All Related Questions of Ecology

Q: Ecologists are now challenged to study global ecology. The apparent role

Ecologists are now challenged to study global ecology. The apparent role played by humans in changing the global environment makes it imperative that we understand the workings of the earth as a globa...

Q: What evidence is there that variation in atmospheric CO 2 concentration is

What evidence is there that variation in atmospheric CO 2 concentration is linked to variation in global temperatures? In recent years, the governments of most countries of the world have been working...

Q: Darwin (1842) was the first to propose that fringing reefs

Darwin (1842) was the first to propose that fringing reefs, barrier reefs, and atolls are different stages in a developmental sequence that begins with a fringing reef and ends with an atoll. Outline...

Q: How was the amount of food that Gause (1934) provided

How was the amount of food that Gause (1934) provided in his experiment on competition among paramecia related to carrying capacity? In Gause’s experiments on competition, P. aurelia excluded P. cauda...

Q: In his experiments on competition between T. confusum and T.

In his experiments on competition between T. confusum and T. castaneum, Park (1954) found that one species usually excluded the other species but that the outcome depended upon physical conditions. In...

Q: Discuss how mathematical theory, laboratory models, and field experiments have

Discuss how mathematical theory, laboratory models, and field experiments have contributed to our understanding of the ecology of competition. List the advantages and disadvantages of each approach....

Q: Predation is one of the processes by which one organism exploits another

Predation is one of the processes by which one organism exploits another. Others are herbivory, parasitism, and disease. What distinguishes each of these processes, including predation, from the other...

Q: How are manipulation of host behavior by spiny-headed worms and

How are manipulation of host behavior by spiny-headed worms and manipulation of plant growth by the rust Puccinia monoica the same? How are they different? The details of these parasitic interactions...

Q: Predation by one flour beetle species on another can be used as

Predation by one flour beetle species on another can be used as a potent means of interference competition. However, the predatory strategy seems to fail consistently in the presence of the protozoan...

Q: In chapter 14 we have seen how a herbivorous stream insect controls

In chapter 14 we have seen how a herbivorous stream insect controls the density of its food organisms, how a herbivorous moth larva and pathogenic microbes combine to control an introduced cactus popu...

Q: Early work on exploitation focused a great deal of attention on predator

Early work on exploitation focused a great deal of attention on predator-prey relations. However, parasites and pathogens represent a substantial part of the discussions in chapter 14. Is this represe...

Q: Researchers have suggested that predators could actually increase the population density of

Researchers have suggested that predators could actually increase the population density of a prey species heavily infected by a pathogenic parasite (Hudson, Dobson, and Newborn 1992). Explain how pre...

Q: Review the distribution of water among the major reservoirs of the hydrologic

Review the distribution of water among the major reservoirs of the hydrologic cycle. What are the major sources of freshwater? Explain why according to some projections availability of freshwater may...

Q: Explain the roles of food and predators in producing cycles of abundance

Explain the roles of food and predators in producing cycles of abundance in populations of snowshoe hare. Populations of many of the predators that feed on snowshoe hares also cycle substantially. Exp...

Q: What contributions have laboratory and mathematical models made to our understanding of

What contributions have laboratory and mathematical models made to our understanding of predator-prey population cycles? What are the shortcomings of these modeling approaches? What are their advantag...

Q: One of the conclusions that seems justified in light of several decades

One of the conclusions that seems justified in light of several decades of studies of interspecific competition is that competition is a common and strong force operating in nature, but not always a...

Q: List and briefly describe mutualistic relationships that seem to contribute to the

List and briefly describe mutualistic relationships that seem to contribute to the ecological integrity of the biosphere.

Q: What contributions do mycorrhizal fungi make to their plant partners? What

What contributions do mycorrhizal fungi make to their plant partners? What do plants contribute in return for the services of mycorrhizal fungi? How did Hardie (1985) demonstrate that mycorrhizae impr...

Q: Outline the experiments of Johnson (1993), which she designed to

Outline the experiments of Johnson (1993), which she designed to test the possibility that artificial fertilizers may select for less mutualistic mycorrhizal fungi. What evidence does Johnson present...

Q: Explain how mycorrhizal fungi may have evolved from ancestors that were originally

Explain how mycorrhizal fungi may have evolved from ancestors that were originally parasites of plant roots. Do any of Johnson’s results (1993) indicate that present-day mycorrhizal fungi may act as p...

Q: Janzen (1985) encouraged ecologists to take a more experimental approach

Janzen (1985) encouraged ecologists to take a more experimental approach to the study of mutualistic relationships. Outline the details of Janzen’s own experiments on the mutualistic relationship betw...

Q: Inouye and Taylor’s study (1979) of the relationship between ants

Inouye and Taylor’s study (1979) of the relationship between ants and the aspen sunflower, Helianthella quinquenervis, provides a reasonable representative of temperate ant-plant protection mutualisms...

Q: How are coral-centered mutualisms similar to plant-centered mutualisms

How are coral-centered mutualisms similar to plant-centered mutualisms? How are they different? The exchanges between mutualistic partners in both systems revolve around energy, nutrients, and protect...

Q: How did the studies of Douglas and Brunner complement the earlier studies

How did the studies of Douglas and Brunner complement the earlier studies of Clausen, Keck, and Hiesey?

Q: Outline the benefits and costs identified by Keeler’s (1981, 1985

Outline the benefits and costs identified by Keeler’s (1981, 1985) cost-benefit model for facultative ant-plant mutualism. From what perspective does Keeler’s model view this mutualism? From the persp...

Q: We included spatial refuges, predator satiation, and size in our

We included spatial refuges, predator satiation, and size in our discussions of the role played by refuges in the persistence of exploited species. How could time act as a refuge? Explain how natural...

Q: Outline how the honeyguide-human mutualism could have evolved from an

Outline how the honeyguide-human mutualism could have evolved from an earlier mutualism between honeyguides and honey badgers. In many parts of Africa today, people have begun to abandon traditional h...

Q: What is the difference between a community and a population? What

What is the difference between a community and a population? What are some distinguishing properties of communities? What is a guild? Give examples. What is a plant life-form? Give examples.

Q: How does feeding by urchins, which prey on young corals,

How does feeding by urchins, which prey on young corals, improve establishment by young corals? Use a diagram outlining interactions among urchins, corals, and algae to help in the development of your...

Q: Suppose you are a biologist working for an international conservation organization concerned

Suppose you are a biologist working for an international conservation organization concerned with studying and conserving biological diversity. On one of your assignments you are sent out to explore t...

Q: What are species richness and species evenness? How does each of

What are species richness and species evenness? How does each of these components of species diversity contribute to the value of the Shannon-Wiener diversity index (H ')? How do species evenness and...

Q: Compare the “trophic” niches of warblers and diatoms as described

Compare the “trophic” niches of warblers and diatoms as described by MacArthur (1958) and Tilman (1977). Why is it important that the ecologist be familiar with the niches of study organisms before ex...

Q: Communities in different areas may be organized in different ways. For

Communities in different areas may be organized in different ways. For instance, C. Ralph (1985) found that in Patagonia in Argentina, as foliage height diversity increases, bird species diversity dec...

Q: According to the intermediate disturbance hypothesis, both low and high levels

According to the intermediate disturbance hypothesis, both low and high levels of disturbance can reduce species diversity. Explain possible mechanisms producing this relationship. Include trade-offs...

Q: What is the Hardy-Weinberg principle? What is Hardy-

What is the Hardy-Weinberg principle? What is Hardy- Weinberg equilibrium? What conditions are required for Hardy-Weinberg equilibrium?

Q: Winemiller (1990) deleted “weak” trophic links from one

Winemiller (1990) deleted “weak” trophic links from one set of food webs that he described for fish communities in Venezuela (see fig. 17.3). What was h...

Q: What is a keystone species? Paine (1966, 1969)

What is a keystone species? Paine (1966, 1969) experimented with two sea stars that act as keystone species in their intertidal communities along the west coast of North America and in New Zealand. De...

Q: Explain how the experiments of Lubchenco (1978) showed that feeding

Explain how the experiments of Lubchenco (1978) showed that feeding preferences, population density, and competitive relations among food species all potentially contribute to the influences of “keyst...

Q: When Power (1990) excluded predaceous fish from her river sites

When Power (1990) excluded predaceous fish from her river sites, the density of herbivorous insect larvae (chironomids) decreased. Use the food web described by Power to explain this response.

Q: Using Tscharntke’s food web (1992) shown in figure 17.

Using Tscharntke’s food web (1992) shown in figure 17.5, predict which species would be most affected if you excluded the bird at the top of the web, Parus caeruleus. Wha...

Q: Some paleontologists have proposed that overhunting caused the extinction of many large

Some paleontologists have proposed that overhunting caused the extinction of many large North American mammals at the end of the Pleistocene about 11,000 and 10,000 years ago. The hunters implicated b...

Q: All the keystone species work we have discussed in chapter 17 has

All the keystone species work we have discussed in chapter 17 has concerned the influences of animals on the structure of communities. Can other groups of organism’s act as keystones? What about paras...

Q: The dams that have been built on many rivers often stabilize river

The dams that have been built on many rivers often stabilize river flow by increasing flows below the dam during droughts and decreasing the amount of flooding during periods of high rainfall. Using t...

Q: Humans have been living in the tropical rain forests of the New

Humans have been living in the tropical rain forests of the New World for at least 11,000 years. During this period, disturbance by humans has been a part of these tropical rain forests. Use the inter...

Q: Why do introduced predators possibly threaten the species diversity of a community

Why do introduced predators possibly threaten the species diversity of a community such as Lake Victoria, while indigenous predators do not? Think in evolutionary timescales as you develop your answer...

Q: Review the Hardy-Weinberg equilibrium equation. What parts of the

Review the Hardy-Weinberg equilibrium equation. What parts of the equation represent gene frequencies? What elements represent genotype frequencies and phenotype frequencies? Are genotype and phenotyp...

Q: Population, community, and ecosystem ecologists study structure and process.

Population, community, and ecosystem ecologists study structure and process. However, they focus on different natural characteristics. Contrast the important structures and processes in a forest from...

Q: M. Huston (1994b) pointed out that the well-

M. Huston (1994b) pointed out that the well-documented pattern of increasing annual primary production from the poles to the equator is strongly influenced by the longer growing season at low latitude...

Q: Many migratory birds spend approximately half the year in temperate forests during

Many migratory birds spend approximately half the year in temperate forests during the warm breeding season and the other half of the year in tropical forest. Given the analyses you made in question 2...

Q: Field experiments demonstrate that variation in soil fertility influences terrestrial primary production

Field experiments demonstrate that variation in soil fertility influences terrestrial primary production. However, we cannot say that nutrients exert primary control. That role is still attributed to...

Q: Shaver and Chapin (1986) pointed out that though the tundra

Shaver and Chapin (1986) pointed out that though the tundra ecosystems they studied consistently increased primary production in response to fertilization, individual species and growth forms showed m...

