Slide 5: A 'reduced form' ecosystem model for savannas under climate change
Ecosystem models can often be very complicated, requiring hundreds of parameters. Can we make a simple one, just for African savannas, that is nevertheless realistic in its main features? This is called a 'reduced form' model.
The functional types for this system are obviously restricted to those occurring within the savanna region, but they were significantly expanded beyond the generic global types. This model includes the effects of temperature, rainfall, seasonality, carbon dioxide, soil texture, fire regimes and megaherbivores. The equations used to integrate these are "quasi-mechanistic" in nature. That is, they are simple , reduced forms of the mechanistic processes that work within plants, and describe the emergent properties that are observed at an ecosystem scale. The model was run with a timescale step of a single year (hence seasonal effects were implied within the model but not actually calculated separately), and the spatial scale of the model was a "patch" of land.