Exam 54: Community Ecology

Use the following diagram of a hypothetical food web to answer the question. The arrows represent the transfer of energy between the various trophic levels. Which letter represents an organism that could only be a primary consumer?

Use the figure to answer the following question. What conclusion can you draw from the figure?

Recall that 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 result should we expect Gleason had a more accurate view of communities than did Clement's hypothesis?

Which of the following could qualify as a top-down control on a grassland community?

Food chains are sometimes short because ________.

According to bottom-up and top-down control models of community organization, which of the following expressions would imply that an increase in the size of a carnivore (C) population would negatively impact its prey (P) population, but not vice versa? The arrows between species indicate a negative impact toward the population at the arrowhead.

Use the figures to answer the following question. In this experiment, Balanus was removed from the habitat shown on the left. Which of the following statements is a valid conclusion of this experiment?

In terms of community ecology, why are pathogens often more virulent now than in the past?

The feeding relationships among the species in a community determine the community's

Which of the following studies would a community ecologist undertake to learn about competitive interactions? I.selectivity of nest sites among cavity-nesting songbirds II. the grass species preferred by grazing pronghorn antelope and bison III.stomach analysis of brown trout and brook trout in streams where they coexist

Some birds follow moving swarms of army ants in the tropics. As the ants march along the forest floor hunting insects and small vertebrates, birds follow and pick off any insects or small vertebrates that fly or jump out of the way of the ants. This situation is an example of what kind of species interaction between the birds and the ants?

Which of the following studies would shed light on the mechanism of spread of H5N1 virus from Asia to North America?

Scientists interested in how populations interact within communities are attempting to determine the species diversity of an island under study. What kind of data would be most helpful to the scientists in determining diversity?

Use the figures to answer the following question. According to the Shannon Diversity Index, which of the five blocks above, with each containing 36 squares, would show the greatest diversity? The different shades represent different species, and more squares of a shade represent higher abundance.

Predators that are keystone species can maintain species diversity in a community if they

According to the island equilibrium model, species richness would be greatest on an island that is

Why do moderate levels of disturbance result in an increase in community diversity?

There are more species in tropical areas than in places more distant from the equator. This is probably a result of ________.

Use the figure to answer the following question. In the figure, species A through F are found among four communities, with the number of circles representing their abundance. Which community has the highest species richness but does not have the highest diversity overall because of the relative abundance of the different species?

Elephants are not the most abundant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands are converted to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following statements describes why elephants are the keystone species in this scenario?