Q: Compare the pictures of trophic structure that emerged from our discussions of

Compare the pictures of trophic structure that emerged from our discussions of food webs in chapter 17 with those in chapter 18. What are the strengths of each perspective? What are their limitations?...

Q: Suppose you are studying a community of small mammals that live on

Suppose you are studying a community of small mammals that live on the boundary between a riverside forest and a semidesert grassland. One of your concerns is to discover the relative contributions of...

Q: Most of the energy that flows through a forest ecosystem flows through

Most of the energy that flows through a forest ecosystem flows through detritus-based food chains, and the detritus consists mainly of dead plant tissues (e.g., leaves and wood). In contrast, most of...

Q: In chapter 17, we examined the influences of keystone species on

In chapter 17, we examined the influences of keystone species on the structure of communities. In chapter 18, we reviewed trophic cascades. Discuss the similarities and differences between these two c...

Q: In chapter 17, we examined the influences of keystone species on

In chapter 17, we examined the influences of keystone species on the structure of communities. In chapter 18, we reviewed trophic cascades. Discuss the similarities and differences between these two c...

Q: What is genetic drift? Under what circumstances do you expect genetic

What is genetic drift? Under what circumstances do you expect genetic drift to occur? Under what circumstances is genetic drift unlikely to be important? Does genetic drift increase or decrease geneti...

Q: Of all the naturally occurring elements in the biosphere, why have

Of all the naturally occurring elements in the biosphere, why have the cycles of carbon, nitrogen, and phosphorus been so intensively studied by ecologists? (Hint: Think about the kinds of organic mol...

Q: Parmenter and Lamarra (1991) studied decomposition of fish and waterfowl

Parmenter and Lamarra (1991) studied decomposition of fish and waterfowl carrion in a freshwater marsh. During the course of their studies they found that the soft tissues of both fish and waterfowl d...

Q: Review figure 18.2, in which Rosenzweig (1968)

Review figure 18.2, in which Rosenzweig (1968) plotted the relationship between actual evapotranspiration and net primary production. How do you think that decomposition rates change across the same e...

Q: Melillo, Aber, and Muratore (1982) suggested that soil

Melillo, Aber, and Muratore (1982) suggested that soil fertility may influence the rate of decomposition in terrestrial ecosystems. Design an experiment to test this hypothesis. If you test for the ef...

Q: Many rivers around the world have been straightened and deepened to improve

Many rivers around the world have been straightened and deepened to improve conditions for navigation. Side effects of these changes include increased average water velocity and decreased movement of...

Q: Likens and Bormann (1995) found that vegetation substantially influences the

Likens and Bormann (1995) found that vegetation substantially influences the rate of nutrient loss from small stream catchments in the northern hardwood forest ecosystem. How do vegetative biomass and...

Q: McNaughton, Ruess, and Seagle (1988) proposed that grazing

McNaughton, Ruess, and Seagle (1988) proposed that grazing by large mammals increases the rate of nitrogen cycling on the savannas of East Africa. Explain how passing through a large mammal could incr...

Q: The fynbos of South Africa is famous for the exceptional diversity of

The fynbos of South Africa is famous for the exceptional diversity of its plant community. Witkowski (1991) showed that invading Acacia are enriching the fynbos soil with nitrogen. How might enriching...

Q: Kauffman and his colleagues (1993) estimated that burning the tropical

Kauffman and his colleagues (1993) estimated that burning the tropical forest at their study site resulted in the loss of approximately 21 kg per hectare of phosphorus. This quantity is about 11% to 1...

Q: If rates of decomposition are higher in ecosystems with higher nutrient availability

If rates of decomposition are higher in ecosystems with higher nutrient availability, how should nutrient enrichment affect rates of decomposition? Because of its effects on fungal diversity, could nu...

Q: Suppose you are a director of a captive breeding program for a

Suppose you are a director of a captive breeding program for a rare species of animal, such as Siberian tigers, which are found in many zoos around the world but are increasingly rare in the wild. Des...

Q: As we saw in figure  20.5, Johnston and Odum

As we saw in figure  20.5, Johnston and Odum (1956) documented substantial change in the richness of bird species in a successional sequence going from the earliest stages in which the pla...

Q: Would you expect the number of species to remain indefinitely at the

Would you expect the number of species to remain indefinitely at the level shown in figure 20.7? Space on large, stable boulders in Sousa’s study site is dominated by the...

Q: The successional studies in Sycamore Creek produced patterns of variation in diversity

The successional studies in Sycamore Creek produced patterns of variation in diversity that differed significantly from those observed during primary succession at Glacier Bay (see fig.&Ac...

Q: In most studies of forest succession such as that of Reiners and

In most studies of forest succession such as that of Reiners and colleagues (1971) and Oosting (1942), researchers study succession by comparing sites of various ages. This approach is called a “space...

Q: The rapid succession shown by the Sycamore Creek ecosystem is impressive.

The rapid succession shown by the Sycamore Creek ecosystem is impressive. How might natural selection influence the life cycles of the organisms living in Sycamore Creek? Imagine a creek that floods a...

Q: In the studies of mechanisms underlying succession, ecologists have found a

In the studies of mechanisms underlying succession, ecologists have found a great deal of evidence for both facilitation and inhibition. However, they have found little evidence for the tolerance mode...

Q: When Mount St. Helens in Washington erupted in 1980, it

When Mount St. Helens in Washington erupted in 1980, it created a gradient in disturbance. In the pumice plains near the eruption, the devastation was almost total. The extent of disturbance was much...

Q: Ecological succession has been compared to the development of an organism and

Ecological succession has been compared to the development of an organism and the climax community to a kind of superorganism. F. E. Clements (1916, 1936) was the best-known proponent of this idea, an...

Q: Species have come and gone in response to changing global climates during

Species have come and gone in response to changing global climates during the history of the earth. Some of the mass extinctions of the past have resulted in the deaths of over 90% of existing species...

Q: How does landscape ecology differ from ecosystem and community ecology? What

How does landscape ecology differ from ecosystem and community ecology? What questions might an ecosystem ecologist ask about a forest? What questions might a community ecologist ask about the same fo...

Q: How might the distribution of beak sizes in the population differ from

How might the distribution of beak sizes in the population differ from that shown in figure 4.13, if mate choice in the population was random with respect to beak size? FigureÂ&nbs...

Q: How should the area of forest patches in an agricultural landscape affect

How should the area of forest patches in an agricultural landscape affect the proportion of bird species in a community that are associated with forest edge habitats? How should patch area affect the...

Q: The green areas represent forest fragments surrounded by agriculture. Landscapes 1

The green areas represent forest fragments surrounded by agriculture. Landscapes 1 and 2 contain the same total forest area. Which landscape, 1 or 2, will contain more forest interior species? Explain...

Q: How do the positions of patches in a landscape affect the movement

How do the positions of patches in a landscape affect the movement of individuals among habitat patches and among portions of a metapopulation? Again, consider the hypothetical landscapes shown in que...

Q: Consider the options for preserving patches of riverside forest shown in landscapes

Consider the options for preserving patches of riverside forest shown in landscapes 3 and 4. Again, the two landscapes contain the same total area of forest but the patches in the two landscapes diffe...

Q: How do the positions of patches in a landscape affect the movement

How do the positions of patches in a landscape affect the movement of individuals among habitat patches and among portions of a metapopulation? Again, consider the hypothetical landscapes shown in que...

Q: Use fractal geometry and the niche concept (see chapters 9,

Use fractal geometry and the niche concept (see chapters 9, 13, and 16) to explain why the canopy of a forest should accommodate more species of predaceous insects than insectivorous birds. Assume tha...

Q: Analyses such as Milne’s comparison (1993) of bald eagles and

Analyses such as Milne’s comparison (1993) of bald eagles and barnacles demonstrate that organisms of different sizes interact with the environment at very different spatial scales....

Q: How do the activities of animals affect landscape heterogeneity? You might

How do the activities of animals affect landscape heterogeneity? You might use either beaver or human activity as your model. What parallels can you think of between the influence of animal activity o...

Q: Succession seems to lead to predictable changes in community and ecosystem structure

Succession seems to lead to predictable changes in community and ecosystem structure. Predict the characteristics of a frequently disturbed community/ecosystem versus a largely undisturbed community/e...

Q: The following data (corrected from Preston 1962a) give the area

The following data (corrected from Preston 1962a) give the area and number of bird species on islands in the West Indies: The numbers are expressed in two ways: as simple measurements and counts and...

Q: How did the studies of Scott Carroll and his colleagues demonstrate rapid

How did the studies of Scott Carroll and his colleagues demonstrate rapid evolutionary adaptation to introduced soapberry plants? What advantages do a group of organisms, such as soapberry bugs, offer...

Q: Refer to figure 22.5, which MacArthur and Wilson (

Refer to figure 22.5, which MacArthur and Wilson (1963) used to show how isolation affects species richness on islands. Find a detailed map of the Pacific Ocean and locate New Guinea. Next...

Q: We discussed how Diamond (1969) documented immigrations and extinctions on

We discussed how Diamond (1969) documented immigrations and extinctions on the California Channel Islands by comparing his censuses of the birds of the islands with the birds recorded over 50 years ea...

Q: Diamond’s estimates (1969) of numbers of species immigrating and numbers

Diamond’s estimates (1969) of numbers of species immigrating and numbers that became extinct (six versus five) were virtually identical. Is this near equality in numbers of extinctio...

Q: Suppose you are about to study the bird communities on the islands

Suppose you are about to study the bird communities on the islands shown above, which are identical in area but lie at different distances from the mainland. According to the equilibrium model of isla...

Q: Now, suppose you are going to study the bird communities on

Now, suppose you are going to study the bird communities on the islands shown below, which lie equal distances from the mainland but differ in area. According to the equilibrium model of island biogeo...

Q: Review the major hypotheses proposed to explain the higher species richness of

Review the major hypotheses proposed to explain the higher species richness of tropical regions compared to temperate and high-latitude regions. How are each of these hypotheses related to relative ra...

Q: Explain how speciation and extinction rates might be affected by the area

Explain how speciation and extinction rates might be affected by the area of continents. What evidence is there to support your explanation? What does the influence of area on rates of extinction and...

Q: Ricklefs (1987) pointed out that many large-scale contrasts

Ricklefs (1987) pointed out that many large-scale contrasts in species richness and composition cannot be explained by local processes such as competition and predation. Ricklefs proposed that differe...

Q: Most examples of regional and latitudinal variation in species richness cited in

Most examples of regional and latitudinal variation in species richness cited in this chapter have been terrestrial. Consider regional variation in marine biotas. Like birds on land, fish are one of t...

Q: How might a history of exposure to wide environmental fluctuation affect the

How might a history of exposure to wide environmental fluctuation affect the physiological tolerances of intertidal species compared to close relatives in sub tidal and oceanic environments? How might...

