HUMOD - the model of soil organic matter dynamics in the natural and land-used ecosystem

摘要

The article describes the model of soil organic matter (i.e. humus) formation and dynamics in the various soil types in natural ecosystems as well as under the impacts of agricultural land-use. The main purpose of the elaborated model HUMOD is to evalaute the major driving forces and controls over soil organic matter content and to predict regional patterns of humus in range and cultivated soils. The model is highly-aggregated and process-based. The model is constructed on the basis of response functions method that describes the relationships between soil organic matter content and main driving forces of its formation. For the evaluation of parameters and testing of the model we obtained data for 75 soil types and subtypes of main CIS regions from tundra up to desert exosystems. The special erosion submode calcualtes the added losses of humus due to water and wind erosion. The main practices of agricultural land use resulting in the changes of humus dynamics are demonstrated as simulation experiments.