Exam 56: Communities

Two species of mice coexist in a community at approximately equal population sizes.A top predator is removed from this community.Quickly, the population size of mouse species A increases, while that of mouse species B decreases.What does this suggest about the species interactions in this community?

An ecological community has existed for a long time, operating in ways that conform with the lottery (neutral) model.Individuals of different species have obtained resources randomly, by being in the "right place at the right time." A new animal species immigrates into the community.This species is a predator and (compared with others in the community) is aggressive at seeking out prey.How is this new species likely to affect community function?

Two species in a community compete for the same resource.Species A maintains a significantly larger population.However, after a several-year drought, species A declines and species B begins to increase its population size.The two species are carrying out an interaction known as

A tornado rips through an area of the Midwest.Its winds destroy many trees, fields, and crops.Heavy rains flood lowland areas.This situation would be described ecologically as a

A coral reef community was destroyed by a combination of dynamiting and poison to harvest fish.The reef area has recently been declared off-limits for fishing, and a conservation group hopes to restore the reef to its initial state.An ecologist thinks the group is unlikely to achieve this goal.Assuming that environmental conditions (such as temperature and acidity) remain the same, what factor is the ecologist most likely considering that would prevent restoration of the reef?

Wetland A has four species of frogs, present in the following numbers of individuals: 10, 10, 10, and 2.Wetland B has five species of frogs, present in the following numbers: 10, 10, 10, 10, and 10.What can be said about frog species richness and species evenness in the two wetlands?

Primary succession is most likely to occur after a(n)