Q: How do classical approaches to genetic studies, such as common garden

How do classical approaches to genetic studies, such as common garden experiments, and modern molecular techniques, such as DNA sequencing, complement each other? What are the advantages and disadvant...

Q: How might oxygen concentration of interstitial water be related to the grain

How might oxygen concentration of interstitial water be related to the grain size of the sand or mud sediment? How might the oxygen concentrations of tide pools in sheltered bays compare to those on t...

Q: According to the river continuum model, the organisms inhabiting headwater streams

According to the river continuum model, the organisms inhabiting headwater streams in temperate forest regions depend mainly upon organic material coming into the stream from the surrounding forests....

Q: How could you test the generalization that lake primary production and the

How could you test the generalization that lake primary production and the composition of the biota living in lakes are strongly influenced by the availability of nutrients such as nitrogen and phosph...

Q: Biological interactions may also affect lake systems. How does the recent

Biological interactions may also affect lake systems. How does the recent history of the Great Lakes suggest that the kinds of species that inhabit a lake influence the nature of the lake environment...

Q: Daniel Janzen (1981a, 1981b) proposed that the seeds of

Daniel Janzen (1981a, 1981b) proposed that the seeds of the Guanacaste tree were once dispersed by several species of large mammals that became extinct following the end of the Pleistocene about 10,00...

Q: Draw a typical soil profile, indicating the principal layers, or

Draw a typical soil profile, indicating the principal layers, or horizons. Describe the characteristics of each layer.

Q: Describe global patterns of atmospheric heating and circulation. What mechanisms produce

Describe global patterns of atmospheric heating and circulation. What mechanisms produce high precipitation in the tropics? What mechanisms produce high precipitation at temperate latitudes? What mech...

Q: Use what you know about atmospheric circulation and seasonal changes in the

Use what you know about atmospheric circulation and seasonal changes in the sun’s orientation to earth to explain the highly seasonal rainfall in the tropical dry forest and tropical savanna biomes....

Q: We focused much of our discussion of biomes on their latitudinal distribution

We focused much of our discussion of biomes on their latitudinal distribution. The reasonably predictable relationship among latitude and temperature and precipitation provides a link between latitude...

Q: You probably suggested altitude in response to question 5 because of its

You probably suggested altitude in response to question 5 because of its important influence on climate. Some of the earliest studies of the geographic distribution of vegetation suggested a direct co...

Q: Geologists, atmospheric scientists, and oceanographers have been conducting global-

Geologists, atmospheric scientists, and oceanographers have been conducting global-scale studies for some time. What role will information from these disciplines play in the study of global ecology? W...

Q: Many species of plants and animals that are associated with boreal forests

Many species of plants and animals that are associated with boreal forests also occur on mountains far to the south of the boreal forests. Using what you have learned about microclimates, predict how...

Q: Faced with the complexity of nature, ecologists have divided the field

Faced with the complexity of nature, ecologists have divided the field of ecology into sub disciplines, each of which focuses on one of the levels of organization pictured in figure 1.1. W...

Q: What are the pitfalls of subdividing nature in the way it is

What are the pitfalls of subdividing nature in the way it is represented in figure 1.1? In what ways does figure 1.1 misrepresent nature? Figure 1.1:

Q: What could you do to verify that the distinct feeding zones used

What could you do to verify that the distinct feeding zones used by the warblers studied by MacArthur (see fig.  1.3) are the result of ongoing competition between the different species of...

Q: Although Nalini Nadkarni’s studies of the rain forest canopy addressed a question

Although Nalini Nadkarni’s studies of the rain forest canopy addressed a question related to ecosystem structure, the patterns of nutrient storage in rain forest canopy resulted from the biology of in...

Q: What do the studies of Margaret Davis tell us about the composition

What do the studies of Margaret Davis tell us about the composition of forests in the Appalachian Mountains during the past 12,000 years (see fig. 1.8)? Based on this research, what predic...

Q: During the course of the studies reviewed in this chapter, each

During the course of the studies reviewed in this chapter, each scientist or team of scientists measured certain variables. What major variable studied by Margaret Davis and her research team distingu...

Q: How is the physical environment on mountains at midlatitudes similar to that

How is the physical environment on mountains at midlatitudes similar to that in tropical alpine zones? How do these environments differ?

Q: English and other European languages have terms for four seasons: spring

English and other European languages have terms for four seasons: spring, summer, autumn, and winter. This vocabulary summarizes much of the annual climatic variation at midlatitudes in temperate regi...

Q: Biologists have observed much more similarity in species composition among boreal forests

Biologists have observed much more similarity in species composition among boreal forests and among areas of tundra in Eurasia and North America than among tropical rain forests or among Mediterranean...

Q: To date, which biomes have been the most heavily affected by

To date, which biomes have been the most heavily affected by humans? Which seem to be the most lightly affected? How would you assess human impact? How might these patterns change during this century?...

Q: Imagine a desert beetle that uses behavior to regulate its body temperature

Imagine a desert beetle that uses behavior to regulate its body temperature above 35 8 C. How might this beetle’s use of microclimates created by shrubs, burrows, and bare ground change with the seaso...

Q: How could you change the Lotka-Volterra model of competition we

How could you change the Lotka-Volterra model of competition we discussed in chapter 13 into a model of mutualism? Would the resulting model be a cost-benefit model or a population dynamic model?

Q: The discussion of the research by Margaret Davis and her colleagues did

The discussion of the research by Margaret Davis and her colleagues did not identify the questions that they addressed. What research questions can we infer from the above description of their work?...

Q: What aspects of Nalini Nadkarni’s research identify it as “ecosystem ecology

What aspects of Nalini Nadkarni’s research identify it as “ecosystem ecology”? Give examples of research in forest canopies that would address oth...

Q: How were the warbler studies of Robert MacArthur and those that focused

How were the warbler studies of Robert MacArthur and those that focused on the American redstart similar? How did they differ?

Q: : How does the level of ecological organization an ecologist studies influence

How does the level of ecological organization an ecologist studies influence the questions he or she poses?

Q: While an ecologist may focus on a particular level of ecological organization

While an ecologist may focus on a particular level of ecological organization shown in figure 1.1, might other levels of organization be relevant, for example, does an ecologist studying factors limit...

Q: The Ligons found that most of the young woodhoopoes tended by helpers

The Ligons found that most of the young woodhoopoes tended by helpers were either full siblings or half siblings of the helpers. If full siblings were genetically related to the helpers by an average...

Q: According to Hamilton’s rule, would helpers derive greater benefit through kin

According to Hamilton’s rule, would helpers derive greater benefit through kin selection by contributing the same amount of help toward raising a full sibling or a half sibling?

Q: What are some advantages of Damuth’s strict focus on herbivorous mammals in

What are some advantages of Damuth’s strict focus on herbivorous mammals in his analysis of the relationship between body size and population density (see fig. 9.19)? F...

Q: How might energy and nutrient relations explain the lower population densities of

How might energy and nutrient relations explain the lower population densities of birds compared to comparable-sized mammals (see fig. 9.20)? Figure 9.20:

Q: J. L. Mosser and colleagues (1974) found that

J. L. Mosser and colleagues (1974) found that populations of the bacterium Sulfolobus living at different temperatures had different optimal temperatures for sulfur oxidation. Use natural selection to...

Q: How can energy losses between trophic levels limit the number of trophic

How can energy losses between trophic levels limit the number of trophic levels in an ecosystem?

Q: Is it possible for two consumer populations to have equal biomass but

Is it possible for two consumer populations to have equal biomass but differ in secondary production?

Q: Would secondary production in a stream ecosystem dependent on inputs of detritus

Would secondary production in a stream ecosystem dependent on inputs of detritus from a surround forest change, if detrital inputs to the stream, for example leaves falling from nearby trees, were red...

Q: What is the ecological significance of Frankham’s finding lower genetic variation in

What is the ecological significance of Frankham’s finding lower genetic variation in smaller, isolated island populations?

Q: Why don’t hummingbirds save energy by going into torpor at night even

Why don’t hummingbirds save energy by going into torpor at night even when food supplies are abundant? In other words, what would be a possible disadvantage of routine, nightly torpor?

Q: Why might the frequency of torpor and hibernation be more common among

Why might the frequency of torpor and hibernation be more common among animals in tropical dry forest compared to those living in tropical rain forests?

Q: Why do the managers of captive breeding and reintroduction programs for endangered

Why do the managers of captive breeding and reintroduction programs for endangered species try to maintain high levels of genetic diversity?

Q: According to optimal foraging theory, under what conditions should a predator

According to optimal foraging theory, under what conditions should a predator add a new prey species to its diet?

Q: Do patterns of feeding by bluegills (see fig. 7.

Do patterns of feeding by bluegills (see fig. 7.25) include any evidence that these consumers ignore certain potential prey? Figure 7.25:

Q: Why did Tilman and Cowan plant several pots of each species in

Why did Tilman and Cowan plant several pots of each species in each of their growing conditions?

Q: Figure 5.8 shows how temperature influences the activity of acetyl

Figure 5.8 shows how temperature influences the activity of acetyl cholinesterase in rainbow trout. Assuming that the other enzymes of rainbow trout show similar responses to temperature, how would tr...

Q: How would a queen ant, or other eusocial hymenopteran queen,

How would a queen ant, or other eusocial hymenopteran queen, mating with several males affect the relatedness of workers within a colony? If common in social hymenoptera, how would queens mating with...

Q: What are two major ecological challenges favoring colony living that are shared

What are two major ecological challenges favoring colony living that are shared by leaf-cutter ants and naked mole rats?

Q: What evidence does colony structure offer in support of the idea that

What evidence does colony structure offer in support of the idea that both leaf-cutter ants and naked mole rats must vigorously defend their colonies from predators and invaders?

Q: Of the three populations pictured in figures 10.19, 10

Of the three populations pictured in figures 10.19, 10.20, and 10.21, which is most likely to have a stable age distribution? Figures 10.19: Figures 10.20: Continue to next pagesâ€...

Q: Suppose that you are managing a population of an endangered species that

Suppose that you are managing a population of an endangered species that has been reduced in numbers throughout its historic range and that your goal is to increase the size of the population. What va...

Q: Both R0 and r indicate that the mud turtle population in Ellenton

Both R0 and r indicate that the mud turtle population in Ellenton Bay is in decline. Is there any way that this population could be maintained for many generations even with such negative indicators?...

Q: Can a healthy population that is not in danger of extinction have

Can a healthy population that is not in danger of extinction have an age structure that shows years of reproductive failure?

Q: The last major natural reproduction by Rio Grande cottonwoods, which produced

The last major natural reproduction by Rio Grande cottonwoods, which produced the large number of 40- and 50-year-old trees documented by Howe and Knopf (1991), occurred before the last major dam was...

