Modelling of ion dynamics in the rhizosphere of forest tree roots

For a better understanding of the matter dynamics at the root-soil interface many model approaches of the process dynamics in the rhizosphere have been developed. They usually describe the transport of a special substance (ions, protons, soluble carbon components) by a diffusion-convection equation and go back to the classical model approach of Nye and Marriott (1969) and are extended, in some cases, by source or sink terms to account for simultaneous matter transformations (e.g. due to microbial activity) in combination with root induced uptake or excretion of those substances (Nye and Tinker, 1977; Nye, 1981; Newman and Watson, 1977; Barber, 1984; Darrah, 1991 among others).