Question 1

According to the _______ model of succession, the early successional species modify the environment so as to facilitate the subsequent colonization of other early colonizing species.

Accepted Answer

The answer of According to the _______ model of succession,...

Question 2

Refer to the figure.
 In their work on aspen-fir interactions, Calder and St. Clair claim that aspens are facilitated by the presence of fir trees. From these data, what is the primary evidence for aspen being facilitated by fir?

Accepted Answer

The answer of Refer to the figure.
 In their work...

Question 3

Suppose that a late succession plant that is surrounded by early succession plants grows at a rate of 0.5 cm per day. If the early succession plants are removed experimentally, the late succession plants are observed to grow at a rate of 0.9 cm per day. This experiment shows that the early succession plants have a _______ effect on the late succession plants, and this observation is most consistent with the _______ model of succession.

Accepted Answer

The early succession plants have a negative effect on the late succession plants because their removal leads to increased growth of the late succession plants. This observation is consistent with the inhibition model of succession, where early species inhibit the growth of later species.

Question 4

In his studies of succession in Glacier Bay, Chapin found that as communities went from early to latter stages of succession, soil moisture _______ and nitrogen _______.

Accepted Answer

As succession progresses, soil moisture and nitrogen levels typically increase due to the accumulation of organic matter and the development of more complex plant communities that enhance soil properties.

Question 5

In their studies of succession in Glacier Bay, Alaska, Chapin and colleagues found that the survival rate of germinated spruce seeds was highest at the _______ stage.

Accepted Answer

The pioneer stage is the first stage of succession, and it is characterized by the establishment of fast-growing, opportunistic species that can tolerate harsh conditions. In Glacier Bay, Alaska, Chapin and colleagues found that the survival rate of germinated spruce seeds was highest at the pioneer stage. This is likely because the pioneer species create a more favorable environment for the growth of spruce seedlings by providing shade and protection from the elements.

Question 6

The studies by Chapin and colleagues on Glacier Bay succession provide empirical support for which model(s) of succession?

Accepted Answer

Chapin and colleagues' studies on Glacier Bay succession demonstrated that all three models—facilitation, tolerance, and inhibition—play roles at different stages of the ecological succession process.

Question 7

Refer to the figure.
 Chapin et al. conducted their work in Glacier Bay in 1994. If we were to return today to his plots, what could we predict to find in his former ten year-old pioneer communities that had been dominated by low shrubs, herbs, mosses, liverworts, and lichens?

Accepted Answer

The answer of Refer to the figure.
 Chapin et al....

Question 8

At which stage of succession is facilitation usually the most significant factor?

Accepted Answer

Facilitation is most significant in the early stages of succession, where pioneer species modify the environment, making it more suitable for subsequent species.

Question 9

Refer to the figure.
 In Farrell's (1991) work on algal succession, the presence of limpets had what effect on the growth of algae?

Accepted Answer

The answer of Refer to the figure.
 In Farrell's (1991)...

Question 10

Which statement about succession in the glaciers of Alaska is false?

Accepted Answer

The earliest stage of succession in the glaciers of Alaska is typically dominated by pioneer species like mosses and lichens, not alders. Alders appear in later stages of succession.

Question 11

You are in Glacier Bay. Starting at a location dominated by alders, you would most likely first run into the _______ stage if you travelled toward the glacier's edge and the _______ stage if you travelled away from the glacier's edge.

Accepted Answer

As you travel toward the glacier's edge, you encounter the Dryas stage, which follows the alder stage in succession. Moving away from the glacier, you would encounter the spruce stage, which comes later in the succession process.

Question 12

Which manipulation(s) did Bertness and Shumway perform in their studies of succession in a New England salt marsh?

Accepted Answer

Bertness and Shumway's studies involved selectively removing particular plant species to understand their role in succession within the salt marsh ecosystem.

Question 13

In their manipulative studies of succession in a New England salt marsh, Bertness and Shumway altered salt stress in certain fields by

Accepted Answer

The answer of In their manipulative studies of succession in...

Question 14

Bertness and Shumway's studies of high salt stress conditions in the middle intertidal regions of New England salt marshes led to which conclusion?

Accepted Answer

Bertness and Shumway found that Distichlis facilitated the colonization of Juncus by ameliorating the high salt stress conditions in the middle intertidal regions.

Question 15

Sousa's studies of intertidal zones in southern California showed that

Accepted Answer

The answer of Sousa's studies of intertidal zones in southern...

Question 16

Farrell's studies of algal succession on the Oregon coast showed that

Accepted Answer

Farrell's studies indicated that Balanus (barnacles) facilitated the growth of algae by protecting them from limpet herbivory, allowing the algae to establish and grow.

Question 17

Refer to the figure.
 The figure is derived from studies of algal succession in the presence and absence of the barnacle Balanus and limpets. Which condition is represented by the purple line (indicated by the black arrow)?

Accepted Answer

The answer of Refer to the figure.
 The figure is...

Question 18

Alternative stable states most often arise

Accepted Answer

Alternative stable states most often arise when there are strong interactions among species, as these interactions can lead to different community configurations that are stable under certain conditions.

Question 19

Which principle is best supported by the results of Sutherland's studies in which fish predators were excluded from a marine fouling community?

Accepted Answer

Sutherland's studies showed that when fish predators were excluded, the community followed a different successional path, indicating that communities can have alternative stable states depending on the presence or absence of predators.

Question 20

Connell and Sousa criticized Sutherland's experiments on alternative stable states in fouling communities on the grounds that

Accepted Answer

Connell and Sousa argued that fouling communities without predators might not be sustainable in natural conditions, questioning the ecological validity of Sutherland's experiments.

Quiz 17: Change in Communities

According to the _______ model of succession, the early successional species modify the environment so as to facilitate the subsequent colonization of other early colonizing species.

Refer to the figure. In their work on aspen-fir interactions, Calder and St. Clair claim that aspens are facilitated by the presence of fir trees. From these data, what is the primary evidence for aspen being facilitated by fir?

In his studies of succession in Glacier Bay, Chapin found that as communities went from early to latter stages of succession, soil moisture _ and nitrogen _.