Chapter 43

According to the U.S. Endangered Species Act (ESA), the difference between an endangered species and a threatened one is that A) an endangered species is closer to extinction. B) a threatened species is closer to extinction. C) threatened species are endangered species outside the U.S. borders. D) endangered species are mainly tropical. E) only endangered species are vertebrates.

A

As the climate changes because of global warming, species' ranges of plants in the Northern Hemisphere may move northward, using effective reproductive adaptations to disperse their seeds. The trees that are most likely to avoid extinction in such an environment are those that A) have seeds that are easily dispersed by wind or animals. B) have thin seed coats. C) produce well-provisioned seeds. D) have seeds that become viable only after a forest fire. E) disperse many seeds in close proximity to the parent tree.

A

Of the following ecosystem types, which have been impacted the most by humans? A) wetland and riparian B) open and benthic ocean C) desert and high alpine D) taiga and second-growth forests E) tundra and arctic

A

Of the following statements about protected areas that have been established to preserve biodiversity, which one is not correct? A) About 25% of Earth's land area is now protected. B) National parks are one of many types of protected areas. C) Most protected areas are too small to protect species. D) Management of a protected area should be coordinated with management of the land surrounding the area. E) It is especially important to protect biodiversity hot spots.

A

The biggest challenge that Costa Rica will likely face in its dedication to conservation and restoration in the future is A) the pressures of its growing population. B) its small size (as a country), which may not be able to maintain large enough reserves. C) the potential for disturbance of sensitive species in reserves by ecotourists. D) spread of disease and parasites via corridors from neighboring countries. E) the large number of Costa Rican species already in the extinction vortex.

A

The concept of sustainable development emphasizes A) the needs of future generations. B) trade between all nations of the world. C) the importance of developing the arts. D) the fastest ways to economic prosperity. E) the need for national government action.

A

The primary difference between the small-population approach (S-PA) and the declining- population approach (D-PA) to biodiversity recovery is A) S-PA is interested in bolstering the genetic diversity of a threatened population rather than the environmental factors that caused the population's decline. B) S-PA kicks in for conservation biologists when population numbers fall below 500. C) D-PA would likely involve bringing together individuals from scattered small populations to interbreed in order to promote genetic diversity. D) S-PA would investigate and eliminate all of the human impacts on the habitat of the species being studied for recovery. E) D-PA would use recently collected population data to calculate an extinction vortex.

A

The use of DDT as an insecticide in the United States has been outlawed since 1971, yet is still a problem for certain top-level carnivores in the United States. Which of the following choices best explains this apparent incongruity? A) DDT is still used for mosquito control in tropical countries, and certain migratory predators can be affected by a seasonal biomagnification. B) DDT is persistent in the environment, and all of the pre-1971 DDT is still available in toxic form to poison top-level carnivores. C) Pre-1971 DDT has been deposited in certain habitats, particularly wetlands and estuaries, so predators in these ecosystems are vulnerable to biomagnifications of DDT. D) Whereas most DDT-susceptible species have become resistant to persistent DDT, others are still vulnerable. E) All of the options are correct.

A

What is the biological significance of genetic diversity between populations? A) Genes for adaptive traits to local conditions make microevolution possible. B) The population that is most fit would survive by competitive exclusion. C) Genetic diversity allows for species stability by preventing speciation. D) Isolated populations become more fit. E) Diseases and parasites are not spread between separated populations.

A

Which of the following is a consequence of biological magnification? A) Toxic chemicals in the environment pose greater risk to toplevel predators than to primary consumers. B) Populations of top-level predators are generally smaller than populations of primary consumers. C) The biomass of producers in an ecosystem is generally higher than the biomass of primary consumers. D) Only a small portion of the energy captured by producers is transferred to consumers. E) The amount of biomass in the producer level of an ecosystem decreases if the producer turnover time increases.

