Deck 45: Community Ecology

Question 1

Community ecology is best defined as the study of

A)plant distributions in a given region.
B)mutual benefits between organisms at all scales in a region.
C)the relationship between abiotic and biotic factors.
D)how groups of species interact in the same place at the same time
E)global scale influences of major disturbances such as volcanos.

Answer 1

D

Question 2

What is an area of the Earth's surface currently undergoing primary succession?

A)Old orange groves in FloridA.
B)Redwood forests along the northwestern U.S.coast.
C)Volcanoes in Iceland.
D)Shallow seas with low productivity.

Answer 2

C

Question 3

In succession,the ability of one species to make the area more suitable for another species is called

A)tolerance.
B)climax succession.
C)inhibition.
D)facilitation.
E)mutualism.

Answer 3

D

Question 4

What information is used to mathematically calculate species diversity? Select all that apply.
__X__ Number of species in the community.
__X__ Relative abundance of species in the community.
_____ Spatial distribution of species in the community.
_____ Frequency of disturbance in the community.
_____ Stability of the community over time.

Question 5

What is true of the Shannon diversity index? Select all that apply.
__X__ Within a community,Its value increases as the number of species sampled increases.
_____ Its value is independent of species relative abundance.
_____ It does not take into account very rare species.
__X__ Its value increases when individuals are more evenly distributed among species.

Question 6

Which of these types of islands is predicted to have the lowest number of species?

A)small island near mainland
B)large island near mainland
C)large island far from mainland
D)small island far from mainland
E)the island closest to mainland regardless of size

Question 7

What is the general global pattern of species richness?

A)Increasing from east to west across continental land masses.
B)Increasing from polar areas towards the tropics.
C)Increasing from tropical seas into temperate forests.
D)Increasing from the tropics towards polar areas.
E)Increasing from clay soil types into organic soils.

Question 8

What is considered to be the primary method of succession in the marine intertidal zone?

A)facilitation.
B)mutualism.
C)equilibrium.
D)tolerance.
E)inhibition.

Question 9

How are species-area relationships traditionally plotted?

A)on a log-linear plot
B)on a bar graph.
C)on a log-log plot
D)on a linear plot
E)as a function of distance

Question 10

In island biogeography,larger islands support ______ species than smaller islands.

A)more
B)fewer
C)larger
D)more recently evolved
E)more ancient

Question 11

What is the most accurate statement about temporal variation of plant biomass of a community?

A)It increases as species diversity increases.
B)It increases as species richness increases.
C)It decreases as species diversity increases.
D)It decreases as species richness decreases.
E)It does not correlate with species richness or diversity.

Question 12

Extinction rates on islands are predicted,based on island biogeography,to be lowest

A)on small islands.
B)on large islands.
C)near islands.
D)far islands.

Question 13

If you (incorrectly)proposed that tundra,the world's largest land biome,contains high species richness,your proposal would be consistent with the

A)area hypothesis.
B)time hypothesis.
C)productivity hypothesis.
D)diversity-stability hypothesis.

Question 14

The moraines left when glaciers retreat are characterized by

A)year-round ice.
B)low nitrogen content and little organic matter.
C)rich,fertile soil.
D)high levels of nitrogen,phosphate and carbon.
E)dense thickets of alders.

Question 15

No matter what model is used to show community succession,the final stage is always

A)a climax community.
B)a secondary community.
C)a community at equilibrium.
D)a stable community.
E)a distubred community.

Question 16

Based on what you know about various species richness hypotheses,a large,tropical continent would likely have __________ species richness.

A)intermmediate
B)low
C)uneven
D)variable
E)high

Question 17

In MacArthur and Wilson's island biogeography model,species richness is a balance between

A)immigration and extinction.
B)inhibition and facilitation.
C)emigration and speciation.
D)tolerance and inhibition.
E)speciation and extinction.

Question 18

In 1992,mangrove forests along the southern Florida coast and the Florida Keys were severely damaged by Hurricane Andrew.Up to 94% mortality was recorded in some areas,with only a few individuals surviving.Scientists have monitored the region and by 2001,the forest canopy had closed and the main species were rapidly gaining biomass.This is an example of:

A)island biogeography.
B)inhibition.
C)the diversity-stability hypothesis.
D)primary succession.
E)secondary succession.

Question 19

Examine the figure above.In the continental U.S. ,the dark green patches show areas with the highest bird species richness.Why would these areas be so species-rich?

A)Because these areas have the highest temperatures in the continental U.S.
B)Because these areas have mountainous terrain,which creates many habitat types.
C)Because in these areas,mountain tops act like islands,accelerating speciation.
D)Because these areas have low frequencies of extreme weather events and fire.

Question 20

You discover a subterranean river in the outback of Australia and estimate that it is at least 50 million years old.You gather a crew of scientists to perform traditional species sampling of the river as well as modern techniques to calculate microbial diversity.The results indicate that the river is extremely diverse - you even get to name a new species of shrimp after yourself! During one of your many interviews,you are asked to explain the high diversity of the subterranean river.What hypothesis would you most likely cite?

