Question 1

(Figure 19.14) Researchers studying deciduous forests in the U.S. state of Pennsylvania found that browsing by deer in mature climax forests caused changes in the understorey. The figure shows the importance values for the trees in the canopy and the understorey. What do these results suggest about the stability of the current climax community?

Accepted Answer

Because extensive deer browsing has been...

Question 2

Which of the following habitats could NOT undergo secondary succession?

Accepted Answer

A)   mud slide
B)   bare rock
C)   clear-cut forest
D)   severely burned forest

Question 3

In the study of stream succession following a major flood event at Sycamore Creek in Arizona, what was the first organism to recolonize the stream?

Accepted Answer

A)   fish
B)   Cladophora
C)   cyanobacteria
D)   diatoms

Question 4

To apply the concept of chronosequence, ecologists assume that:

Accepted Answer

A)   most terrestrial communities go through the same seral stages.
B)   the layers in pond sediments are stacked from youngest at the top to the oldest at the bottom.
C)   older sites and younger sites have undergone the same disturbances.
D)   wider tree rings represent periods of rapid population growth.

Question 5

Researchers have recently proposed a new way lake succession can occur. What is one feature of this new model?

Accepted Answer

A)   Lake succession is slow and steady.
B)   Colonization of plants happens from the lakeshore.
C)   Colonization of plants happens from the sediments at the lake bottom.
D)   The production of a peat layer is not necessary in lake succession.

Question 6

What is the clearest way to document succession?

Accepted Answer

A)   pollen sediments from a pond
B)   direct observation
C)   tree rings
D)   carbon dating of wood

Question 7

In deciduous forests of Pennsylvania in the United States, the climax community used to be composed of large trees of mostly oak, hickory, and tulip poplar, but over time the composition of the understorey changed to sugar maple and beech. What was the cause of this shift?

Accepted Answer

A)   The original species were infected by a pathogen.
B)   Sugar maple and beech were facilitated by the original species.
C)   Deer browsing caused reductions in species that were not browse tolerant.
D)   The seedlings of the original species were not shade tolerant.

Question 8

Topic: Climax communities under extreme environmental conditions
In some areas of the western United States pines are an important part of the climax community. Fires occur at regular intervals in these areas. How could fire maintain these pine populations?

Accepted Answer

A)   Fires allow pioneer species like annual grasses to colonize.
B)   Fires cause gaps in the canopy that allow early-succession species to thrive.
C)   Fires kill understorey species, allowing pine seedlings to thrive.
D)   Fires make it easier for legumes to colonize, increasing soil nitrogen.

Question 9

Which of the following is a pioneer species?

Accepted Answer

A)   annual plants with small, light seeds
B)   plants with large, heavy seeds
C)   animals that stay affixed to a substrate, like sea anemones
D)   animals that tend to stay very close to where they were born

Question 10

In fire-maintained climax communities in the southeastern United States, periodic fires

Accepted Answer

A)   change soil conditions so they do not favour oaks or broadleaf species.
B)   cause rapid compensatory growth of burned pines.
C)   kill oak and other broadleaf species but not pines.
D)   change water relations to conditions that favour pines.

Question 11

Why does succession in intertidal communities tend to happen faster than succession after a disturbance in terrestrial communities?

Accepted Answer

A)   The ocean has a higher concentration of organisms than soil.
B)   There are many more disturbances in the intertidal zones than in terrestrial areas.
C)   The generation time of dominant species in the intertidal zone is shorter than that of the dominant species in terrestrial habitats.
D)   The generation time of dominant species in terrestrial habitats is shorter than that of the dominant species in the intertidal zone.

Question 12

The last seral stage in the process of succession is called the _____ community.

Accepted Answer

A)   apex
B)   baseline
C)   climax
D)   final

Question 13

Why does stream succession rely less on how fast organisms can move themselves than terrestrial succession?

Accepted Answer

A)   Most streams are short.
B)   Water can carry organisms from less disturbed to more disturbed sites.
C)   Most stream organisms are algae.
D)   Succession happens very slowly in streams.

Question 14

Secondary succession takes place in habitats that

Accepted Answer

A)   are initially devoid of plants and organic soil.
B)   have some plants following disturbance.
C)   have some plants following disturbance but do not have organic soil.
D)   have been disturbed and contain no plants but still contain organic soil.

Question 15

Why don't gaps in a forest canopy always help early-succession species establish?

Accepted Answer

If the gap is small enough, ne...

Question 16

Early-succession plant species are often shade intolerant, whereas late-succession plant species are often shade tolerant. Why are differences in shade tolerance important in succession?

Accepted Answer

Early in succession, there is often litt...

Question 17

(Figure 19.10)  These graphs show that succession is associated with a rapid increase in species richness that slows and levels off over time. How might you explain a graph showing succession with an initial increase in species richness followed by a decline in species richness over time?

Accepted Answer

A)   a disturbance such as fire
B)   facilitation
C)   inhibition
D)   tolerance

Question 18

Why does secondary succession occur faster than primary succession?

Accepted Answer

A)   Direct observation of secondary succession is easier than for primary succession.
B)   Lichens are better able to colonize soil than bare rock.
C)   Soil in secondary sites can contain plant seeds and roots.
D)   Primary succession areas get too much sunlight for succession to happen quickly.

Question 19

Inhibition is a mechanism of succession in which

Accepted Answer

A)   the probability that a species can become established depends on the presence of another species.
B)   the arrival of one species at a site affects the subsequent colonization of other species.
C)   one species decreases the probability that a second species will become established.
D)   one species increases the probability that a second species will become established.