A

Which of the following nations has become a world leader in the establishment of zoned reserves? A) Costa Rica B) Canada C) China D) United States E) Mexico

A

What is caused by excessive nutrient runoff into aquatic ecosystems? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication

E

Agricultural lands frequently require nutrient augmentation because A) nitrogen-fixing bacteria are not as plentiful in agricultural soils because of the use of pesticides. B) the nutrients that become the biomass of plants are not cycled back to the soil on lands where they are harvested. C) land that is available for agriculture tends to be nutrient-poor. D) grains raised for feeding livestock must be fortified, and thus require additional nutrients. E) cultivation of agricultural land inhibits the decomposition of organic matter.

B

Brown-headed cowbirds utilize fragmented forests effectively by A) feeding on the fruits of shrubs that tend to grow at the forest/open-field interface. B) parasitizing the nests of forest birds, and feeding on open-field insects. C) roosting in forest trees, and nesting in grassy fields. D) outcompeting other songbird species in fragmented communities. E) using forest cover to escape from predators in their normal grassland habitat.

B

If global warming continues at its present rate, which biomes will likely take the place of the coniferous forest (taiga)? A) tundra and polar ice B) temperate broadleaf forest and grassland C) desert and chaparral D) tropical forest and savanna E) chaparral and temperate broadleaf forest

B

Managing southeastern forests specifically for the red-cockaded woodpecker A) required the growth of a dense understory of trees and shrubs. B) contributed to greater abundance and diversity of other forest bird species. C) caused other species of songbird to decline. D) involved strict fire-suppression measures. E) involved the creation of fragmented forest habitat.

B

Overexploitation encourages extinction and is most likely to affect A) animals that occupy a broad ecological niche. B) large animals with low intrinsic reproductive rates. C) most organisms that live in the oceans. D) terrestrial organisms more than aquatic organisms. E) edge-adapted species.

B

The introduction of the brown tree snake in the 1940s to the island of Guam has resulted in A) eradication of non-native rats and other undesirable/pest species. B) the extirpation of many of the island's bird and reptile species. C) a good lesson in biological control. D) a new species of hybrids from crossbreeding with a native snake species. E) its failure to compete with native species and its quick elimination from the island.

B

The most serious consequence of a decrease in global biodiversity would be the A) increase in global warming and thinning of the ozone layer. B) potential loss of ecosystem services on which people depend. C) increase in the abundance and diversity of edge-adapted species. D) loss of sources of genetic diversity to preserve endangered species. E) loss of species for use as crops.

B

The word triage originated during World War I and was first used by French doctors in prioritizing patients based on the severity of their wounds, because there were more wounded soldiers in need of urgent care than there were resources to treat them. Conservation biologists have to make similar determinations with degraded ecosystems. Which of the following is the most important consideration when it comes to managing for maintenance of biodiversity? A) identifying large, high-profile vertebrates first, because steps to saving them would be most recognized by the public B) determining which species is most important for conserving biodiversity as a whole C) replanting suitable habitat for fauna D) assessing the economic costs and the gains for society E) maintaining optimum size of all populations in the ecosystem

B

What is the biggest problem with selecting a site for a preserve? A) There is always a conflict about use of land set aside for preservation. B) Making a proper selection is difficult because the current environmental conditions of almost any site may change in the future because of climate change or other factors. C) Keystone species are difficult to identify in potential preserve sites. D) Only lands that are not useful to human activities are available for preserves. E) Most of the best sites are inaccessible by land transportation, so making roads to them is often prohibitively expensive.

B

Which of the following best illustrates human efforts to improve environmental sustainability? A) rerouting major highways around cities to avoid traffic congestion B) increasing our reliance on renewable sources of energy C) upgrading computers every few years to improve performance D) converting automobiles from gasoline to natural gas as a new source of fuel

B

Which of the following investigations would shed the most light on the future distribution of organisms in temperate regions that are faced with climate change? A) Remove, to the mineral soil, all of the organisms from an experimental plot and monitor the colonization of the area over time in terms of both species diversity and abundance. B) Look at the climatic changes that occurred since the last ice age and how species redistributed as glaciers melted, then make predictions on future distribution in species based on past trends. C) Compare and contrast the flora and fauna of warm/cold/dry/wet climates to shed light on how they evolved to be suited to their present-day environment. D) Quantify the impact of humankind's activities on present-day populations of threatened and endangered species to assess the rate of extirpation and extinction. E) There is no scientific investigation that can help make predictions on the future distribution of organisms.

