A simulation model is proposed, describing vegetation dynamics in a bunchgrass paramo ecosystem, in relation to cattle grazing and burning. Field-work was conducted in Parque Nacional Natural Los Nevados, Colombia, at elevations of 3900-4200m. Three successive stages of vegetation development are recognised in relation to grazing: an opening phase of the bunchgrass layer, conditionally followed by an invasion of short grasses, and eventually a degeneration stage of vegetation where severe erosion may occur. Test runs of the model, based on analysis of data collected in a small pilot area, were executed with an arbitrary set of parameters. These simulations produced realistic results. The proposed model serves as a tool for identification and analysis of processes, significant to the management of bunchgrass paramo ecosystems.
