Q: Which equation best represents the calculation of species diversity in a community?

$$\text{Species diversity} = \text{Species richness} + \text{Species abundance}$$

Question 1

Which of the following best describes the difference between species richness and species abundance in a community?

Accepted Answer

Species richness refers to the number of different species present, while species abundance refers to the proportional representation of each species.

Question 2

A grassland plot contains 4 species, each making up 25% of the total individuals. Another plot contains 4 species, but one species makes up 80% of the individuals and the others are much less common. Which plot is more diverse and why?

Accepted Answer

The first plot is more diverse because both species richness and species abundance are more evenly distributed.

Question 3

Why are food chains typically limited to only a few trophic levels?

Accepted Answer

Because energy is lost at each trophic level, limiting the amount available to higher levels.

Question 4

Which of the following is an example of a keystone species and why?

Accepted Answer

Sea otters, because their predation on sea urchins maintains kelp forest ecosystems.

Question 5

A beaver builds a dam, creating a pond and changing the local environment. What ecological role does the beaver play?

Accepted Answer

Foundation species/ecosystem engineer

Question 6

After a forest fire, grasses and perennials are the first to grow back, followed by shrubs and trees. What type of ecological process is this?

Accepted Answer

Secondary succession

Question 7

Which equation best represents the calculation of species diversity in a community?

Accepted Answer

$$	ext{Species diversity} = 	ext{Species richness} + 	ext{Species abundance}$$

Question 8

In the experiment at Cedar Creek Natural History Area, why did plots with more plant species tend to be healthier and more productive?

Accepted Answer

Higher diversity increases ecosystem stability and resource use efficiency.

Question 9

Which of the following best describes the role of decomposers in a food web?

Accepted Answer

They recycle nutrients by breaking down dead organisms, supporting primary producers.

Question 10

A disturbance removes all vegetation and soil from an area, such as after a volcanic eruption. What is the first stage of recovery called?

Accepted Answer

Primary succession

Question 11

Which of the following is a likely consequence of removing a keystone predator from a community?

Accepted Answer

A decrease in species diversity due to unchecked population growth of prey species.

Question 12

Which of the following scenarios best illustrates the concept of an invasive species?

Accepted Answer

Purple loosestrife spreading rapidly in BC waterways, outcompeting native plants.

Question 13

If a community is disturbed by a flood but the soil remains intact, what type of succession will most likely occur?

Accepted Answer

Secondary succession

Question 14

Which of the following best explains why dominant species are often the most abundant in a community?

Accepted Answer

They outcompete other species for resources and are successful at avoiding predation and disease.

Question 15

A food web is considered more realistic than a food chain because:

Accepted Answer

It shows the complex feeding relationships and multiple connections among species.

Question 16

Which of the following is NOT a likely effect of introducing an invasive species into a new community?

Accepted Answer

Immediate increase in native species diversity.

Question 17

During ecological succession at Glacier Bay, Alaska, which stage is associated with the highest increase in soil nitrogen content?

Accepted Answer

Alder stage

Question 18

Which of the following best describes the non-equilibrium model of community structure?

Accepted Answer

Communities are constantly changing, especially after disturbances.

Question 19

Which of the following equations best represents the energy transfer between trophic levels in a food chain?

Accepted Answer

$$E_n = E_{n-1} 	imes 0.1$$

Community Ecology II: Diversity, Trophic Structure, Succession, and Invasive Species

Study Guide - Practice Questions

Study Guide - Flashcards