual precipitation at the sites (R2=0.85). Annual community above-ground biomass productivity was significantly reduced by summer drought at the alpine site receiving the least amount of annual precipitation, while no significant decrease (rather an increase) was observed at the pre-alpine site receiving highest precipitation amounts in all three years. At the lowland site (intermediate precipitation sums), biomass productivity significantly decreased in response to drought only in the third year, after showing increased abundance of a drought tolerant weed species in the second year. No significant change in below-ground biomass productivity was observed at any of the sites in response to simulated summer drought. However, vegetation carbon isotope ratios increased under drought conditions, indicating an increase in water use efficiency. We conclude that there is no general drought response of Swiss grasslands, but that sites with lower annual precipitation seem to be more vulnerable to summer drought than sites with higher annual precipitation, and thus site-specific adaptation of management strategies will be needed, especially in regions with low annual precipitation.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Plant nutrition (discontinued)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Gilgen, Anna Katarina and Buchmann, Nina

Subjects:

500 Science > 580 Plants (Botany)
500 Science > 570 Life sciences; biology
500 Science > 590 Animals (Zoology)

ISSN:

1726-4170

Publisher:

Copernicus Publications

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

04 Oct 2013 15:21

Last Modified:

10 Dec 2014 06:38

Publisher DOI:

10.5194/bg-6-2525-2009

Web of Science ID:

000272232200012

BORIS DOI:

10.7892/boris.36293

URI:

https://boris.unibe.ch/id/eprint/36293 (FactScience: 204297)

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