A)The time hypothesis.
B)The area hypothesis.
C)The productivity hypothesis.
D)The diversity-stability hypothesis.

Question 21

Calculate the Shannon diversity index.Round your answers to three decimal places and separate answers with a comma and one space.
$$\begin{array} { c } { \text { Community } } \\\begin{array} { | c | c | c | } \hline \text { Species } & \begin{array} { l } \text { Low } \\\text { mash }\end{array} & \begin{array} { l } \text { Him } \\\text { mars }\end{array} \\\hline 1 & 19 & 7 \\\hline 2 & 26 & 6 \\\hline 3 & 15 & 82 \\\hline 4 &0 & 7 \\\hline 5 & 0 & 3 \\\hline \text { Tatal } & 60 & 95 \\\hline\end{array}\end{array}$$
The Shannon diversity index for the low marsh is __.The Shannon diversity index for the high marsh is __.

Question 22

Community A and Community B both have 54 beetle species,but Community A has more total individuals than Community

A)Community B would have a higher Shannon index value.
B)Community A would have a higher Shannon index value.
B)If you were to calculate the Shannon diversity index for both communities,what would be the result?
C)Community A and B would have equal values for the Shannon index.
D)Cannot predict the result based on this information.

Question 23

You decide to volunteer at a community garden and are assigned to tend six equally sized vegetable beds.Three of the beds contain only tomato plants,while the other three contain tomatoes as well as snow peas,bell peppers,cucumbers,okra,and broccoli.You work hard all summer and fall,tending the plants through insect outbreaks and severe summer storms with wind and hail.You harvest vegetables every three days and start to notice a pattern.The mixed vegetable plots consistently produce 4 pecks (a unit of dry goods measurement)each at every harvest,while the 'tomato only' plots produce between 1-6 pecks each at every harvest.The garden director notices the pattern as well,and knowing you are a biology student,she asks you for an explanation.What concept or hypothesis do you cite in your response?

A)The model of island biogeography
B)The diversity-stability hypothesis
C)The tolerance model
D)The inhibition model
E)The species-productivity hypothesis

Question 24

The number of bird species on islands near Papua New Guinea __________ as one gets farther from Papua New Guinea.

A)increases
B)decreases
C)stays relatively constant
D)does not show a consistent pattern

Question 25

Simberloff and Wilson carried out a famous experiment to study the recolonization by arthropods of small mangrove by islands after the islands were fumigated.One of their findings was

A)The islands never recovered to their pre-fumigation levels of arthropod species richness.
B)Species turnover was high following recolonization.
C)Recolonization rates were identical on all of the islands regardless of distance to the mainland.
D)Arthropod species richness on the islands changed little following recolonization.

Question 26

Predict the rank order of the following locations from lowest species richness to highest species richness,using the latitudinal gradient of species richness to form your prediction:
Temperate forest in North Carolina,steppe in Patagonia (southern tip of South America),rainforest in Costa Rica,boreal forest in Ontario (east-central Canada)

A)steppe in Patagonia,temperate forest in North Carolina,boreal forest in Ontario,rainforest in Costa Rica
B)temperate forest in North Carolina,steppe in Patagonia,rainforest in Costa Rica,boreal forest in Ontario
C)steppe in Patagonia,boreal forest in Ontario,temparate forest in North Carolina,rainforest in Costa Rica
D)rainforest in Costa Rica,temperate forest in North Carolina,boreal forest in Ontario,steppe in Patagonia
E)boreal forest in Ontario,temparate forest in North Carolina,steppe in Patagonia,rainforest in Costa Rica

Question 27

The map above shows the southwestern tip of Alaska,including the Aleutian Islands.True or False: According to MacArthur and Wilson's island biogeography model,Kodiak Island would have more species than Kiska.

Question 28

In the Shannon diversity index,communities with a very uneven distribution of individuals will tend to have a higher H.

Question 29

Species turnover on islands has been observed to be low.What does this suggest about succession on islands?

A)Facilitation is of minor importance on islands.
B)The species that initially colonize islands are random.
C)Succession on most islands proceeds in a relatively predictable manner.
D)The dominant,more important species tend to go extinct during succession on islands.

Question 30

Alders are trees with symbiotic nitrogen fixing bacteria in their roots.This enables alders to be a key part of _________ in recently glaciated areas in Alaska.

A)species extinction
B)emigration
C)primary succession
D)inhibition
E)secondary succession

Question 31

The island biogeography model of Robert MacArthur and
E.O.Wilson predicts a higher value of

Question 32

The time hypothesis suggests communities diversify with age.

Question 33

The species-productivity hypothesis predicts that there would be more species per unit area in the southwestern U.S.than in the Amazon rainforest.

Question 34

Support for the succession mechanism of tolerance is found in research on plant communities that shows

A)that plants release toxins that prevent other species from establishing.
B)succession is random and cannot be predicted by existing species.
C)climax communities rarely form.
D)succession is determined largely by species that exist in the ground as seeds or old roots.
E)competition-tolerant species colonize first.

Question 35

A forest community consists of not only the trees and shrubs,but also the animals and microorganisms.