These are a series of three modules built around a crippled version of a program called Extend. Extend seems to be a program somewhat like Stella (see review). Using the version of Extend included, you can run three different models, one of a grasslands ecosystems with fires, a second looking at logging, and a third looking at fishing. Each model has functional blocks representing things like trees, fire, logging effort, and cash. You are asked to connect the blocks together to make ecosystems, and then to connect these ecosystems to human management systems. The manual takes you through this process step-by-step. You can then play with changing selected parameters of each block, and running the model to see what happens to population sizes (or the equivelant variable) in each component of the system over time. The authors of these models want students to focus on the process of model building, and how you calibrate and use models, rather than on the models themselves, so all the parameters for each block are easily available to be played with, and the equations connecting the blocks are not shown from within the program.

The models which the authors have developed are nice, and should be useful in a course looking at the interactions between people and ecosystems. The software makes it fairly easy to change parameters and add and remove links between things, though there are a lot of extraneous tools and commands that could potentially confuse non-computer literate students. However, in more than an introductory class, or if the instructor would like to modify these models instead of using them as is, then I think it would be better to go with a full-blown modelling program such as Stella, or perhaps the full version of Extend.

Computer: Macintosh

Source: BioQuest

Cost: Low (single user) / High (site license)

Last update 22nd of January 1996