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Scale dependent nitrogen dynamics in forests
BMBF PT BEO 51-0339476 C BITÖK-N17From 07/1996 to 12/1997
Principal Investigator: Bernd Huwe
Staff: Andreas Gaßner, Hans Piehler, Kai Uwe Totsche
Grant: 0339476 B Vorhersage und Erklärung des Verhaltens und der Belastbarkeit von Ökosystemen unter veränderten Umweltbedingungen
The problem of the scale dependency of transport processes is traced back to the action of the variability of parameters on the microscale, e.g. the hydraulic conductivity or the adsorption constant of transport processes. Since the variability of these parameters is not introduced explicitly into the transport equations, it is hidden in the effective transport parameters the solute transport is described with usually. Considering the variability of the parameters explicitly in the transport equation it can be shown quantitatively how the fluctuations of the parameters bring about the so called scale effect on large scales. For this purpose methods from perturbation theorie and renormalization theory are used, and it is shown with 2 examples, how the variability of the adsorption constant affects the transport on large scales.
Herewith the hypotheses IV, V, and VII of the research proposal are investigated, and the consequences of a change of scales are presented in an exemplary fashion.