ECOSYSTEM WATER USE EFFICIENCY OF NORWAY SPRUCE MONOCULTURE FROM EDDY-COVARIANCE AND ECOPHYSIOLOGICAL MEASUREMENTS

Water release and biomass production of young Norway spruce stand were investigated by different approaches during 2004-2009. Closed-path eddy-covariance system (LI-7000) was found to be suitable for accurate net ecosystem production evaluation (NEP). NEP was in a good correspondence with the biomass inventory data.
In contrary, water vapour eddy-covariance fluxes were found underestimating a real water release of the stand.
Global radiation and air water vapour pressure deficit at 75% of the stand height were main micrometeorological control drivers for stand transpiration (T) and evapotranspiration (ET). Thus, missing or bad quality data of eddy-covariance ET can be simulated according to these parameters.
Water use efficiency (WUE) values calculated from net and gross primary production data highly differed in absolute values as well as in seasonal course mainly due to respiration.
Annual WUE values from eddy-covariance and from ecophysiological measurements of T and stand biomass increment were unfortunately incomparable.
Therefore, precise research of eddy-covariance H2O fluxes and WUE evaluation need to continue.

VIII International Symposium on Sap Flow

R. Pokorný, R. Slípková, K. Havránková, M. Pavelka

eddy-covariance, evaporation, Picea abies, sap flow, transpiration

https://doi.org/10.17660/ActaHortic.2012.951.36