B

Which of the following is true about the current research regarding forest fragmentation? A) Fragmented forests support a greater biodiversity because they result in the combination of forest-edge species and forest-interior species. B) Fragmented forests support a lesser biodiversity because the forested-adapted species leave, and only the edge and open-field species can occupy fragmented forests. C) Fragmented forests are the goal of conservation biologists who design wildlife preserves. D) Harvesting timber that results in forest fragmentation results in less soil erosion. E) The disturbance of timber extraction causes the species diversity to increase because of the new habitats created.

B

Which of the following species was driven to extinction by overexploitation by hunters/fishermen? A) African elephant B) the great auk C) North American bluefin tuna D) flying foxes E) American bison

B

Which of the following terms includes all of the others? A) species diversity B) biodiversity C) genetic diversity D) ecosystem diversity E) species richness

B

According to the small-population approach, what would be the best strategy for saving a population from extirpation? A) determining the minimum viable population size by taking into account the effective population size B) establishing a nature reserve to protect its habitat C) introducing individuals from other populations to increase genetic variation D) determining and remedying the cause of its decline E) reducing the population size of its predators and competitors

C

Although extinction is a natural process, current extinctions are of concern to environmentalists because A) more animals than ever before are going extinct. B) most current extinctions are caused by introduced species. C) the rate of extinction is higher than background extinction rates. D) current extinction is primarily affecting plant diversity. E) None of the options are correct.

C

Biodiversity hot spots are not necessarily the best choice for nature preserves because A) hot spots are situated in remote areas not accessible to wildlife viewers. B) their ecological importance makes land purchase very expensive. C) a hot spot for one group of organisms may not be a hot spot for another group. D) hot spots are designated by the abiotic factors present, not the biotic factors. E) designated hot spots change on a daily basis.

C

Estimates of current rates of extinction A) indicate that we have reached a state of stable equilibrium in which speciation rates equal extinction rates. B) suggest that one-half of all animal and plant species may be gone by the year 2100. C) indicate that rates may be greater than the mass extinctions at the close of the Cretaceous period. D) indicate that only 1% of all of the species that have ever lived on Earth are still alive. E) suggest that rates of extinction have decreased globally.

C

Extinction is a natural phenomenon. It is estimated that 99% of all species that ever lived are now extinct. Why then do we say that we are now experiencing an extinction (loss of biodiversity) crisis? A) Humans are ethically responsible for protecting endangered species. B) Scientists have finally identified most of the species on Earth and are thus able to quantify the number of species becoming extinct. C) The current rate of extinction is high and human activities threaten biodiversity at all levels. D) Humans have greater medical needs than at any other time in history, and many potential medicinal compounds are being lost as plant species become extinct. E) Most biodiversity hot spots have been destroyed by recent ecological disasters.

C

How are movement corridors potentially harmful to certain species? A) They increase inbreeding. B) They promote dispersion. C) They spread disease and parasites. D) They increase genetic diversity. E) They allow seasonal migration.

C

How is habitat fragmentation related to biodiversity loss? A) Less carbon dioxide is absorbed by plants in fragmented habitats. B) In fragmented habitats, more soil erosion takes place. C) Populations of organisms in fragments are smaller, and thus more susceptible to extinction. D) Animals are forced out of smaller habitat fragments. E) Fragments generate silt that negatively affects sensitive river and stream organisms.

C

Invasive species are introduced by humans to new geographic locations and A) are successful in colonizing a novel area. B) spread because they encounter none of their natural predators. C) All of the choices are correct. D) can outcompete and displace native species for biotic and abiotic resources. E) are usually considered pests by ecologists.

C

Relatively small geographic areas with high concentrations of endemic species and a large number of endangered and threatened species are known as A) endemic sinks. B) critical communities. C) biodiversity hot spots. D) endemic metapopulations. E) bottlenecks.

