Bottom-up ecology: an agent-based model on the interactions between competition and predation

Istvan Karsai, Emil Montano, Thomas Schmickl
Letters in Biomathematics (2016)


We developed an agent-based computer model of an ecosystem to predict interactions of competition and predation. In our simulations
of the model, the effects of the ‘Gause law’ emerged as the results of population fluctuations and a large number of stochastic events. Small
biases in life history parameters produced strong effects through the interactions of positive feedback with the population fluctuations.
In a low-production environment, the smaller and faster consumer outcompetes the larger and slower one, but in a high production
environment the larger and slower consumer survives. Predation hastens the extinction of one of the consumers, but niche partitioning
of the consumers increases both the coexistence of consumers and the number of predators. Predators with medium efficiency are able
to coexist in the system longer and in larger numbers. Besides the ecological insights this model provides, we conclude that agentbased
simulations are very effective tools to explore the interactions between predation and competition interactions.

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