Fachdokumente Online der Landesanstalt für Umwelt Baden-Württemberg

zur LUBW   zum Ministerium für Umwelt, Klima und Energiewirtschaft   zum Ministerium für Ländlichen Raum und Verbraucherschutz   zum Ministerium für Verkehr und Infrastruktur  

Magnesium-deficiency in Norway spruce – Influence of early summer drought and dolomitic liming.
Subproject A: Water and nutrient supply of the spruces.
Subproject B: Soil water, rooting, and nutrient dynamics.

Summary

Starting-point of the project were calculations that severe droughts in early summer during the years 1976 and 1983 may have triggered the origin of magnesium deficiency symptoms in Norway spruces growing at high altitudes in the Southern Black Forest. In order to experimentally verify this hypothesis, two temporary roofs were installed in spring 1997 on two sub-parcels of the ARINUS-project (control and dolomitic liming). Thus, during the period May – July of the years 1997 and 1998, a desiccation of the upper soil horizons could be induced. Subsequently, the roofs were removed again in each case in order to avoid artefacts. Besides the parameters of soil water dynamics and litter decay, radial changes in stem diameter and xylem flows were measured in the trees on the control and experimental plots. As yet, no significant changes in the magnesium contents of needles could be detected, but such effects are only to be expected in the next 2 – 3 years, due to the known delay effects. The accompanying analyses are therefore continued.

 


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