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Chapter 16
1. A set of species that have similar ways of making their living make up a __________.
Answer: guild
2. In most ecological communities, we find
a) more rare species than moderately common or very common ones.
b) more very common species than moderately common or rare ones.
c) more moderately common species than rare or very common ones.
d) roughly equal proportions of rare, moderately common, and very common species.
e) no rare species – apparently “rare” species are artifacts of incomplete sampling.
Answer: C
3. A simple tree community consists of 4 maples, 3 oaks, and 1 alder. The species
richness of this community is
a) 0.42.
b) 0.97.
c) 1.5.
d) 3.
e) not possible to calculate from the data given.
Answer: D
4. A simple tree community consists of 4 maples, 3 oaks, and 1 alder. The ShannonWiener diversity of this community is
a) 0.42.
b) 0.97.
c) 1.5.
d) 3.
e) not possible to calculate from the data given.
Answer: B
5. Higher species evenness in a community can be measured by a shallower slope on a
rank-abundance curve.
Answer: T
6. Estimates of the number of species present in a community
a) are not affected by the sampling effort devoted to estimation.
b) usually require only limited effort by ecologists.
c) can usually be made more easily by sampling only a single indicator taxon.
d) are all that is necessary to calculate species diversity.
e) must, to be useful, be based on standardized sampling techniques.
Answer: E
7. Robert MacArthur’s study of forest warblers suggested that
a) fewer warbler species can survive in more complex habitats.
b) warbler species diversity increases with habitat complexity.
c) warbler species diversity decreases with habitat complexity.
d) most warblers have rather similar foraging niches.
e) none of the above
Answer: B
8. Niches of single-celled algae, such as diatoms, seem most often to be distinguished by
their requirements for
a) different combinations of inorganic nutrients.
b) different light environments.
c) different water-flow environments.
d) different water temperatures.
e) Most single-celled algae have indistinguishable niches.
Answer: A
9. Concentrations of inorganic nutrients typically don’t vary much across the surface of a
single lake.
Answer: F
10. In terrestrial soils, local patches with high water availability and local patches with
high nitrate availability often show rather little overlap.
Answer: T
11. In the Amazon forest, slight changes in soil properties tend to be correlated with
a) similarly slight differences in plant communities.
b) no detectable differences in plant communities.
c) dramatic differences in plant communities.
d) dramatic differences in plant communities only if the soil property in question is
moisture.
e) dramatic differences in plant communities only if the soil property in question is
bedrock type.
Answer: C
12. In Carl Jordan’s studies of Amazon forest diversity, the highest tree diversity was
found on soils with
a) very high fertility.
b) moderate fertility.
c) very low fertility.
d) either high or low, but not moderate, fertility.
e) There was no relationship between diversity and soil fertility.
Answer: C
13. In soil and water fertilization experiments, increasing fertilization tends to reduce the
number of limiting resources for plant growth until a single resource limits growth of all
species. This “ultimate” limiting resource tends to be
a) carbon.
b) oxygen.
c) phosphorus.
d) nitrogen.
e) light.
Answer: E
14. A relatively discrete ecological event that kills or damages organisms or alters the
physical or biological environment is called a __________.
Answer: disturbance
15. Joseph Connell’s “intermediate disturbance hypothesis” proposes that
a) species diversity is highest at intermediate frequencies of disturbance.
b) species diversity is lowest at intermediate frequencies of disturbance.
c) population growth rates are highest at intermediate frequencies of disturbance.
d) competitive exclusion is fastest at intermediate levels of disturbance.
e) none of the above
Answer: A
16. Winter storms can affect diversity on intertidal boulders because
a) cold water temperatures kill algae and invertebrates.
b) some invertebrates are more vulnerable than others to being dislodged by currents.
c) dessication of exposed invertebrates by unusually high winds is an important source of
mortality.
d) strong storm waves overturn boulders and thereby accelerate competitive exclusion.
e) strong storm waves overturn boulders and thereby remove competitive dominants.
Answer: E
17. In lake sediment records from rain forests in the Darien region of Panama, which of
the following increase at the onset of Native American agricultural use, 4,000 years ago?
a) corn pollen
b) particulate carbon
c) nitrate levels
d) all of the above
e) both (a) and (b)
Answer: E
18. We have good evidence of human disturbance in the New World tropics beginning
approximately
a) 400 years ago.
b) 4,000 years ago.
c) 11,000 years ago.
d) 110,000 years ago.
e) 3 million years ago.
Answer: C
19. European chalk grasslands
a) were a common habitat type before being largely destroyed by human disturbance.
b) have only become common since human disturbance intensified about 10,000 years
ago.
c) grow on thick, fertile soils associated with deeply buried chalk deposits.
d) are a very low diversity habitat.
e) are often destroyed by farmers planting crops.
Answer: B
20. Dominance of chalk grasslands by the grass Brachypodium is increased by
a) protection of grasslands in undisturbed nature reserves.
b) early summer mowing for hay.
c) cessation of fertilizer application.
d) grazing by cattle and sheep.
e) none of the above
Answer: A