Question 1

Which of the following best describes 'biodiversity' as used in ecology?

Accepted Answer

The variety of important ecological entities across multiple spatial scales, including genes, species, and communities.

Question 2

Why is standardized sampling important when estimating species diversity in different locations?

Accepted Answer

It allows for the comparison of relative abundance and diversity between sites by using the same plot sizes and methods.

Question 3

Which of the following is NOT a component of community diversity?

Accepted Answer

Population density

Question 4

A researcher samples a forest and finds 5 species with the following proportions: 0.6, 0.133, 0.133, 0.067, 0.067. What is the species richness ($$S) of $$this community?

Accepted Answer

$$S = 5$$

Question 5

Which formula is used to calculate the Shannon Index ($$H') $$for species diversity?

Accepted Answer

$$H' = -\sum_{i=1}^{s} p_i \ln p_i$$

Question 6

If Community A has a Shannon Index ($$H') of 1.21 $$and Community B has $$H' of 1.61$$, what can you infer?

Accepted Answer

Community B has greater species diversity than Community A.

Question 7

Which hypothesis predicts a linear increase in community function as species richness increases?

Accepted Answer

Complementarity hypothesis

Question 8

A scientist is sampling a community and notices that the number of new species found plateaus as more individuals are sampled. What does this indicate?

Accepted Answer

Most species in the community have likely been detected.

Question 9

Which of the following best describes 'species evenness'?

Accepted Answer

The relative abundance of each species in a community.

Question 10

Why do tropical regions generally have higher species richness than temperate regions?

Accepted Answer

Tropical regions have more stable climates and greater environmental complexity, supporting more niches.

Question 11

Which of the following is a consequence of higher biodiversity in a community?

Accepted Answer

Increased stability and ability to perform more ecosystem functions.

Question 12

A community has 4 species with the following proportions: 0.4, 0.3, 0.2, 0.1. Calculate the Shannon Index ($$H') $$for this community. (Use $$\ln$$ for natural log.)

Accepted Answer

$$H' = -[0.4 \ln 0.4 + 0.3 \ln 0.3 + 0.2 \ln 0.2 + 0.1 \ln 0.1]$$

Question 13

Which of the following is an example of an 'indicator taxon' used in biodiversity studies?

Accepted Answer

A group of species that is easy to find and reflects the diversity of the larger community.

Question 14

Which of the following best explains why environmental complexity increases species diversity?

Accepted Answer

It increases the number of available niches, allowing more species to coexist.

Question 15

Which hypothesis suggests that the effect of species richness on community function eventually reaches an upper limit?

Accepted Answer

Redundancy hypothesis

Question 16

A rank-abundance curve for two communities shows that Community X has a longer, less steep line than Community Y. What does this indicate about Community X?

Accepted Answer

Community X has higher species richness and evenness.

Question 17

Which of the following is NOT a function typically enhanced by greater biodiversity in a community?

Accepted Answer

Increased susceptibility to invasive species

Question 18

Which of the following best describes the 'driver and passenger' hypothesis in the context of biodiversity and ecosystem function?

Accepted Answer

Some species have a much stronger effect on ecosystem function than others.

Question 19

Why do scientists use diversity indices like the Shannon Index to compare communities?

Accepted Answer

They provide a single value that combines richness and evenness, allowing for easier comparison.

Question 20

Which of the following is a practical step in preserving biodiversity, as previewed in conservation biology?

Accepted Answer

Protecting habitats and maintaining ecosystem functions.

8.1 Species Abundance, Diversity, and Biodiversity in Ecological Communities

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