Q: What are the evolutionary implications of the fact that larger coalitions of

What are the evolutionary implications of the fact that larger coalitions of male lions consist almost entirely of close relatives (see fig. 8.25)? Figure 8.25:

Q: What do you think would have happened to the Galium sylvestre on

What do you think would have happened to the Galium sylvestre on acidic soil if Tansley had continued his experiment for a few more years?

Q: The Applications section reviews how the studies of Bruno Baur and Anette

The Applications section reviews how the studies of Bruno Baur and Anette Baur (1993) have documented the local extinction of the land snail Arianta arbustorum. Their research also shows that these ex...

Q: What does the increase in small granivore populations but lack of response

What does the increase in small granivore populations but lack of response by populations of insectivorous rodents suggest about the nature of competition between rodents in Brown’s...

Q: What factors make coexistence of predators and prey less likely in a

What factors make coexistence of predators and prey less likely in a laboratory setting than in nature?

Q: Why should there be strong selection on periodical cicadas for highly synchronous

Why should there be strong selection on periodical cicadas for highly synchronous emergence?

Q: Why did Brown and colleagues repeat their large granivore experiment (see

Why did Brown and colleagues repeat their large granivore experiment (see fig. 13.24)? Figure 13.24:

Q: Could protecting forests that once burned with regular frequency, due to

Could protecting forests that once burned with regular frequency, due to lightning strikes, lead to reduced plant diversity within a mountain forest landscape of 25 km2  (~10 mi2)?

Q: If disturbance can foster higher species diversity, why is human disturbance

If disturbance can foster higher species diversity, why is human disturbance often (though not always) associated with reduced species diversity?

Q: Bshary studied changes in fish species richness in response to both natural

Bshary studied changes in fish species richness in response to both natural and experimental removals and additions of the cleaner fish Labroides dimidiatus (see fig. 17.18). Why did he no...

Q: In many regions, native pollinator insects seem to be declining.

In many regions, native pollinator insects seem to be declining. Why is this a cause for concern among conservationists and ecologists?

Q: According to the intermediate disturbance hypothesis, could human disturbance sustain higher

According to the intermediate disturbance hypothesis, could human disturbance sustain higher levels of species diversity than in the absence of human disturbance?

Q: In their initial studies, leading to the trophic cascade hypothesis,

In their initial studies, leading to the trophic cascade hypothesis, Stephen Carpenter and his colleagues (1991) found a negative correlation between zooplankton size and phytoplankton primary product...

Q: Butterflies, which are ectothermic and diurnal, are found from the

Butterflies, which are ectothermic and diurnal, are found from the tropical rain forest to the Arctic. They can elevate their body temperatures by basking in sunlight. How would the percentage of time...

Q: Since increased phytoplankton biomass decreases water clarity in lakes, how should

Since increased phytoplankton biomass decreases water clarity in lakes, how should increased fishing pressure on the bass population in a lake ecosystem, such as that pictured in figure 18.12, affect...

Q: Why is it more difficult to obtain evidence for trophic cascades in

Why is it more difficult to obtain evidence for trophic cascades in terrestrial ecosystems such as the Serengeti, compared to the lakes studied by Carpenter and Kitchell?

Q: What major conclusion can we draw from the pioneering experiment by Likens

What major conclusion can we draw from the pioneering experiment by Likens and Bormann?

Q: What do the results of Likens and Bormann and that of Turner

What do the results of Likens and Bormann and that of Turner and her colleagues suggest about the role of vegetation in preventing losses of nitrogen in forest ecosystems?

Q: Flood control on streams and rivers has often been cited as a

Flood control on streams and rivers has often been cited as a potential threat to populations of aquatic animals and riparian trees that require flooding for reproduction. How might flow regulation al...

Q: What causes community resilience?

What causes community resilience?

Q: How might taxonomic resolution—that is, how precisely we identify

How might taxonomic resolution—that is, how precisely we identify organisms—influence an assessment of community stability?

Q: Why should history have such a strong influence on regional diversity patterns

Why should history have such a strong influence on regional diversity patterns?

Q: How does the combined evidence from studies of the flora of Mediterranean

How does the combined evidence from studies of the flora of Mediterranean regions (fig. 22.22) and the diversity of trees in temperate forest regions increase confidence that h...

Q: Is the index of resilience used by Valett and his colleagues consistent

Is the index of resilience used by Valett and his colleagues consistent with the biomass accumulation model of Bormann and Likens?

Q: When we reviewed how some organisms use torpor, hibernation, and

When we reviewed how some organisms use torpor, hibernation, and estivation to avoid extreme temperatures, we discussed the idea of energy savings. However, organisms do not always behave in a way tha...

Q: Can a trait with no heritability, h2= 0, evolve

Can a trait with no heritability, h2= 0, evolve? Explain your answer.

Q: What does the effect of legumes on primary production in the Tilman

What does the effect of legumes on primary production in the Tilman experiment suggest about other factors limiting production on the experimental plots?

Q: If plant species richness and functional group composition accounted for one third

If plant species richness and functional group composition accounted for one third to two thirds of variation in primary production across study plots, what other f actors likely accounted for the rem...

Q: The Great Plains of North America once supported bison herds numbering in

The Great Plains of North America once supported bison herds numbering in the tens of millions. How did the near extermination of the bison likely affect nutrient cycling on the Great Plains?

Q: How might nitrogen and phosphorus composition and excretion ratios differ for invertebrate

How might nitrogen and phosphorus composition and excretion ratios differ for invertebrate consumers compared to vertebrate consumers?

Q: Why might restoration of native plant communities to their original structure be

Why might restoration of native plant communities to their original structure be difficult after exotic plants such as Myrica, in Hawaii, have occupied a site for a significant length of time?...

Q: What is the role of disturbance in the Connell and Slatyer succession

What is the role of disturbance in the Connell and Slatyer succession model (see fig. 20.20)? Figure 20.20:

Q: Suppose Gigartina had colonized the plots where Sousa had removed Ulva and

Suppose Gigartina had colonized the plots where Sousa had removed Ulva and where he had left Ulva in place at the same rates (see fig. 20.21). This result would be consistent with which su...

Q: What pattern of colonization by Gigartina in Sousa’s Ulva removal experiment would

What pattern of colonization by Gigartina in Sousa’s Ulva removal experiment would have been consistent with the facilitation model?

Q: How are “landscape engineers” similar to keystone species? How

How are “landscape engineers” similar to keystone species? How are they different?

Q: The section on avoiding temperature extremes focused mainly on animals. What

The section on avoiding temperature extremes focused mainly on animals. What are some of the ways in which plants avoid temperature extremes? Bring cold and hot environments into your discussion. Some...

Q: Can a dominant species of tree in a forest or coral on

Can a dominant species of tree in a forest or coral on a coral reef (see fig. 17.17, p. 386) be an ecosystem engineer? Figure 17.17:

Q: Why is there no one factor that seems to explain latitudinal gradients

Why is there no one factor that seems to explain latitudinal gradients in species diversity?

Q: The patterns shown in figure 21.28 support Minnich’s hypothesis that

The patterns shown in figure 21.28 support Minnich’s hypothesis that fire protection in southern California would produce a difference in median burn area. However, do these results...

Q: Why do those regions, whether tropical, desert, or temperate

Why do those regions, whether tropical, desert, or temperate, that include high mountains tend to be the most biologically diverse?

Q: Why would the soils in tropical rain forests generally be depleted of

Why would the soils in tropical rain forests generally be depleted of their nutrients more rapidly compared to the nutrients in temperate forest soils?

Q: How are the influences of El Niño and La Niña related to

How are the influences of El Niño and La Niña related to the concepts of top-down versus bottom-up control of populations, communities, and ecosystems?

Q: How does the example of El Niño and the Great Salt Lake

How does the example of El Niño and the Great Salt Lake confound the concepts of top-down and bottom-up control?

Q: The example of El Niño and the Great Salt Lake might lead

The example of El Niño and the Great Salt Lake might lead us to what general conclusion concerning the concepts of top-down and bottom-up control?

Q: Can we be confident that differences in growth within P. glandulosa

Can we be confident that differences in growth within P. glandulosa clones grown at different elevations were not the result of genetic differences? Why?

Q: What would you expect to see in figure 4.4 if

What would you expect to see in figure 4.4 if alpine, mid-elevation, and lowland populations of P. glandulosa were not different genetically?

Q: Some plants and grasshoppers in hot environments have reflective body surfaces,

Some plants and grasshoppers in hot environments have reflective body surfaces, which make their radiative heat gain, H r, less than it would be otherwise. If you were to design a tiger beetle that co...

Q: What is a fundamental evolutionary implication of the large amounts of genetic

What is a fundamental evolutionary implication of the large amounts of genetic variation commonly documented in natural populations?

Q: What advantages might the warm microenvironments of Dryas flowers offer to the

What advantages might the warm microenvironments of Dryas flowers offer to the insects attracted to them?

Q: Why is evaporative cooling by various animal species so effective?

Why is evaporative cooling by various animal species so effective?

Q: Contrast the microclimates of the aboveground parts of desert plants to that

Contrast the microclimates of the aboveground parts of desert plants to that of their roots.

Q: Why are the two curves shown in figure 6.2 so

Why are the two curves shown in figure 6.2 so similar? Figure 6.2:

Q: Which has a higher free energy content, pure water or seawater

Which has a higher free energy content, pure water or seawater?

Q: Why are water potentials in nature generally negative?

Why are water potentials in nature generally negative?

Q: What environmental conditions favor plants with C 3 photosynthesis? Why?

What environmental conditions favor plants with C 3 photosynthesis? Why?

Q: How are C 4 and CAM photosynthesis similar? How are they

How are C 4 and CAM photosynthesis similar? How are they different?

Q: Why does the ongoing increase in atmospheric CO 2 (see chapter

Why does the ongoing increase in atmospheric CO 2 (see chapter 23, fig. 23.21) not give guaranteed advantage to C 3 plants over C 4 plants? Figure 23.21:

Q: In most of the examples discussed in chapter 5, we saw

In most of the examples discussed in chapter 5, we saw a close match between the characteristics of organisms and their environment. However, natural selection does not always produce an optimal, or e...

Q: Why did John Endler take great care to put the same colors

Why did John Endler take great care to put the same colors of gravel in the same proportions into all of his greenhouse ponds (see fig. 8.5)? Figure 8.5:

Q: In Endler’s field experiment (see fig. 8.6),

In Endler’s field experiment (see fig. 8.6), why did male colorfulness increase in the absence of effective predators and not just remain unchanged? Figure 8.6:

Q: How may a species respond to climate change?

How may a species respond to climate change?

Q: How might biological and physical aspects of the environment interact to influence

How might biological and physical aspects of the environment interact to influence a species’ geographic distribution?

Q: Why might a species, such as the Eurasian collared dove,

Why might a species, such as the Eurasian collared dove, be less threatened by rapid climate change than hemlock or maple trees?

