An evaluation of the state factor model of soil ecosystems

Abstract

Hans Jenny's conceptual equation describing soil ecosystems as a function of five state factors (time, climate, parent material, topography, and biota) has never been solved. The interdependence of the state factors and the difficulty in quantifying some factors have been considered the primary obstacles to a solution. The problem is reevaluated because qualitative systems analysis methods are available which can overcome both these obstacles. Qualitative asymptotic stability analysis supports previous suggestions that a general, comprehensive solution of Jenny's equation is not possible. The obstacles to such a solution are the multiple time scales over which state factors operate, and the difficulty of combining internal, external and temporal components of the soil ecosystem into a single model, rather than quantification and factor interdependence problems. Future applications of the state factor model should utilize the model's general form, based on energy and matter fluxes in the soil ecosystem.