Simulation modelling of fynbos ecosystems: Systems analysis and conceptual models

Abstract

This report outlines progress with the development of computer based dynamic simulation models for ecosystems in the fynbos biome. The models are planned to run on a portable desktop computer with 500 kbytes of memory, extended BASIC language, and advanced graphic capabilities. The FYNBOS model, which simulates seasonal ecosystems dynamics, is the central model of the Project. This model consists of 14 submodels of major ecosystem processes: climate; soil water balance; energy balance; decomposition; nitrogen cycling; phosphorus cycling,* uptake of water and nutrients by roots; carbon balance; growth and demography of shrubs, growth and demography of graminoids; growth and demography of geophytes; seedling growth; propagule dynamics; and plant-animal interactions. An additional two models, which expand aspects of the FYNBOS model, are described: a model for simulating canopy processes; and a Fire Recovery Simulator. The canopy process model will simulate ecophysiological processes in more detail than FYNBOS over a one day time period. The Fire Recovery Simulator models successional dynamics after disturbance with less ecophysiological detail than FYNBOS, over periods of decades and longer.