Greenhouse gases, CO2, H2O and energy exchange of mountain grasslands
The overarching objective of this project is to quantify and understand the variability of the CO2, H2O and energy exchange of mountain grassland ecosystems as affected by land use and climate. To this end we quantify these exchange processes by means of the eddy covariance method in the field, as well as use models to interpret, understand and extrapolate these flux measurements.
The study sites selected to this end (map) are situated along gradients in land use (extensively to intensively managed hay meadows) and climate (low to high elevations) naturally occurring in Tyrol/Austria. The site with the longest data record is Neustift, where flux measurements initiated 2001 during the EU FP 5 project CarboMont and continue since then within the frame of several nationally funded projects. The results from Neustift have been published in several recent papers (Wohlfahrt, 2004; Wohlfahrt et al., 2005a,b; Gilmanov et al., 2007; Hammerle et al., 2007) and may be downloaded from the CarboEurope IP data base. Since December 2007 we are conducting continuous flux measurements at Rotholz, which due to the lower elevation and the resultant longer growing period is managed more intensively than Neustift. In addition, we have been conducting periodic flux measurements, using a mobile eddy covariance system at several other sites: The flux measurements at Kaserstattalm were conducted during 2003 and aimed at testing the applicability of the eddy covariance method on a steep slope (Hammerle et al., 2007) and at analysing the effects of grassland management and climate typical for high‑elevation meadows on their net ecosystem carbon balance (Wohlfahrt et al., submitted). During 2005‑2007 a total of four different sites were investigated with our mobile eddy covariance system (Fügen, Scharnitz, Leutasch and Längenfeld) aiming at elucidating the magnitude of and controls on the spatial variability of the CO2, H2O and energy exchange of mountain grassland ecosystems, and thus ultimately the representativeness of our long‑term flux measurements at Neustift.
Since spring 2010 were are quantifying also the fluxes of CH4 and N2O by means of the eddy covariance method within the frame of the EU project GHG Europe.
Funding for this project was/is provided by:
EU
FWF
TWF
ÖFG
ÖAW