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Predator-Prey Model. A Systems Dynamics Approach. Introduction. Predator-prey models are arguably the building blocks of the bio- and ecosystems as biomasses are grown out of their resource masses.
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Predator-Prey Model A Systems Dynamics Approach
Introduction • Predator-prey models are arguably the building blocks of the bio- and ecosystems as biomasses are grown out of their resource masses. • Species compete, evolve and disperse simply for the purpose of seeking resources to sustain their struggle for their very existence. • Depending on their specific settings of applications, they can take the forms of resource-consumer, plant-herbivore, parasite-host, tumor cells (virus)-immune system, susceptible-infectious interactions, etc. (Scholarpedia)
Elements of the Model Grass Rabbit Wolf AREA
Grass Model (Grass) Death rate grass grass eaten by rabbits natural death TIME STEP c density grass nom Grass i Grass i Area (Grass) grass untouched Spread rate grass natality grass
Explanation • As the amount of grass increases, so does the number of rabbits. • When grass is low, rabbit population also becomes low – which means not enough food to support the wolves. • As the secondary predator (the wolves) would dramatically increase in population, and then crash hard when the primary predator (the rabbits) were nearly extinct. • Then, the rabbits would go around eating and reproducing, while the wolves would catch up, after nearly going extinct themselves.
Explanation • The danger is when either population fluctuates so much that population dips down to zero. • The wolves will almost completely cut off the rabbits’ food supply. Grass Rabbit Wolf AREA
Internet Sources • http://www.cs.uwyo.edu/~wspears/courses/CS5010/frey/rabbits.pdf • http://www.scholarpedia.org/article/Predator-prey_model