2. Biodiversity

Measuring Biodiversity — Quiz

Test your understanding of measuring biodiversity with 5 practice questions.

Practice Questions

Question 1

The Shannon diversity index ($H$) is calculated using the formula $H = -\sum_{i=1}^{S} (p_i \ln p_i)$, where $p_i$ is the proportion of individuals belonging to species $i$ and $S$ is the total number of species. If a community has a very low Shannon diversity index, what does this primarily suggest about its structure?

Question 2

When conducting a biodiversity survey in a highly fragmented landscape, such as an agricultural area interspersed with small forest patches, which sampling strategy would be most effective for accurately assessing the overall biodiversity across the entire landscape?

Question 3

The effective number of species, often derived from diversity indices like the Shannon index ($e^H$) or the inverse Simpson index ($1/D$), provides a more intuitive measure of diversity than the raw index values. If two communities, Community X and Community Y, both have a species richness of 10, but Community X has an effective number of species of 7.5 and Community Y has an effective number of species of 4.2, what is the most significant ecological difference between them?

Question 4

A long-term ecological study is monitoring the biodiversity of a freshwater lake ecosystem. Over a decade, researchers observe a significant decline in the Shannon diversity index ($H$) and an increase in the dominance of a few algal species. What is the most probable long-term ecological consequence for this lake ecosystem?

Question 5

Consider a biodiversity survey where the species-area curve is being constructed. The curve shows a steep initial increase in species count with increasing area, but then the slope gradually flattens out. What does the flattening of the species-area curve primarily indicate?