Biology Simulations offers two simulations that can be used for virtual labs that practice calculating diversity or richness. The Biodiversity simulation produces a community of organisms each time the "Produce Community" button is clicked. The virtual labs associated with this compare two separate runs of the simulation. You can find more specific information about this simulation in this blog post. The Macroinvertebrates simulation features two rivers. The simulation "collects" macroinvertebrates from each river. More information about the simulation is in this post. Students can compare the two rivers based on a variety of factors, including diversity and richness.
The Resources page (Word documents, most suitable for printing) and Google Drive (Google docs, designed for paperless use) both have multiple worksheets that are available to study biodiversity using these two simulations. This post will outline the various options.
The simplest option available for the Biodiversity simulation is the basic species richness version of the lab. This is just comparing the number of animal species in the community and would be appropriate for younger students or students who aren't ready for using equations with multiple components. There is not a species richness version of the virtual lab for the Macroinvertebrates simulation, but it could certainly be used in the same way.
The next option is Margalef’s Richness Index, which takes the total sample size, as well as the number of species observed, into account. This is another measure of richness but is more appropriate for an audience that is familiar with the ln button on their calculator.
The rest of the options utilize Simpson's Diversity Index. There are two SDI options for each simulation (Biodiversity and Macroinvertebrates). There are two slightly different versions of the SDI formula. One is the version that appears on the AP Biology formula sheet. The other is the more common version of the formula. Both require more calculation work than species richness, so these options are better suited for students who are ready for that. The math is not particularly difficult but requires some organization and the use of n and N as separate variables can confuse some students who aren't used to working with these types of formulas. For more on how to use the formulas, and a brief explanation of the differences between the two versions of the formulas, see this post.