According to the generalized species-area curve, when habitat is reduced to 50% of its original size, approximately of the species once present there will be lost.a. 10%;b. 25%;c. 50%;d. 90%;e. it is impossible to estimate the percentage

The feeding relationships among the species in a community determine the community'sa. secondary succession.b. ecological niche.c. species richness.d. trophic structure.

Based on the intermediate disturbance hypothesis, a community's species diversity is increased bya. frequent massive disturbance.b. stable conditions with no disturbance.c. moderate levels of disturbance.d. human intervention to eliminate disturbance.

According to the island equilibrium model, species richness would be greatest on an island that isa. large and remote.b. small and remote.c. large and close to a mainland.d. small and close to a mainland.

Pioneer species tend to have high and lower survivorship.

Predators that are keystone species can maintain species diversity in a community if theya. competitively exclude other predators.b. prey on the community's dominant species.c. reduce the number of disruptions in the community.d. prey only on the least abundant species in the community.

Which of the following organisms is mismatched with its trophic level?a. algae—producerb. phytoplankton—primary consumerc. carnivorous fish larvae—secondary consumerd. eagle—tertiary or quaternary consumer

Food chains are sometimes short becausea. only a single species of herbivore feeds on each plant species.b. local extinction of a species causes extinction of the other species in its food chain.c. most of the energy in a trophic level is lost as energy passes to the next higher level.d. most producers are inedible.

Which of the following best illustrates ecological succession?a. A mouse eats seeds, and an owl eats the mouse.b. Decomposition in soil releases nitrogen that plants can use.c. Grasses grow in a deserted field, followed by shrubs and then trees.d. Imported pheasants increase in numbers, while local quail disappear.