Question 1

Which of the following is most likely the main advantage of controlled burnings of forested areas?

Accepted Answer

Controlled burnings prevent the overgrowth of the underbrush, which can lead to potential wildfires. By clearing out the underbrush, it allows for new growth and healthier forest ecosystems. The other options (A, B, and D) do not accurately represent the main advantage of controlled burnings.

Question 2

Which are the only two interaction types to depend on density and effective defense to determine the short-term impact?

Accepted Answer

Consumption and parasitism are the only two interaction types where the short-term impact depends on density and effective defense. In consumption, the population density of the prey determines the amount of food available for the predator, and the effectiveness of the prey's defenses determines its survival. In parasitism, the population density of the host determines the number of hosts available for the parasite, and the effectiveness of the host's defenses determines its susceptibility to parasitism. In contrast, competition, mutualism, and commensalism do not depend on density and effective defense to determine their short-term impact.

Question 3

Figure 53.11 
-According to Figure 53.11,a species has the highest chance of extinction when

Accepted Answer

The answer of Figure 53.11 
-According to Figure 53.11,a species...

Question 4

A measure of how much a community is affected by a disturbance is termed

Accepted Answer

Resistance refers to the ability of a community to remain unchanged when subjected to a disturbance.

Question 5

During succession,tall canopies of maple trees form allowing chipmunks to be better hidden against hawks.This is an example of

Accepted Answer

This is an example of facilitation because the tall canopies of maple trees provide a better habitat for chipmunks, allowing them to be more easily hidden from predators. This supports the growth and survival of the chipmunk population, which is a positive effect on the overall ecosystem.

Question 6

Which one of the following animals would most likely be defined as a keystone species?

Accepted Answer

A keystone species is one that plays a critical role in maintaining the structure and function of an ecosystem. Sea otters are considered a keystone species because their presence regulates populations of sea urchins, which in turn prevents overgrazing of kelp forests. Kelp forests provide habitat for a variety of other species and help to sequester carbon dioxide from the atmosphere. Without sea otters, the entire ecosystem could be drastically altered. The other options (housefly, fathead minnow, nauplii) do not fit the criteria for a keystone species.

Question 7

Bouchard and Brooks (2004)studied the effect of insect flight on dispersal and speciation in rain-forest insects.They sampled all of the insects in the study area and found that 60 insect species are flightless and 19 are macropterous (able to fly).After analyzing the results of the Bouchard and Brooks study,you conclude that macropterous and flightless insects in the rain forests of northeastern Australia have dispersed and speciated in similar manners.What does this say about flight in these insects?

Accepted Answer

The fact that macropterous and flightless insects have dispersed and speciated in similar manners suggests that flight is not increasing dispersal efficiency in this community.

Question 8

Bouchard and Brooks (2004)studied the effect of insect flight on dispersal and speciation in rain-forest insects.They sampled all of the insects in the study area and found that 60 insect species are flightless and 19 are macropterous (able to fly).From this information what can you conclude? (P.Bouchard and D.R.Brooks.2004.Effect of vagility potential on dispersal and speciation in rainforest insects.Journal of Evolutionary Biology 17:994-1006.)

Accepted Answer

The answer of Bouchard and Brooks (2004)studied the effect of...

Question 9

Which of the following is not an example of a mutualism?

Accepted Answer

This is an example of commensalism, where one species benefits (bird) and the other is unaffected (army ants). In mutualism, both species benefit from the interaction.

Question 10

Figure 53.7 
-What does the graph in the figure above tell you about the definition of a keystone species?

Accepted Answer

The graph shows that removing the keystone species (represented by the black bar) has a large impact on the species richness (number of different species) in the community, indicating that keystone species have a significant role in maintaining ecosystem stability.

Question 11

Clements's view of biological communities is that of a highly predictable and interrelated structure,while Gleason's view of biological communities is that individual species operate independently.If we set up many identical sterilized ponds in the same area and allowed them to be colonized,what should we predict if Gleason's hypothesis is the one we believe is correct?

Accepted Answer

According to Gleason's view, individual species operate independently and therefore, different communities are likely to develop in each pond due to chance events in colonization and species interactions. The variability in community composition could also be influenced by abiotic factors such as light, temperature, and nutrient availability. Therefore, option C is the best choice.