C

Review the formula for effective population size. Imagine a population of 1,000 small rodents. Of these, 300 are breeding females, 300 are breeding males, and 400 are nonbreeding juveniles. What is the effective population size? A) 1,000 B) 1,200 C) 600 D) 400 E) 300

C

The main goal of sustainable development is to A) involve more countries in conservation efforts. B) use only natural resources in the construction of new buildings. C) use natural resources such that they do not decline over time. D) reevaluate and re-implement management plans over time.

C

The success with which plants extend their range northward following glacial retreat is best determined by A) whether there is simultaneous migration of herbivores. B) their tolerance to shade. C) their seed dispersal rate. D) their size. E) their growth rate.

C

What causes extremely high levels of toxic chemicals in fish-eating birds? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication

C

What term did E. O. Wilson coin for our innate appreciation of wild environments and living organisms? A) bioremediation B) bioethics C) biophilia D) biophobia E) landscape ecology

C

Which of the following best illustrates the sustainable use of a resource? A) Coal mines in West Virginia remove the tops of mountains to extract large amounts of coal. B) Fishing industries improve their methods and now remove more than 90% of the fish in a region. C) Huge windmills in Texas are able to capture 50% of the wind energy in a specific region. D) Corporations are converting their company automobiles from gasoline to cheaper natural gas.

C

Which of the following ecological locations has the greatest species diversity? A) tundra B) deciduous forests C) tropical rain forest D) grasslands E) islands

C

Which of the following is consistent with forest fragmentation research? A) Productivity is the same in both fragmented forests and forest interiors. B) Edge communities consistently have low species diversity. C) Forest-interior species show declines in small patch communities. D) New-edge species that migrate in do not seem to compete with forest species and often increase biodiversity in fragmented forests. E) Species diversity is always lower in fragmented forests when compared to forest interiors in the same region.

C

Which of the following is most key to understanding the demographic transition in human population growth? A) education on global famine B) improved worldwide health care C) voluntary reduction of family size D) improved sanitary conditions in the world's hospitals E) reduction of casualties of war

C

Which of the following strategies would most rapidly increase the genetic diversity of a population in an extinction vortex? A) Capture all remaining individuals in the population for captive breeding followed by reintroduction to the wild. B) Establish a reserve that protects the population's habitat. C) Introduce new individuals transported from other populations of the same species. D) Sterilize the least fit individuals in the population. E) Control populations of the endangered population's predators and competitors.

C

Which one of the following is the most sustainable source of energy? A) natural gas used to heat homes B) gasoline used to run cars C) hydroelectric dams D) a coal power plant

C

Which statement is true with regard to human population growth? A) It is at a zero reproduction rate. B) Its rate of increase continues to grow at an exponential rate. C) Its rate of growth is slowing. D) Its rate of growth is increasing. E) There is no scientific prediction that can be made about human population growth.

C

According to most conservation biologists, the single greatest threat to global biodiversity is A) chemical pollution of water and air. B) stratospheric ozone depletion. C) overexploitation of certain species. D) alteration or destruction of the physical habitat. E) global climate change resulting from a variety of human activities.

D

How might the extinction of some Pacific Island bats called "flying foxes" threaten the survival of over 75% of the tree species in those islands? A) wetland and riparian B) open and benthic ocean C) desert and high alpine D) taiga and second-growth forests E) tundra and arctic

D

One characteristic that distinguishes a population in an extinction vortex from most other populations is that A) its habitat is fragmented. B) it is a rare, top-level predator. C) its effective population size is much lower than its total population size. D) its genetic diversity is very low. E) it is not well adapted to edge conditions.

D

The long-term problem with red-cockaded woodpecker habitat intervention in the southeastern United States is A) the only habitat that can support their recovery is large tracts of mature oak forest. B) the mature pine forests in which they live cannot ever be subjected to forest fire. C) all of the appropriate red-cockaded woodpecker habitat has already been logged or converted to agricultural land. D) the social organization of the red-cockaded woodpecker precludes the dispersal of reproductive individuals. E) what habitat remains for the red-cockaded woodpecker does not contain trees suitable for nest-cavity construction.

D

The main cause of the increase in the amount of CO2 in Earth's atmosphere over the past 150 years is A) increased worldwide primary production. B) increased worldwide standing crop. C) an increase in the amount of infrared radiation absorbed by the atmosphere. D) the burning of larger amounts of wood and fossil fuels. E) additional respiration by the rapidly growing human population.

D

What is a critical load? A) the amount of nutrient augmentation necessary to bring a depleted habitat back to its former level B) the level of a given toxin in an ecosystem that is lethal to 50% of the species present C) the maximum abundance level of a particular species, beyond which additional numbers will degrade a habitat D) the amount of added nutrient that can be absorbed by plants without damaging ecosystem integrity E) the number of predators an ecosystem can support that effectively culls prey populations to healthy levels

D

Which of the following conditions is the most likely indicator of a population in an extinction vortex? A) The population is geographically divided into many populations. B) The species in question is found only in small, stable pockets of its former range. C) The effective population size of the species falls below 500. D) Genetic measurements indicate a loss of genetic variation over time. E) The population is connected only by corridors.

D

Which of the following examples poses the greatest potential threat to biodiversity? A) replanting, after a clear cut, a monoculture of Douglas fir trees on land that consisted of old- growth Douglas fir, western cedar, and western hemlock B) allowing previously used farmland to go fallow and begin to fill in with weeds and then shrubs and saplings C) trapping and relocating large predators, such as mountain lions, that pose a threat as they move into areas of relatively dense human populations D) importing an Asian insect into the United States to control a weed that competes with staple crops E) releasing sterilized rainbow trout to boost the sport fishing of a river system that contains native brook trout

D

Which of the following is the most direct threat to biodiversity? A) increased levels of atmospheric carbon dioxide B) the depletion of the ozone layer C) overexploitation of selected species D) habitat destruction E) zoned reserves

D

Which of the following provides the best evidence of a biodiversity crisis? A) the incursion of a non-native species B) increasing pollution levels C) decrease in regional productivity D) high rate of extinction E) climate change

D

Which of the following refers to the reflecting and absorption of infrared radiation by atmospheric methane, carbon dioxide, and water? A) depletion of ozone layer B) acid precipitation C) biological magnification D) greenhouse effect E) eutrophication

D

Burning fossil fuels releases oxides of sulfur and nitrogen. These air pollutants can be responsible for A) the death of fish in lakes. B) precipitation with a pH as low as 3.0. C) calcium deficiency in soils. D) direct damage to plants by leaching nutrients from the leaves. E) All of the options are correct.

E

If the sex ratio in a population is significantly different from 50:50, then which of the following will always be true? A) The population will enter the extinction vortex. B) The genetic variation in the population will increase over time. C) The genetic variation in the population will decrease over time. D) The effective population size will be greater than the actual population size. E) The effective population size will be less than the actual population size.

E

Introduced species can have deleterious effects on biological communities by A) preying on native species. B) competing with native species for food or light. C) displacing native species. D) competing with native species for space or breeding/nesting habitat. E) All of the options are correct.

E

We should care about loss in biodiversity in the populations of other species because of A) biophilia. B) potential loss of medicines and other products yet undiscovered from threatened species. C) potential loss of genes, some of which may code for proteins useful to humans. D) the risk to global ecological stability. E) All of the options are correct.

E

What is the single greatest threat to biodiversity? A) overharvesting of commercially important species B) introduced species that compete with native species C) pollution of Earth's air, water, and soil D) disruption of trophic relationships as more and more prey species become extinct E) habitat alteration, fragmentation, and destruction

E

Which of the following is a type of research in which a conservation biologist would be involved? A) reestablishing whooping cranes in their former breeding grounds in North Dakota B) studying species diversity and interaction in the Florida Everglades, past and present C) studying the population ecology of grizzly bears in Yellowstone National Park D) determining the effects of hunting white-tailed deer in Vermont E) All of the options are correct.

E

Which of the following life history traits can potentially influence effective population size (Ne)? A) maturation age B) genetic relatedness among individuals in a population C) population size D) gene flow between geographically separated populations E) All of the options are correct.

E