INTERCEPTION IN A MOUNTAINOUS DECLINING SPRUCE STAND IN THE STRENGBACH CATCHMENT (VOSGES, FRANCE)

In a over-mature (declining) 90-year-old Norway spruce stand (Picea abies) in the Vosges mountain area, gross precipitation, throughfall, stemflow and meteorological variables have been measured for three periods in the summers of 1988, 1989 and 1990; transpiration was measured from June to August 1989. Throughfall, interception and stemflow represent, respectively, 65.3%, 34.2% and 0.5% of the incident rainfall. A semi-logarithmic relationship between interception and gross precipitation is given. Transpiration of the stand determined by sap-flow measurements represents only 27% of the potential evapotranspiration. Evaporation of water intercepted by the vegetation is the major component of the evapotranspiration.