This program lets you play around with differential equation models in ecology. It is very different, however, than some of the other ecology programs listed here in that it lets you mix and match classical ecological equations with each other to make systems of equations. This works as follows. You can have up to 10 different species and/or ecosystem components. Each species has an equation which governs its growth and death, for instance exponential, logistic, lotka-volterra, and so on. You may also add in interactions between the species, such as specifying one of the species as a predator on another one, again governed by classical differential or differencce equations. Each equation has a set of parameters that you can set. You then run the models and watch population sizes over time of each species. You can also sample the populations using a couple of sampling techniques, and you can specify that the sampling include error to simulate real life sampling.

In addition, the program lets you add in a spatial component to the models, by having separate populations of each species in distinct spatial areas. You can have up to 200+ spatial areas, and in each one you can independently specify starting conditions. You can then specify how migration will occur between each pair of cells for each species cells. The program will give you separate population size graphs for each area when you run the model, so you can look at metapopulation dynamics, island biogeography, etc..

The user interface for Biota is particularly well-designed, given the complexity of the program, and lets you easily change equations and parameters through pop-up menus, dialogs, and maps of the different areas. Because of the ability to mix and match equations, species, and areas, you should be able to use this program to design and play with models demonstrating many concepts, from simple population growth models to moresophisticated concepts involving space and several interacting species. Nevertheless, I would be hesitant to use this in an introductory class, because despite the nice user interface the level of understanding you need to figure out what is going on is still fairly high. There are a lot of equations and interactions to keep track of, and you need to understand these at least superficially to be able to play with parameters, and interpret the graphs of population size in light of those parameters. Building new models that are stable is also not trivial. So I think this program would best be used in more advanced ecology courses, where either you want students to be able to play with models but do not want to use a full-blown modelling program such as Stella or Mathematica, or you want to be able to play with spatially-explicit models.

Computer: Macintosh

Source: BioQuest

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

Last update 22nd of January 1996