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Environmental Processes Affecting the Greenhouse Gas Budget of Grasslands in an Elevational Transect in Switzerland
Einfluss der Umweltbedingungen auf die Treibhausgasbilanz

Project Number: 200021-105949

Project Type:	Research_Project
Project Duration:	02/01/2005 - 01/31/2008 project completed
Funding Source:	SNSF ,
Leading Institution:	ETH Zürich, Dept. Umweltsystemwissenschaften, D-USYS, Institut für Agrarwissenschaften, IAS
Project Leader:	Herr Werner Eugster verstorben delete

related to this project.

for which the project has a relevance.

Research Areas:

Biodiversity

Disciplines:

other areas of environmental sciences

Keywords:
nitrous oxide emissions, methane emissions, methane oxidation, carbon dioxide exchange, isotopic discrimination, eddy covariance flux measurements, flux partitioning with stable isotopes, biodiversity

Abstract:
The most important greenhouse gases from agricultural areas are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The high share of agricultural emissions that contribute 72% and 63% to the total Swiss emissions of N2O and CH4, respectively, require a more detailed understanding of the processes governing those greenhouse gas fluxes. Particularly in grasslands, where N2O fluxes are known to be relevant, and where CH4 may be taken up via oxidation, or be released when soils are water saturated. The motivation for the proposed research has emerged during the record-breaking summer of 2003 which according to our preliminary understanding was not exceptional in many parts of the pre-Alps where grassland yields were rather good. This is in contrast to the situation experienced in the low altitudes of the Swiss Plateau where a significant drought affected agricultural yields dramatically, leading to severe economic losses for lowland farmers.
Working Hypotheses

Our working hypothesis is thus that a changing climate of the type suggested by the summer of 2003 could potentially revive the economic importance of pre-Alpine and Alpine agriculture, namely in relation to lowland farming which revealed to be much more vulnerable to such extremes in climate. In order to understand the implications that such modifications of environmental conditions could have on the national greenhouse gas budget we suggest to quantify the N2O and CH4 fluxes over grassland in combination with continuous CO2 exchange measurements. We also hypothesize that if CH4 is oxidized by the grassland soils around cattle farms, then we should be able to find a close relation between the measured CH4 emissions from cattle and the CH4 uptake that we propose to measure here.
Experimental Design and Methods

We take benefit of the unique opportunities given by the three ETH Research Stations at 400, 1000, and >1900 m a.s.l., which provide a representative transect for the Swiss three-step system of Alpine summer grazing. We suggest to measure N2O and CH4 fluxes continuously with the eddy covariance method at the lowest elevation site. CO2 exchange and associated energy fluxes will be continuously measured at the two lower stations.
At all three sites we plan to carry out additional stable isotope (13C and 18O) sampling campaigns to study the most relevant biogeochemical processes that are active during the growing season, and at the lowest site also in winter. These data will enable us to partition net CO2 fluxes obtained with eddy covariance into the process components assimilation and respiration. This will allow us to assess the carbon turnover of the grassland ecosystems.

Publications:
Zeeman, M.J. , Hiller, R., Gilgen, A.K., Michna, P., Plüss, 2010. Management, not climate, controls net CO 2 fluxes and carbon budgets of three grasslands along an elevational gradient in Switzerland. - Agric. Forest Meteorology 50, 519–530

Zeeman, M.J. 2008. Environmental processes affecting the carbon dioxide budget of grasslands along an elevational gradient in Switzerland - Swiss Federal Institute of Technology in Zurich (ETHZ), dissertation, Nr. 18138
pdf Abstract

Source of Information: NF Import 2005


Last update: 8/11/22
Source of data: ProClim- Research InfoSystem (1993-2024)
Update the data of project: CH-105949

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