PARENT SESSION
Contributed Oral Session 93: Modeling: Movement, Populations, and Communities
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 513 E, Level 5, Palais des congrès de Montréal
Modeling resource competition in plants without numbers: simulations based on qualitative reasoning.
Nuttle, Tim*,1, Bredeweg, Bert2, Salles, Paulo3, 1 Institute of Ecology, Jena, Germany2 Human Computer Interactions Lab, Amsterdam, The Netherlands3 Institute of Biological Sciences, Brasilia, Brazil
ABSTRACT- Understanding how plants extract resources and use them to support growth has important implications for understanding subsequent processes, including population dynamics of plants, competition for limiting resources by different species, and population dynamics of herbivores and predators. We developed a qualitative model based on Tillman's R* model of plant exploitation of resources. The model uses qualitative reasoning, a technique from artificial intelligence that facillitates reasonaing about cause and effect based on logic about relative values and direction of change rather than numerical information. Because such models are based on explicit causal representations, they can be used to generate explanations of causal behavior produced by simulations. This feature not only helps us understand the interactions among multiple processes within our model, but also facillitates communication about the modeled system to others, for example to students and decision makers. We provide a brief background to qualitative reasoning, show how our model of plant growth based on resource competition is represented with qualitative reasoning, and show how the model was used to run simulations investigating the effect of limiting resources on plant community dynamics in specific systems. We also discuss some further model developments that should allow the model to be expanded to investigate how food chains and food webs are ultimately limited by resource supply.
Key words: resource competition, plant community dynamics, qualitative reasoning