Question 12

Figure 53.8 
-Clements's view of biological communities is that of a highly predictable and interrelated structure,while Gleason's view of biological communities is that individual species operate independently.Looking at the results in the figure above,which hypothesis (by Clements or Gleason)is supported by the data?

Accepted Answer

The answer of Figure 53.8 
-Clements's view of biological communities...

Question 13

Figure 53.10 
-In figure above,what can be stated about species diversity and latitude?

Accepted Answer

The graph shows a clear trend of decreasing species diversity as latitude increases. This is supported by the decreasing number of species in the top right corner of the graph compared to the bottom left corner.

Question 14

Figure 53.9 
-In the figure above,which community has the highest species diversity?

Accepted Answer

Community 2 has the highest species diversity because it has the highest number of species (10) and a more even distribution of individuals among those species, as indicated by the Shannon index value of 2.3. In contrast, while community 3 also has 10 species, there is a dominance of one species (58% of individuals), resulting in a lower Shannon index value of 1.5.

Question 15

Figure 53.9 
-In the figure above,which community has the highest species richness?

Accepted Answer

Community 2 has the highest species richness because it has the most vertical lines (indicating different species) within each box. Community 1 has the lowest species richness as it has the fewest number of vertical lines in each box. Community 3 and 4 have similar species richness but still less than community 2.

Question 16

During a one year study,researchers found no difference in treehopper populations in any of their control and experimental groups.What could they measure during the second year to gain information about why this might have occurred?

Accepted Answer

Since there was no difference in treehopper populations in the control and experimental groups, it is possible that predation or competition could be affecting the populations. Therefore, measuring the relative abundance of jumping spiders (a common predator of treehoppers) could provide insight into why there was no difference observed in the first year.

Question 17

Figure 53.11 
-Which of the following statements regarding the figure above is true?

Accepted Answer

The figure shows a positive correlation between island size and species richness, and also suggests that islands closer to the mainland have higher species richness. Therefore, C is the correct answer. A and D are incorrect because the figure does not provide any information on immigration rates or species diversity on larger islands away from the mainland. B is incorrect because the figure does not provide any direct information on extinction rates.

Question 18

What is the main difference between a disturbance and a disturbance regime?

Accepted Answer

A disturbance is a temporary change in environmental conditions that disrupts the normal functioning of an ecosystem. On the other hand, a disturbance regime refers to the predictable frequency and severity of disturbances that occur in an ecosystem over time. Therefore, option A is the correct answer as it clearly defines the main difference between a disturbance and a disturbance regime.

Question 19

Figure 53.6 
-Treehoppers (a type of insect)produce honeydew,which ants use for food.Treehoppers have a major predator,the jumping spider.Researchers hypothesized that the ants would protect the treehoppers from the spiders.In an experiment,researchers followed study plots with ants removed from the system and compared them to a control plot.In the figure above,what can you conclude?

Accepted Answer

The figure shows that in the control plot (with ants present), the number of spiders caught is significantly higher than in the plot with ants removed. This suggests that ants may be playing a role in protecting the treehoppers from their major predator, the jumping spider. Therefore, the best conclusion is that ants do somehow protect the treehoppers from spiders.

Quiz 53: Community Ecology

Which of the following is most likely the main advantage of controlled burnings of forested areas?

Which are the only two interaction types to depend on density and effective defense to determine the short-term impact?

Figure 53.11 -According to Figure 53.11,a species has the highest chance of extinction when

A measure of how much a community is affected by a disturbance is termed

During succession,tall canopies of maple trees form allowing chipmunks to be better hidden against hawks.This is an example of

Which one of the following animals would most likely be defined as a keystone species?

Which of the following is not an example of a mutualism?

Figure 53.7 -What does the graph in the figure above tell you about the definition of a keystone species?

Figure 53.10 -In figure above,what can be stated about species diversity and latitude?

Figure 53.9 -In the figure above,which community has the highest species diversity?

Figure 53.9 -In the figure above,which community has the highest species richness?

During a one year study,researchers found no difference in treehopper populations in any of their control and experimental groups.What could they measure during the second year to gain information about why this might have occurred?

Figure 53.11 -Which of the following statements regarding the figure above is true?

What is the main difference between a disturbance and a disturbance regime?