Q: Ecologists who have used clear plastic sheets coated with adhesive to trap

Ecologists who have used clear plastic sheets coated with adhesive to trap the adults of aquatic insects flying over rivers have found that the side of the sheets facing downstream generally traps mor...

Q: What do female guppies potentially gain by mating with colorful males?

What do female guppies potentially gain by mating with colorful males?

Q: What was the major assumption underlying Bennett’s (1983) use of

What was the major assumption underlying Bennett’s (1983) use of pollen deposited in lake sediments to estimate the postglacial population size of Scots pine?

Q: Why do many populations of exotic species, such as zebra mussels

Why do many populations of exotic species, such as zebra mussels in the Great Lakes (see fig. 3.41b) or Eurasian collared doves in Europe, often grow at exponential rates for some time following their...

Q: African annual killifish live in temporary pools, where their populations survive

African annual killifish live in temporary pools, where their populations survive the dry season as eggs that lie dormant in the mud, developing and hatching only when the pools fill each wet season....

Q: What changes in sea surface temperatures and atmospheric pressures over the Pacific

What changes in sea surface temperatures and atmospheric pressures over the Pacific Ocean accompany El Niño? What physical changes accompany La Niña? How do El Niño and La Niña affect precipitation in...

Q: The body temperature of the seashore isopod Ligia oceanica is 30 8

The body temperature of the seashore isopod Ligia oceanica is 30 8 C under stones, where the relative humidity is 100%, but 26 8 C on the surface, where it is exposed to full sun and the relative humi...

Q: Why did Westoby, Leishman, and Lord (1996) include

Why did Westoby, Leishman, and Lord (1996) include five floras on three continents in their study?

Q: Why did Jakobsson and Eriksson (2000) conduct their study of

Why did Jakobsson and Eriksson (2000) conduct their study of the relationship between seed size and seedling size in a greenhouse?

Q: Do you think that Grosholz might have observed food limitation if he

Do you think that Grosholz might have observed food limitation if he had used higher densities of Porcellio scaber in his experiments?

Q: How might using other indicators of competition, such as growth rate

How might using other indicators of competition, such as growth rate, reproductive rate, and size at maturity, have affected Grosholz’s conclusions regarding lack of food limitation in his study popul...

Q: Why did Moore conduct “blind” behavioral observations— that is

Why did Moore conduct “blind” behavioral observations— that is, without knowing whether individual Armadillidium was infected or not?

Q: How did Moore’s laboratory and field experiments complement each other?

How did Moore’s laboratory and field experiments complement each other?

Q: Large darter species produce larger numbers of smaller eggs compared to smaller

Large darter species produce larger numbers of smaller eggs compared to smaller darter species (see figs. 12.3 and 12.4). Consequently, would you expect to find more genetic differences along the leng...

Q: Why did Johnson create her inocula by mixing sterilized and unsterilized soils

Why did Johnson create her inocula by mixing sterilized and unsterilized soils from the fertilized and unfertilized study areas?

Q: Why did Johnson’s control consist of a sterilized mixture of soils from

Why did Johnson’s control consist of a sterilized mixture of soils from the fertilized and unfertilized study areas?

Q: Why do smaller samples result in only part of the bellshaped curve

Why do smaller samples result in only part of the bellshaped curve that is characteristic of the lognormal distribution?

Q: Distinguish among vapor pressure deficit, osmotic pressure, and water potential

Distinguish among vapor pressure deficit, osmotic pressure, and water potential. How can all three phenomena be expressed in the same units of measure: pascals?

Q: Why did the massive sampling efforts associated with the moth collections shown

Why did the massive sampling efforts associated with the moth collections shown in figure 16.4 reveal only a portion of the lognormal distribution, while the studies of birds and plants pr...

Q: In Inouye and Taylor’s study, why wasn’t the comparison of seed

In Inouye and Taylor’s study, why wasn’t the comparison of seed predation on plants naturally with and without ants sufficient to demonstrate the influence of ants on rates of seed predation?

Q: What are the main advantages of including only strong linkages in a

What are the main advantages of including only strong linkages in a food web?

Q: What was the primary way by which Tscharntke simplified the food web

What was the primary way by which Tscharntke simplified the food web representing the interactions of blue tits and feeding on insects living on the wetland reed Phragmites australis (see fig.Â&...

Q: In what other main way did Tscharntke simplify his study of trophic

In what other main way did Tscharntke simplify his study of trophic interactions in the wetland along the Elbe River?

Q: Why was precipitation alone, without temperature, sufficient to account for

Why was precipitation alone, without temperature, sufficient to account for most of the variation in grassland net primary production across central North America (see fig. 18.3)? Figure...

Q: How are the desert dune ecosystem and the arctic and alpine tundra

How are the desert dune ecosystem and the arctic and alpine tundra ecosystems indicated in figure 18.2 the same? Figure 18.2:

Q: How would actual evapotranspiration and net primary production in the desert dune

How would actual evapotranspiration and net primary production in the desert dune ecosystem, which is a hot desert, and the arctic and alpine tundra ecosystems likely respond to a significant increase...

Q: Do the oceans act as a source or a sink for phosphorus

Do the oceans act as a source or a sink for phosphorus (refer to fig. 19.2)? Figure 19.2:

Q: What are the relative fluxes of nitrogen through fixation and denitrification on

What are the relative fluxes of nitrogen through fixation and denitrification on land and in the oceans (see fig. 19.3)? Figure 19.3:

Q: Leaf water potential is typically highest just before dawn and then decreases

Leaf water potential is typically highest just before dawn and then decreases progressively through midday. Should lower leaf water potentials at midday increase or decrease the rate of water movement...

Q: Why do primary forest succession at Glacier Bay and secondary forest succession

Why do primary forest succession at Glacier Bay and secondary forest succession in the Southeastern United States occur at such different rates (compare figs. 20.2 and 20.4)? FigureÂ...

Q: In the landscapes shown in figure 21.4, what is

In the landscapes shown in figure 21.4, what is patch and what is matrix? Figure 21.4:

Q: What are the primary mechanisms producing the great differences in succession rates

What are the primary mechanisms producing the great differences in succession rates in forests, rocky intertidal, and stream communities?

Q: In chapter 21 we discussed the influences of habitat fragmentation from the

In chapter 21 we discussed the influences of habitat fragmentation from the perspective of populations (see figs. 21.11 and 21.12). Drawing from the information in this section, how do you think fragm...

Q: In figure 22.7, the number of mammal species on

In figure 22.7, the number of mammal species on the isolated mountain ranges varies greatly for a given distance from large montane areas, for instance, at a distance of 150 km. What is th...

Q: What are two ways in which the cutting of tropical forests and

What are two ways in which the cutting of tropical forests and replacing them with lower productivity cattle pastures affect the global carbon balance?

Q: How will global warming affect the proportion of the earth’s water that

How will global warming affect the proportion of the earth’s water that resides in the oceans?

Q: Why are virtually all estimates of immigration and extinction rates on islands

Why are virtually all estimates of immigration and extinction rates on islands underestimates of the true rates?

Q: What result would have been grounds for Diamond to reject the equilibrium

What result would have been grounds for Diamond to reject the equilibrium model of island biogeography based on his studies of the California Channel Islands (see fig. 22.10)? Figure&Acir...

Q: In the course of studies by Simberloff and Wilson (1969)

In the course of studies by Simberloff and Wilson (1969) and Simberloff (1976), several mangrove islands were defaunated and several were partially destroyed to reduce island area. Do such experiments...

Q: Compare the water budgets of the tenebrionid beetle, Onymacris, and

Compare the water budgets of the tenebrionid beetle, Onymacris, and the kangaroo rat, Dipodomys, shown in figures 6.9 and 6.10. Which of these two species obtains most of its water from me...

Q: Why is genetic drift more probable in small populations than in large

Why is genetic drift more probable in small populations than in large populations?

Q: How does highly selective mating by females (for example, see

How does highly selective mating by females (for example, see fig. 8.10) affect the potential for Hardy-Weinberg equilibrium? Figure 8.10:

Q: If growing lines of Escherichia coli at 20 8 C for 2

If growing lines of Escherichia coli at 20 8 C for 2,000 generations increased their fitness at 20 8 C without reducing their fitness at 40 8 C, how would the distribution of points in figureÂ&n...

Q: If your research team obtained the hypothetical results described in question 1

If your research team obtained the hypothetical results described in question 1, what could you conclude about the principle of allocation?

Q: How might immigration oppose the effects of genetic drift on genetic diversity

How might immigration oppose the effects of genetic drift on genetic diversity in a small population?

Q: The tiger beetle Cicindela oregona (see figs. 6.15

The tiger beetle Cicindela oregona (see figs. 6.15 and 6.16) has a distribution that extends from Arizona through the temperate rain forests of Alaska. Why should the amounts of cuticular...

Q: In general, what must be true of the chemical energy of

In general, what must be true of the chemical energy of the products of chemosynthesis compared to that of the reactants, for instance, the chemical energy of the product S0 (elemental sulfur) versus...

Q: During severe droughts, some of the branches of shrubs and trees

During severe droughts, some of the branches of shrubs and trees die, while others survive. How might losing some branches increase the probability that an individual plant will survive a drought?

Q: How are water and temperature regulation related in many terrestrial organisms?

How are water and temperature regulation related in many terrestrial organisms?

Q: What evidence is there that the availability of dead insects for scorpionfly

What evidence is there that the availability of dead insects for scorpionfly feeding is limited in nature?

Q: In this chapter, we discussed water relations of tenebrionid beetles from

In this chapter, we discussed water relations of tenebrionid beetles from the Namib Desert. However, members of this family also occur in moist temperate environments. How should water loss rates vary...

Q: What led Thornhill to conclude that mating success by male scorpionflies is

What led Thornhill to conclude that mating success by male scorpionflies is tied to the quality of nuptial offerings presented by males?

Q: Which results clearly show the influence of intrasexual selection on male scorpionfly

Which results clearly show the influence of intrasexual selection on male scorpionfly mating success?

Q: Are the concepts of “small” versus “large” scale

Are the concepts of “small” versus “large” scale the same for all organisms?

Q: How could you test the hypothesis that low overlap in root systems

How could you test the hypothesis that low overlap in root systems in creosote bush populations (see fig. 9.14) is the result of ongoing competition? Figure 9.14:

Q: In the study of the distribution of stingless bee colonies (see

In the study of the distribution of stingless bee colonies (see pp. 205–206), why were measurements of the number and distribution of potential nest trees necessary?

Q: Figure 10.11 and the upper portion of figure 21.

Figure 10.11 and the upper portion of figure 21.13 show the relationship between meadow size and population size in two butterfly species. How are the patterns shown by the two...

Q: The Rocky Mountain Parnassian butterfly tends to disperse from small to large

The Rocky Mountain Parnassian butterfly tends to disperse from small to large meadows. Why is this direction of movement more advantageous than the reverse?

