Six European beech (Fagus sylvatica L.) provenances (2x Germany, Austria, Romania, Spain and Czech Republic) were investigated at the study site Schadtbek near Kiel (Schleswig-Holstein) during the growing seasons of 2006 and 2007. Aim of the investigation was to study the influence of drought stress on ecophysiological growth parameters and water consumption under field conditions. We measured electron transport rates, effective quantum yield, transpiration and leaf conductance for water vapor under different environmental conditions. The comparison of mean values of these parameters shows not only between but also within different provenances significant differences between the repeats and between the years. In almost all provenances a positive relationship between electron transport rates and leaf conductance could be observed. Furthermore, trees from SE Europe seem to react more sensitively to low air humidity. The reduction of stomata opening minimizes water consumption, especially on hot days with high water vapor pressure deficits. The ecophysiological performance of the trees emphasise the high adaptation and adaptability of the beech to climate conditions on the level of populations. Significant differences between populations can be identified on the basis of the measured variables only occasionally and then usually they affect only the extreme values. Therefore, the use of putative better to future climates adapted provenances is to see critically.
Kriebitzsch, WU; Veste, M
Importance of dry summer for photosynthesis and transpiration of different provenances of beech (Fagus sylvatica L.)
Landbauforschung-Journal Of Sustainable And Organic Agricultural Systems