Laboratory 2: Calculation of Species Diversity Indices
Description
In this interactive lab, students move from raw species-count data to a full quantitative picture of biodiversity. Working through a guided, step-by-step calculator, students compute relative abundance and then build up the Shannon-Wiener diversity index, Simpson's diversity index, and Pielou's evenness index by hand, first for a worked two-site example and then independently for a second site, watching how sites with identical species richness can still differ sharply in diversity and evenness. Students then apply the full workflow to a three-habitat comparison, ranging from natural vegetation to an urban disturbed area, calculating and ranking all three habitats by biodiversity, visualizing their results with rank-abundance curves, and interpreting what the numbers reveal about ecological health and disturbance.
Learning Outcomes
By the end of this lab, students will be able to distinguish species richness, diversity, and evenness as related but distinct concepts, and calculate the abundance and relative abundance of species from raw count data. Students will also be able to calculate and interpret the Shannon-Wiener diversity index, Simpson's diversity index, and Pielou's evenness index, and explain what higher or lower values of each indicate ecologically. Finally, students will be able to compare biodiversity across multiple ecological communities using these indices together, rank habitats by biodiversity, and explain how relative abundance and dominance, not just species count, shape our understanding of ecosystem health.