Q: Contrast human influences on metapopulations of the Rocky Mountain Parnassian butterfly versus

Contrast human influences on metapopulations of the Rocky Mountain Parnassian butterfly versus those of the lesser kestrels of the Ebro River valley.

Q: Interpret the pattern of population growth shown by figure 11.11

Interpret the pattern of population growth shown by figure 11.11 in terms of the information given in figure 11.14, and discuss the relationship between population size and r (...

Q: How could you test the hypothesis that carrying capacity for the Paramecium

How could you test the hypothesis that carrying capacity for the Paramecium population shown in figure 11.10 was set by the availability of their main food—yeast cells?...

Q: In the Sonoran Desert, the only insects known to evaporatively cool

In the Sonoran Desert, the only insects known to evaporatively cool are cicadas. Explain how cicadas can employ evaporative cooling while hundreds of other insect species in the same environment canno...

Q: Why might a manager of an exploited population, such as a

Why might a manager of an exploited population, such as a commercially important fish, want to keep fish population size near one-half K and not much lower?

Q: What do the GSI values for rougheye rockfish, 0.02

What do the GSI values for rougheye rockfish, 0.02, and northern anchovy, 0.65, mean in terms of the body weights of these two fish species?

Q: What is a main difference between the study by Bertschy and Fox

What is a main difference between the study by Bertschy and Fox (1999) and that of Gunderson (1997)?

Q: The competitive exclusion principle states that two species cannot occupy the same

The competitive exclusion principle states that two species cannot occupy the same niche indefinitely. What is a fundamental assumption of this principle?

Q: Do resources have to be present in limited supplies for competition to

Do resources have to be present in limited supplies for competition to shape species niches?

Q: The patterns shown in figure 14.7 suggest that Helicopsyche depletes

The patterns shown in figure 14.7 suggest that Helicopsyche depletes its algal food supply. However, Lamberti and Resh were not certain and so conducted their second set of experiments. Wh...

Q: How could you test experimentally for the combined influence of bats and

How could you test experimentally for the combined influence of bats and birds on numbers of arthropods on foliage, as well as their individual contributions?

Q: If reef-building corals are placed in the dark, they

If reef-building corals are placed in the dark, they will expel the zooxanthellae in their tissues. What does this suggest concerning controls on the relationship between corals and zooxanthellae?

Q: In terms of costs and benefits, why might corals expel their

In terms of costs and benefits, why might corals expel their zooxanthellae when placed in the dark?

Q: Pollution of streams generally reduces the diversity of Trichoptera (see fig

Pollution of streams generally reduces the diversity of Trichoptera (see fig. 16.7), and several other groups of stream insects, by reducing both species richness and species e...

Q: Many desert species are well waterproofed. Evolution cannot, however,

Many desert species are well waterproofed. Evolution cannot, however, eliminate all evaporative water loss. Why not? (Hint: Think of the kinds of exchanges that an organism must maintain with its env...

Q: Suppose you sample an area and find the five species of forest

Suppose you sample an area and find the five species of forest trees listed in table 16.1 in the following proportions: 0.35, 0.25, 0.15, 0.15, and 0.10. What is the S hannon-Wiener divers...

Q: Why did Bertschy and Fox restrict their study to lakes without major

Why did Bertschy and Fox restrict their study to lakes without major inflows or outflows?

Q: How are competition and apparent competition the same?

How are competition and apparent competition the same?

Q: What distinguishes competition and apparent competition?

What distinguishes competition and apparent competition?

Q: Suppose that when you add nitrogen to one-half of a

Suppose that when you add nitrogen to one-half of a lake, you observe no change in phytoplankton biomass, but when you add phosphorus to the other half of the lake, phytoplankton biomass more than dou...

Q: How would the results of the experiment shown in figure 17.

How would the results of the experiment shown in figure 17.7 change if the effect of Brassica nigra on Nassella pulchra were the result of direct competition, with small herbivorous mamm...

Q: During the past 30 years, thousands of papers have been published

During the past 30 years, thousands of papers have been published on decomposition within ecosystems. Why have ecologists spent so much time studying decomposition?

Q: Suppose you fertilize a lake with nitrogen only, phosphorus only,

Suppose you fertilize a lake with nitrogen only, phosphorus only, and nitrogen plus phosphorus and observe no change in phytoplankton biomass. What is the most likely explanation of your results?...

Q: How are the results of Suberkropp and Chauvet (see fig. 

How are the results of Suberkropp and Chauvet (see fig. 19.12) and Rosemond (see fig. 19.13) similar? How do their results differ? Figure 19.12: Figure&Aci...

Q: Why are the changes in soil properties during the course of succession

Why are the changes in soil properties during the course of succession documented by Stuart Chapin and his colleagues ecologically significant?

Q: While we have concentrated in chapter 6 on regulation of water and

While we have concentrated in chapter 6 on regulation of water and salts, most marine invertebrates are isosmotic with their external environment. What is a potential benefit of being isosmotic?

Q: What would equal levels of nitrogen input and output in the stream

What would equal levels of nitrogen input and output in the stream reaches (sections) studied by Nancy Grimm indicate?

Q: How are the biomass accumulation model of Bormann and Likens (see

How are the biomass accumulation model of Bormann and Likens (see fig. 20.16) and Grimm’s observations of changes in nitrogen retention during succession in Sycamore Cree...

Q: What do the patterns shown in figure 21.11 suggest about

What do the patterns shown in figure 21.11 suggest about the relative impact of fragmentation of prairie habitat on populations of Sigmodon, Microtus, and Peromyscus Figure 21.11:

Q: Habitat corridors are widely recommended for conservation of species whose populations are

Habitat corridors are widely recommended for conservation of species whose populations are restricted to isolated patches of habitat. Why?

Q: Are there any potential risks associated with increasing the exchange of individuals

Are there any potential risks associated with increasing the exchange of individuals between habitat patches through the creation of habitat corridors?

Q: After years of successful reductions in phytoplankton populations, phytoplankton blooms are

After years of successful reductions in phytoplankton populations, phytoplankton blooms are on the increase in parts of Lake Erie following the introduction of zebra mussels. Why?

Q: Why is the prospect of global warming considered a serious threat to

Why is the prospect of global warming considered a serious threat to coral reefs?

Q: Why do physiologically tolerant rather than sensitive species inhabit estuaries and salt

Why do physiologically tolerant rather than sensitive species inhabit estuaries and salt marshes?

Q: The organic horizon is generally absent from agricultural soils because tilling,

The organic horizon is generally absent from agricultural soils because tilling, e.g., plowing, buries organic matter. Why is an organic horizon generally absent from desert soils?

Q: How does the construction of dams for storing water affect the turnover

How does the construction of dams for storing water affect the turnover time for water in rivers?

Q: Review water and salt regulation by marine and fresh water bony fish

Review water and salt regulation by marine and fresh water bony fish. Which of the two is hypoosmotic relative to its environment? Which of the two is hyperosmotic relative to its environment? Some sh...

Q: How would seasonality in temperature and precipitation be affected if earth’s rotation

How would seasonality in temperature and precipitation be affected if earth’s rotation on its axis were perpendicular to its plane of orbit about the sun?

Q: Why does the annual rainy season in regions near 23 8 N

Why does the annual rainy season in regions near 23 8 N latitude begin in June?

Q: Why is reducing forest area through deforestation a fundamental threat to biodiversity

Why is reducing forest area through deforestation a fundamental threat to biodiversity?

Q: What major pattern do patterns of island diversity and continental diversity have

What major pattern do patterns of island diversity and continental diversity have in common?

Q: Why is the ecological impact of deforestation always greater than the area

Why is the ecological impact of deforestation always greater than the area of forest removed?

Q: Why does grazing by Littorina on emergent substrata reduce algal diversity?

Why does grazing by Littorina on emergent substrata reduce algal diversity?

Q: Signs of thermal stress in fish include swimming on their sides and

Signs of thermal stress in fish include swimming on their sides and swimming in spirals. Using what you know about temperature and acetylcholinesterase, explain.

Q: How can we be sure that the two distinctive responses to temperature

How can we be sure that the two distinctive responses to temperature shown by Atriplex lentiformis were due to acclimation and not the result of genetic differences (see fig. 5.12)? Figu...

Q: Why do isosmotic marine invertebrates expend less energy for osmoregulation compared to

Why do isosmotic marine invertebrates expend less energy for osmoregulation compared to hypo osmotic marine fish?

Q: The body fluids of many freshwater invertebrate species have very low internal

The body fluids of many freshwater invertebrate species have very low internal salt concentrations. What is the benefit of such dilute internal fluids?

Q: Ronald Neilson and his colleagues (1992, 1995) used the

Ronald Neilson and his colleagues (1992, 1995) used the environmental requirements of plants to predict the responses of vegetation to climate change. In chapter 1, we briefly discussed the studies of...

Q: If you observe no changes in gene frequencies in a population over

If you observe no changes in gene frequencies in a population over several generations, can you conclude that the population is not subject to natural selection?

Q: Why do pumas face fewer challenges from the perspective of stoichiometry compared

Why do pumas face fewer challenges from the perspective of stoichiometry compared to herbivores, such as deer, on which they prey?

Q: Compare the dietary challenges associated with being a detritivore versus an herbivore

Compare the dietary challenges associated with being a detritivore versus an herbivore. Consider figure 7.14, p. 160. Figure 7.14:

Q: What roles did greenhouse and field studies play in the investigation of

What roles did greenhouse and field studies play in the investigation of mating patterns by wild radish?

Q: What would you expect to see in figure 8.15 if

What would you expect to see in figure 8.15 if performance were equal across pollen donors?

Q: Explain how a Batesian mimic, such as the hoverfly in figure 

Explain how a Batesian mimic, such as the hoverfly in figure 7.15 b, could evolve, through natural selection, from a nonaposematic ancestor. Figure 7.15b:

Q: What factors might be responsible for the aggregation of American crows in

What factors might be responsible for the aggregation of American crows in winter (see fig. 9.15)? Figure 9.15:

Q: Why might the winter aggregations of crows occur mainly along river valleys

Why might the winter aggregations of crows occur mainly along river valleys?

Q: What does the position of pines along moisture gradients in both the

What does the position of pines along moisture gradients in both the Santa Catalina Mountains of Arizona (see fig. 9.17) and the Great Smoky Mountains of Tennessee (see fig. 9....

Q: How would substantial emigration and immigration affect estimates of survivorship within a

How would substantial emigration and immigration affect estimates of survivorship within a population, where estimates are based on age distributions?

Q: Review evidence that the El Niño Southern Oscillation significantly influences populations around

Review evidence that the El Niño Southern Oscillation significantly influences populations around the globe. Much of our discussion in chapter 23 focused on the effects of the El Niño Southern Oscilla...