Question 20

Some of the first species to colonize an area following disturbance have to persevere under inhospitable conditions such as disturbed soils, low soil moisture, and altered nutrient levels. This is an example of

Accepted Answer

A)   the priority effect.
B)   facilitation.
C)   inhibition.
D)   tolerance.

Exam 19: Community Succession

Why does secondary succession occur faster than primary succession?

Correct Answer
verified

Early-succession plant species are often shade intolerant, whereas late-succession plant species are often shade tolerant. Why are differences in shade tolerance important in succession?

Correct Answer
verified
Early in succession, there is often litt...
View Answer

In deciduous forests of Pennsylvania in the United States, the climax community used to be composed of large trees of mostly oak, hickory, and tulip poplar, but over time the composition of the understorey changed to sugar maple and beech. What was the cause of this shift?

Correct Answer
verified

(Figure 19.10) These graphs show that succession is associated with a rapid increase in species richness that slows and levels off over time. How might you explain a graph showing succession with an initial increase in species richness followed by a decline in species richness over time?

Correct Answer
verified

In the study of stream succession following a major flood event at Sycamore Creek in Arizona, what was the first organism to recolonize the stream?

Correct Answer
verified

Some of the first species to colonize an area following disturbance have to persevere under inhospitable conditions such as disturbed soils, low soil moisture, and altered nutrient levels. This is an example of

Correct Answer
verified

Why does stream succession rely less on how fast organisms can move themselves than terrestrial succession?

Correct Answer
verified

Inhibition is a mechanism of succession in which

Correct Answer
verified

The last seral stage in the process of succession is called the _____ community.

Correct Answer
verified

Secondary succession takes place in habitats that

Correct Answer
verified

Why does succession in intertidal communities tend to happen faster than succession after a disturbance in terrestrial communities?

Correct Answer
verified

Correct Answer
verified
Because extensive deer browsing has been...
View Answer

Researchers have recently proposed a new way lake succession can occur. What is one feature of this new model?

Correct Answer
verified

Why don't gaps in a forest canopy always help early-succession species establish?

Correct Answer
verified
If the gap is small enough, ne...
View Answer

Which of the following habitats could NOT undergo secondary succession?

Correct Answer
verified

Which of the following is a pioneer species?

Correct Answer
verified

Topic: Climax communities under extreme environmental conditions In some areas of the western United States pines are an important part of the climax community. Fires occur at regular intervals in these areas. How could fire maintain these pine populations?

Correct Answer
verified

To apply the concept of chronosequence, ecologists assume that:

Correct Answer
verified

What is the clearest way to document succession?

Correct Answer
verified

In fire-maintained climax communities in the southeastern United States, periodic fires

Correct Answer
verified

Exam 19: Community Succession

Why does secondary succession occur faster than primary succession?

Correct AnswerverifiedShow Answer

Early-succession plant species are often shade intolerant, whereas late-succession plant species are often shade tolerant. Why are differences in shade tolerance important in succession?

Correct AnswerverifiedEarly in succession, there is often litt...View AnswerShow Answer

In deciduous forests of Pennsylvania in the United States, the climax community used to be composed of large trees of mostly oak, hickory, and tulip poplar, but over time the composition of the understorey changed to sugar maple and beech. What was the cause of this shift?

Correct AnswerverifiedShow Answer

(Figure 19.10) These graphs show that succession is associated with a rapid increase in species richness that slows and levels off over time. How might you explain a graph showing succession with an initial increase in species richness followed by a decline in species richness over time?

Correct AnswerverifiedShow Answer

In the study of stream succession following a major flood event at Sycamore Creek in Arizona, what was the first organism to recolonize the stream?

Correct AnswerverifiedShow Answer

Some of the first species to colonize an area following disturbance have to persevere under inhospitable conditions such as disturbed soils, low soil moisture, and altered nutrient levels. This is an example of

Correct AnswerverifiedShow Answer

Why does stream succession rely less on how fast organisms can move themselves than terrestrial succession?

Correct AnswerverifiedShow Answer

Inhibition is a mechanism of succession in which

Correct AnswerverifiedShow Answer

The last seral stage in the process of succession is called the _____ community.

Correct AnswerverifiedShow Answer

Secondary succession takes place in habitats that

Correct AnswerverifiedShow Answer

Why does succession in intertidal communities tend to happen faster than succession after a disturbance in terrestrial communities?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedBecause extensive deer browsing has been...View AnswerShow Answer

Researchers have recently proposed a new way lake succession can occur. What is one feature of this new model?

Correct AnswerverifiedShow Answer

Why don't gaps in a forest canopy always help early-succession species establish?

Correct AnswerverifiedIf the gap is small enough, ne...View AnswerShow Answer

Which of the following habitats could NOT undergo secondary succession?

Correct AnswerverifiedShow Answer

Which of the following is a pioneer species?

Correct AnswerverifiedShow Answer

Topic: Climax communities under extreme environmental conditions In some areas of the western United States pines are an important part of the climax community. Fires occur at regular intervals in these areas. How could fire maintain these pine populations?

Correct AnswerverifiedShow Answer

To apply the concept of chronosequence, ecologists assume that:

Correct AnswerverifiedShow Answer

What is the clearest way to document succession?

Correct AnswerverifiedShow Answer

In fire-maintained climax communities in the southeastern United States, periodic fires

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
Early in succession, there is often litt...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Because extensive deer browsing has been...
View Answer

Correct Answer
verified

Correct Answer
verified
If the gap is small enough, ne...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified