Category Archives: chapter 3

3.6 grass – bush – trees IPS succession model

This model is an implementation of the simple grass – bush – trees model of

Durrett R and Swindle G 1991 Are there bushes in a forest?. Stochastic Processes and their Applications, 37, 19–31.

Click on the image to download and save the model NetLogo file. You will need to install NetLogo to run this file.

3.5 Competing contact processes

This is an implementation of competing contact processes in two dimensions, including an option for one of the processes to spread over long distances. Models of this kind are discussed in

Durrett R and Levin SA 1994b Stochastic spatial models: a user’s guide to ecological applications. Philosophical Transactions of the Royal Society of London. Series B. 343, 329-350.

Click on the image to download and save the model NetLogo file. You will need to install NetLogo to run this file.

3.4 Basic two dimensional contact process

This is an implementation of a basic contact process in two dimensions. The contact process is one of the simplest possible interacting particle systems. It is discussed in some detail in

Durrett R and Levin SA 1994b Stochastic spatial models: a user’s guide to ecological applications. Philosophical Transactions of the Royal Society of London. Series B. 343, 329-350.

Click on the image to download and save the model NetLogo file. You will need to install NetLogo to run this file.

3.3 Totalistic automata

This model allows you to explore the behaviour of a wide variety of possible totalistic automata, i.e., cellular automata whose rules are based only on the total number of cells in each neighbourhood in each of the two allowed states.

An example is the majority rule automaton which you can see running in the video.  Here the rule is that each cell adopts the state that is in the majority in its neighbourhood at the next time step.

Click on the image to download and save the model NetLogo file. You will need to install NetLogo to run this file.