Q: Why don’t plants use highly energetic ultraviolet light for photosynthesis? Would

Why don’t plants use highly energetic ultraviolet light for photosynthesis? Would it be impossible to evolve a photosynthetic system that uses ultraviolet light? Does the fact that many insects see ul...

Q: Female cottonwood trees (Populus species) produce millions of seeds each

Female cottonwood trees (Populus species) produce millions of seeds each year. Does this information give you a sound basis for predicting their survivorship pattern?

Q: How would human mortality patterns have to change for our species to

How would human mortality patterns have to change for our species to shift from type I to type II survivorship?

Q: Why can we be sure that all animal and plant populations are

Why can we be sure that all animal and plant populations are under some form of environmental control?

Q: What appears to set the carrying capacity for medium ground finches on

What appears to set the carrying capacity for medium ground finches on Daphne Major Island?

Q: If a concept, such as r and K selection, does

If a concept, such as r and K selection, does not fully represent the richness of life history variation among species, can it still be valuable to science?

Q: Where would you place the following plant species, in Grime’s and

Where would you place the following plant species, in Grime’s and in Winemiller and Rose’s classifications of life histories (see figs. 12.20 and 12.21)? The plant...

Q: Why might medium ground finch population responses to short-term,

Why might medium ground finch population responses to short-term, episodic increases in rainfall (see fig. 11.17) differ from their responses to increases in rainfall lasting for years or...

Q: Paramecium aurelia and P. caudatum coexisted for a long period when

Paramecium aurelia and P. caudatum coexisted for a long period when fed full-strength food compared to when they were fed half that amount. What does this contrast in the time to competitive exclusion...

Q: Can we conclude that interspecific competition commonly restricts species to realized niches

Can we conclude that interspecific competition commonly restricts species to realized niches in nature, based on the results of mathematical models and laboratory experiments?

Q: Is there any way that predators could alter the outcome of competition

Is there any way that predators could alter the outcome of competition as shown in figure 13.14 a, where species 1 excludes species 2, and in figure 13.14 b, where species 2 ex...

Q: In what kinds of environments would you expect to find the greatest

In what kinds of environments would you expect to find the greatest predominance of C 3 , C 4 , or CAM plants? How can you explain the co-occurrence of two, or even all three, of these types of plants...

Q: When the coupled cycling of lynx and snowshoe hare populations (see

When the coupled cycling of lynx and snowshoe hare populations (see fig. 14.14) was first described, many concluded that lynx control snowshoe hare populations. Why are lynx not the primar...

Q: Why is it not surprising that snowshoe hare populations are controlled by

Why is it not surprising that snowshoe hare populations are controlled by a combination of factors, food and predators (see fig. 14.15), and not by a single environmental factor? Figure...

Q: Suppose you discover a mutant form of Helianthella quinquenervis that does not

Suppose you discover a mutant form of Helianthella quinquenervis that does not produce extrafloral nectaries. What does Keller’s theory predict concerning the relative fitness of these mutant plants a...

Q: According to Keller’s theory, under what general conditions would the mutant

According to Keller’s theory, under what general conditions would the mutant Helianthella quinquenervis, lacking extrafloral nectaries, increase in frequency in a population and displace the typical p...

Q: Both mathematical and laboratory models offer valuable insights into the dynamics of

Both mathematical and laboratory models offer valuable insights into the dynamics of predator-prey systems. What are some advantages and limitations of each approach?

Q: Does Tilman’s finding that Asterionella and Cyclotella exclude each other under certain

Does Tilman’s finding that Asterionella and Cyclotella exclude each other under certain conditions but coexist under other conditions violate the competitive e xclusion principle (see chapter 13, p. 2...

Q: Can we link increased nutrient availability during the Park Grass Experiment with

Can we link increased nutrient availability during the Park Grass Experiment with decreased environmental complexity?

Q: Suppose you discover that the fish species inhabiting small, isolated patches

Suppose you discover that the fish species inhabiting small, isolated patches of coral reef use different vertical zones on the reef face—some species live down near the sand, some live a bit higher o...

Q: Why is rapid, human-induced environmental change a threat to

Why is rapid, human-induced environmental change a threat to natural populations?

Q: Paine discovered that intertidal invertebrate communities of higher diversity include a higher

Paine discovered that intertidal invertebrate communities of higher diversity include a higher proportion of predator species. Did this pattern confirm Paine’s predation hypothesis?

Q: In chapter 7, we emphasized how the C 4 photosynthetic pathway

In chapter 7, we emphasized how the C 4 photosynthetic pathway saves water, but some researchers suggest that the greatest advantage of C 4 over C 3 plants occurs when CO2 concentrations are low. What...

Q: What was the major limitation of Paine’s first removal experiment involving Pisaster

What was the major limitation of Paine’s first removal experiment involving Pisaster?

Q: How can we explain the results of Lubchenco’s manipulation of Littorina populations

How can we explain the results of Lubchenco’s manipulation of Littorina populations summarized in figure 17.8? Figure 17.8:

Q: What component of species diversity (see chapter 16, p.

What component of species diversity (see chapter 16, p. 360) did Tilman’s research group manipulate in their studies? What other components of species diversity could influence rates...

Q: What can we conclude from the evidence summarized by figures 23.

What can we conclude from the evidence summarized by figures 23.20 to 23.23? Figures 23.20: Figures 23.23: Continue to next pages……â&...

Q: What aspects of global warming are widely supported by available evidence?

What aspects of global warming are widely supported by available evidence?

Q: Are there uncertainties remaining regarding global warming?

Are there uncertainties remaining regarding global warming?

Q: Why may the history of CFCs in the atmosphere in the years

Why may the history of CFCs in the atmosphere in the years following the Montreal Protocol offer encouragement as humanity strives to reverse the modern buildup of atmospheric CO 2?

Q: Why is rapid, human-induced environmental change a threat to

Why is rapid, human-induced environmental change a threat to natural populations?

Q: There is genetic evidence that mating between G. magnirostris and G

There is genetic evidence that mating between G. magnirostris and G. fortis (see fig. 13.8) may have helped establish sufficient genetic variation in the population of G. fortis at El Garrapatero for...

Q: Why would it be a disadvantage for Encelia farinose (p.

Why would it be a disadvantage for Encelia farinose (p. 110) to produce highly reflective, pubescent leaves in both hot and cool seasons?

Q: What are the relative advantages and disadvantages of being an herbivore,

What are the relative advantages and disadvantages of being an herbivore, a detritivore, or a carnivore? What kinds of organisms were left out of our discussions of herbivores, detritivores, and carni...

Q: Can behavioral thermoregulation be precise? What evidence supports your answer?

Can behavioral thermoregulation be precise? What evidence supports your answer?

Q: Why are all the endothermic fish relatively large?

Why are all the endothermic fish relatively large?

Q: In type 3 functional response, what mechanisms may be responsible for

In type 3 functional response, what mechanisms may be responsible for low rates of food intake—compared to type 1 and type 2 functional response—at low food densities?

Q: Why are plants such as mosses living in the understory of a

Why are plants such as mosses living in the understory of a dense forest, which show higher rates of photosynthesis at low irradiance, unable to live in environments where they are exposed to full sun...

Q: What conclusion can we draw from the parallel between photosynthetic response curves

What conclusion can we draw from the parallel between photosynthetic response curves in plants and functional response curves of animals?

Q: Throughout this series of discussions of investigating the evidence, we have

Throughout this series of discussions of investigating the evidence, we have emphasized one main source of evidence— original research. While original research is the foundation on w...

Q: In chapter 2 we calculated the sample mean and in chapter 3

In chapter 2 we calculated the sample mean and in chapter 3 we determined the sample median. The mean and median are different ways of representing the middle, or typical, within a sample of a populat...

Q: One of the most powerful ways to test a hypothesis is through

One of the most powerful ways to test a hypothesis is through an experiment. Experiments used by ecologists generally fall into one of two categories—field experiments and laboratory experiments. Fiel...

Q: The number of observations included in a sample, that is,

The number of observations included in a sample, that is, sample size, has an important influence on the level of confidence we place on conclusions based on that sample. Let’s exami...

Q: Ecologists are often interested in the relationship between two variables, which

Ecologists are often interested in the relationship between two variables, which we might call X and Y. For example, in chapter 7 we reviewed a study of how the size of pumas, variable X, is related t...

Q: What advantage does advertising give to noxious prey? How would convergence

What advantage does advertising give to noxious prey? How would convergence in aposematic coloration among several species of Müllerian mimics contribute to the fitness of individuals in each species?...

Q: As we have seen, the extent to which phenotypic variation in

As we have seen, the extent to which phenotypic variation in a trait is determined by genetic variation affects its potential to evolve by natural selection. In other words, the potential for a trait...

Q: Imagine sampling a population of plants or animals to determine the distribution

Imagine sampling a population of plants or animals to determine the distribution of individuals across the habitat. One of the most basic questions that you could ask is, “How are in...

Q: In chapter 1, we reviewed the roles of questions and hypotheses

In chapter 1, we reviewed the roles of questions and hypotheses in the process of science. Briefly, we considered how scientists use information to formulate questions about the natural world and conv...

Q: Ecologists often ask questions about observed frequencies of individuals in a population

Ecologists often ask questions about observed frequencies of individuals in a population relative to some theoretical or expected frequencies. For example, an ecologist studying the nesting habits of...

Q: Suppose you are studying the life history of three species of herbaceous

Suppose you are studying the life history of three species of herbaceous plants in a desert landscape. As part of that study, you are interested in determining the pattern of distribution of individua...

Q: Field experiments have played a key role in the assessment of the

Field experiments have played a key role in the assessment of the importance of competitive interactions in nature. Joseph Connell (1974) and Nelson Hairston, Sr. (1989), two of the pioneers in the us...

Q: When we introduced the sample mean, we pointed out how it

When we introduced the sample mean, we pointed out how it is an estimate of the actual, or true, population mean. A second sample from a population would probably have a different sample mean and a th...

Q: n chapter 14 we reviewed how to calculate the standard error,

n chapter 14 we reviewed how to calculate the standard error, s _ X, which is an estimate of variation among means of samples drawn from a population. Here, we will use the standard error to calculate...

Q: How many species are there? This is one of the most

How many species are there? This is one of the most fundamental questions that an ecologist can ask about a community. With increasing threats to biological diversity, species richness is also one of...

Q: In chapter 15 we reviewed how to calculate confidence intervals for the

In chapter 15 we reviewed how to calculate confidence intervals for the true population mean as: Here, we will use the confidence intervals calculated from samples of two populations to create a vis...

Q: Design a planetary ecosystem based entirely on chemosynthesis. You might choose

Design a planetary ecosystem based entirely on chemosynthesis. You might choose an undiscovered planet of some distant star or one of the planets in our own solar system, either today or at some dista...

