And then add more compexity. We will start simply and then add more complexity. Models are an abstract conceptualization of how we think an ecosystem works. Architects build physical or computer models of their buildings to understand how they will work. Mechanical engineers design computer models of car engines to test how different designs may affect performance and reliability.
Chemists use reaction diagrams to predict reactions in a test tube.
Similarly, ecologists use mathematical descriptions of the transfer of matter throughout the ecosystem to understand how ecosystems work. For example, if we have a decomposition model describing the amount of litter on the forest floor that includes the variables temperature and litter quality, we can determine how changes in temperature affect the amount of material remaining. Suppose I gave you 100 grams of dried prairie plant material and asked you to put it in the Arb. Now I ask you how much of that material will be there in 50 years. If you were really hard core, you could come back to the Arb in 50 years and measure it.