Question 1

How do gaps affect climax communities? Does gap size matter, and why or why not?

Accepted Answer

The answer of How do gaps affect climax communities? Does...

Question 2

(Figure 19.14) This figure shows the importance of different tree species in the canopy and understorey of a forest. Why did the researchers who conducted this study suggest that the future canopy will have fewer oaks and hickories?

Accepted Answer

The answer of  
(Figure 19.14) This figure shows the...

Question 3

Electrical companies have discovered that dense shrub thickets, once established, can prevent growth of trees under power lines. Which mechanism of succession are these companies using by planting shrubs under power lines?

Accepted Answer

A)  facilitation 
B)  inhibition 
C)  tolerance 
D)  shade tolerance

Question 4

You observe three beech-maple forests in Indiana that began as ponds. How might you determine whether they all started succession with the same community composition?

Accepted Answer

A)  carbon-date the maple and beech trees to see how long they have been living; older trees would suggest a more diverse starting community 
B)  calculate the species diversity of lichens found on the trees 
C)  try growing different types of pioneer species at each site 
D)  sample the soils at each site for pollen and carbon-date them to get an estimate of the species that appeared first at the site

Question 5

When succession was initially observed on the islands of Krakatau, plants with _____ seeds dominated.

Accepted Answer

A)  animal-dispersed 
B)  wind-dispersed 
C)  sea-dispersed 
D)  ballistic-dispersed

Question 6

Late-succession species are likely to have

Accepted Answer

A)  wind-dispersed seeds. 
B)  large seeds. 
C)  many seeds. 
D)  fast growth rate.

Question 7

What characteristic shared by diatoms and cyanobacteria might make them good colonizers of nutrient-poor habitats?

Accepted Answer

A)  They are both extremely tough to eat. 
B)  They are both unicellular. 
C)  They both photosynthesize light to make carbohydrates. 
D)  They both have adaptations that allow them to survive droughts.

Question 8

In primary succession of sand dunes, the first species to colonize are

Accepted Answer

A)  lichens. 
B)  grasses. 
C)  herbs. 
D)  mosses.

Question 9

Which mechanisms of succession depend on one species arriving at a site before another species?

Accepted Answer

A)  inhibition and tolerance 
B)  facilitation and inhibition 
C)  tolerance and facilitation 
D)  inhibition, facilitation, and tolerance

Question 10

A climax community is generally composed of organisms

Accepted Answer

A)  that dominate in a given biome. 
B)  that were present throughout succession. 
C)  from surrounding communities. 
D)  that are common.

Question 11

Topic succession in terrestrial environments
Level: medium
The assumptions behind the valid use of chronosequences are usually not all met. How, then, do researchers establish the most likely scenario of terrestrial succession in a given area?

Accepted Answer

The answer of Topic succession in terrestrial environments
Level: medium
The assumptions...

Question 12

Invasion of cheatgrass (Bromus tectorum) in the western North America is maintained by

Accepted Answer

A)  occasional hurricanes. 
B)  periodic fires. 
C)  extensive grazing. 
D)  frequent logging.

Question 13

(Figure 9.12) In the experiment associated with the figure, acorn barnacles facilitate the growth of algae. If you removed both acorn barnacles and the limpet predators of algae, what would you be likely to observe over time?

Accepted Answer

A)  a dense carpet of little brown barnacles only 
B)  a carpet of little brown barnacles followed by algal growth 
C)  no colonization of any organisms 
D)  a dense carpet of algae only

Question 14

Why is tolerance a mechanism that can be found in both early and late seral stages?

Accepted Answer

A)  Both early and late seral species need to be tolerant to low levels of moisture. 
B)  Both early and late seral species require high temperatures to germinate. 
C)  Early seral species need tolerance of stressful environments, while late seral species need tolerance of deep shade. 
D)  Early seral species are tolerant to insects and late seral species are tolerant to fire.

Question 15

A mechanism of succession in which the presence of one species increases the probability that a second species can become established is

Accepted Answer

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

Question 16

Succession in intertidal communities is rapid because

Accepted Answer

A)  the climax community has only a small number of species. 
B)  the generation time of the dominant species is shorter. 
C)  species easily disperse into the disturbed habitat. 
D)  algae have a very rapid growth rate.

Question 17

Topic: creating gaps in a climax community
How are floods that remove organic matter on the surface of rocks similar to gaps observed in forests?

Accepted Answer

A)  Both scour the landscape clean. 
B)  Both uncover seeds in the soil. 
C)  Both allow early-succession species to colonize. 
D)  Both happen only in climax seral stages.

Question 18

What role does disturbance play in the recently discovered mechanism of pond succession that isn't found in the classical mechanism of succession?

Accepted Answer

A)  Droughts lower water levels so that plants can colonize lake sediments. 
B)  Rushing water scours the bottom of the lakes, allowing diatoms to colonize. 
C)  Glaciers scour the land, leaving depressions that can fill up with melting water. 
D)  Peat fires remove the vegetation, allowing secondary succession to proceed.

Question 19

Terrestrial primary succession begins with

Accepted Answer

A)  lichens and mosses. 
B)  grasses and herbs. 
C)  lichens and grasses. 
D)  mosses and grasses.

Question 20

Indirect observations of succession are often done by using

Accepted Answer

A)  chronosequences and seral stages. 
B)  seral stages and climax communities. 
C)  climax communities and pollen. 
D)  chronosequences and pollen.

Exam 19: Community Succession