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Characterization of Spatial Heterogeneity in Transpiration from Different Spruce Stands
BITÖK-W 4From 01/1995 to 06/1996
Principal Investigator: John Tenhunen
Staff: Martina Alsheimer
Grant: 0339476 B Vorhersage und Erklärung des Verhaltens und der Belastbarkeit von Ökosystemen unter veränderten Umweltbedingungen
Tree canopy transpiration was measured at five Norway spruce stands at the Lehstenbach catchment
(Fichtelgebirge) throughout the entire vegetation period of 1995. The investigated stands differed in age and
structure, in exposition, or in soil characteristics. The seasonal pattern of tree transpiration was similar to those
measured at three of the stands in 1994 but in 1995 the yearly sum was on average approx. 12% less than in
the previous year. Among the stands, clear differences in tree canopy transpiration were observed. The highest
transpiration rates (208 mm year-1) were observed at a 40-year-old stand growing on boggy soil and the tree
transpiration decreased with increasing age of the stands. The lowest transpiration rates (90 mm year-1) were
estimated for the trees of a 140-year-old stand investigated by Dr. B. Köstner. By the comparison of all
investigated stands correlations were found between tree canopy transpiration and stand age and between tree
canopy transpiration and tree density in the stands, which enable an estimation of whole watershed tree
transpiration.
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