Q: I n chapter 17, we used confidence intervals to compare the

I n chapter 17, we used confidence intervals to compare the biomasses of two populations of the diatom-feeding caddisfly, Neothremma alicia. That comparison indicated that the population living in a...

Q: In chapter 18 (p. 406) we compared samples from

In chapter 18 (p. 406) we compared samples from two populations using the t- test to judge whether there was a statistically significant difference between the populations. While the t -test is one of...

Q: The question we consider now is how to represent variation in samples

The question we consider now is how to represent variation in samples drawn from populations in which measurements or observations do not have normal distributions. When analyzing normally distributed...

Q: Suppose you are studying the exchange of organic matter between forests and

Suppose you are studying the exchange of organic matter between forests and streams and the landscape you are studying is a mosaic of patches of two forest types: deciduous and coniferous. Part of you...

Q: In chapter 6 (see p. 136) we considered the

In chapter 6 (see p. 136) we considered the number of samples necessary to obtain a reasonably precise estimate of the number of species in two simple communities. In chapter 16 (see p. 359) we recons...

Q: In chapter 2 (p. 18) we determined the sample

In chapter 2 (p. 18) we determined the sample mean. However, while the sample mean is one of the most common and useful of summary statistics, it is not the most appropriate statistic for some situati...

Q: One of the most common and important steps in the processing of

One of the most common and important steps in the processing of data is the production of summary statistics. First, what is a statistic? A statistic is a number that is used by scientists to estimate...

Q: Ecologists explore the relationships between organisms and environment using the methods of

Ecologists explore the relationships between organisms and environment using the methods of science. The series of boxes called “Investigating the Evidence” that ar...

Q: What kinds of animals would you expect to have type 1,

What kinds of animals would you expect to have type 1, 2, or 3 functional responses? How should natural selection for better prey defense affect the height of functional response curves? How should na...

Q: The rivers of central Portugal have been invaded, and densely populated

The rivers of central Portugal have been invaded, and densely populated by the Louisiana crayfish Procambarus clarki, which looks like a freshwater lobster about 12 to 14 cm long. The otters of these...

Q: The data of Iriarte and colleagues (1990) suggest that prey

The data of Iriarte and colleagues (1990) suggest that prey size may favor a particular body size among pumas (see fig. 7.19). However, this variation in body size also correlates well wit...

Q: The introduction to chapter 8 included sketches of the behavior and social

The introduction to chapter 8 included sketches of the behavior and social systems of several fish species. Using the concepts that you have learned in this chapter, revisit those examples and predict...

Q: In chapter 23, we briefly discussed how humans have more than

In chapter 23, we briefly discussed how humans have more than doubled the quantity of fixed nitrogen cycling through the biosphere. In chapter 15, we reviewed studies by Nancy Johnson (1993) on the ef...

Q: One of the basic assumptions of the material presented in chapter 8

One of the basic assumptions of the material presented in chapter 8 is that the form of reproduction will exert substantial influence on social interactions within a species. How might interactions di...

Q: Endler (1980) pointed out that though field observations are consistent

Endler (1980) pointed out that though field observations are consistent with the hypothesis that predators may exert natural selection on guppy coloration, some other factors in the environment could...

Q: Endler set up two experiments, one in the greenhouse and one

Endler set up two experiments, one in the greenhouse and one in the field. What were the advantages of the greenhouse experiments? What were the shortcomings of the greenhouse experiments? Endler also...

Q: Discuss the scorpionfly mating system. Pay particular attention to the potential

Discuss the scorpionfly mating system. Pay particular attention to the potential roles of intersexual and intrasexual selection in scorpionflies.

Q: The results of numerous studies indicate nonrandom mating among plants at least

The results of numerous studies indicate nonrandom mating among plants at least under some conditions. These results lead to questions concerning the biological mechanisms that produce these nonrandom...

Q: The details of experimental design are critical for determining the success or

The details of experimental design are critical for determining the success or failure of both field and laboratory experiments. Results often depend on some small details. For instance, why did Jenni...

Q: Behavioral ecologists have argued that naked mole rats are eusocial. What

Behavioral ecologists have argued that naked mole rats are eusocial. What are the major characteristics of eusociality and which of those characteristics are shared by naked mole rats?

Q: The oceans cover about 360 million km 2 and have an average

The oceans cover about 360 million km 2 and have an average depth of about 4,000 m. What proportion of this aquatic system receives sufficient light to support photosynthesis? Make the liberal assumpt...

Q: What confines Encelia farinosa to upland slopes in the Mojave Desert?

What confines Encelia farinosa to upland slopes in the Mojave Desert? Why is it uncommon along desert washes, where it would have access to much more water? What may allow E. frutescens to persist alo...

Q: Spruce trees, members of the genus Picea, occur throughout the

Spruce trees, members of the genus Picea, occur throughout the boreal forest and on mountains farther south. For example, spruce grow in the Rocky Mountains south from the heart of boreal forest all t...

Q: As we saw in chapters 18 and 19, nitrogen availability seems

As we saw in chapters 18 and 19, nitrogen availability seems to control the rates of several ecosystem processes. How should nitrogen enrichment affect rates of primary production and decomposition in...

Q: What kinds of interactions within an animal population lead to clumped distributions

What kinds of interactions within an animal population lead to clumped distributions? What kinds of interactions foster a regular distribution? What kinds of interactions would you expect to find with...

Q: How might the structure of the environment; for example, the

How might the structure of the environment; for example, the distributions of different soil types and soil moisture, affect the patterns of distribution in plant populations? How should interactions...

Q: Suppose one plant reproduces almost entirely from seeds, and that its

Suppose one plant reproduces almost entirely from seeds, and that its seeds are dispersed by wind, and a second plant reproduces asexually, mainly by budding from runners. How should these two differe...

Q: Suppose that in the near future, the fish crow population in

Suppose that in the near future, the fish crow population in North America declines because of habitat destruction. Now that you have reviewed the large-scale distribution and abundance of the fish cr...

Q: Use the empirical relationship between size and population density observed in the

Use the empirical relationship between size and population density observed in the studies by Damuth (1981) (see fig. 9.19) and Peters and Wassenberg (1983) (see fig.  9.20) to...

Q: Outline Rabinowitz’s classification (1981) of rarity, which she based

Outline Rabinowitz’s classification (1981) of rarity, which she based on size of geographic range, breadth of habitat tolerance, and population size. In her scheme, which combination of attributes mak...

Q: Can the analyses by Damuth (1981) and by Peters and

Can the analyses by Damuth (1981) and by Peters and Wassenberg (1983) be combined with that of Rabinowitz (1981) to make predictions about the relationship of animal size to its relative rarity? What...

Q: Outline Müller’s (1954, 1974) colonization cycle. If you

Outline Müller’s (1954, 1974) colonization cycle. If you were studying the colonization cycle of the freshwater snail Neritina latissima, how would you follow colonization waves upstream? How would yo...

Q: Compare cohort and static life tables. What are the main assumptions

Compare cohort and static life tables. What are the main assumptions of each? In what situations or for what organisms would it be practical to use either?

Q: Of the three survivorship curves, type III has been the least

Of the three survivorship curves, type III has been the least documented by empirical data. Why is that? What makes this pattern of survivorship difficult to study?

Q: Ecologists predict that global diversity is threatened by land use change and

Ecologists predict that global diversity is threatened by land use change and by the reductions in habitat area and the fragmentation that accompany land use change. Vitousek (1994) suggested that lan...

Q: Population ecologists have assumed that populations of species with very high reproductive

Population ecologists have assumed that populations of species with very high reproductive rates, those with offspring sometimes numbering in the millions per female, must have a type III survivorship...

Q: Draw hypothetical age structures for growing, declining, and stable populations

Draw hypothetical age structures for growing, declining, and stable populations. Explain how the age structure of a population with highly episodic reproduction might be misinterpreted as indicating p...

Q: Concept 10.5 says that we can use the information in

Concept 10.5 says that we can use the information in life tables and fecundity schedules to estimate some characteristics of populations (R0, T, r). Why does Concept 10.5 use the word “estimate” rathe...

Q: What values of R0 indicate that a population is growing, stable

What values of R0 indicate that a population is growing, stable, or declining? What values of r indicate a growing, stable, or declining population?

Q: From a life table and a fecundity schedule, you can estimate

From a life table and a fecundity schedule, you can estimate the geometric rate of increase, l, the average reproductive rate, R0 , the generation time, T, and the per capita rate of increase, r. That...

Q: C. S. Holling (1959) observed predator numerical responses

C. S. Holling (1959) observed predator numerical responses to changes in prey density. He attributed the numerical responses to changes in the reproductive rates of the predators. Discuss a hypothetic...

Q: For what types of organisms is the geometric model of population growth

For what types of organisms is the geometric model of population growth appropriate? For what types of organisms is the exponential model of population growth appropriate? In what circumstances would...

Q: While populations of gray and blue whales have grown rapidly, the

While populations of gray and blue whales have grown rapidly, the North Atlantic right whale population remains dangerously small despite many decades of complete protection. Assuming that differences...

Q: How do you build the logistic model for population growth from the

How do you build the logistic model for population growth from the exponential model? What part of the logistic growth equation produces the sigmoidal growth curve?

Q: In question 3, you thought about how the logistic growth equation

In question 3, you thought about how the logistic growth equation produces a sigmoidal growth curve. Now, let’s think about nature. What is it about the natural environment that produces sigmoidal gro...

Q: Skole and Tucker (1993) documented the rate and extent of

Skole and Tucker (1993) documented the rate and extent of recent deforestation in the Amazon Basin in Brazil. This is a prominent example of the land cover changes that likely threaten biological dive...

Q: What is the relationship between per capita rate of increase, r

What is the relationship between per capita rate of increase, r, and the intrinsic rate of increase, rmax? In chapter 10, we estimated r from the life tables and fecundity schedules of two species. Ho...

Q: Both abiotic and biotic factors influence birthrates and death rates in populations

Both abiotic and biotic factors influence birthrates and death rates in populations. Make a list of abiotic and biotic factors that are potentially important regulators of natural populations.

Q: Population biologists may refer to abiotic factors, such as temperature and

Population biologists may refer to abiotic factors, such as temperature and moisture, as density-independent because such factors can affect population processes independently of local population dens...

Q: Where on earth is human population density highest? Where is it

Where on earth is human population density highest? Where is it lowest? Where on earth do no people live? Where are human populations growing the fastest? Where are they approximately stable?

Q: What factors will determine the earth’s carrying capacity for Homo sapiens?

What factors will determine the earth’s carrying capacity for Homo sapiens? Explain why the earth’s long-term (thousands of years) carrying capacity for the human population may be much lower than the...

Q: The discussion of seed size and number focused mainly on the advantages

The discussion of seed size and number focused mainly on the advantages associated with large seeds. However, research by Westoby, Leishman, and Lord has revealed that the plants from widely separated...

Q: Under what conditions should natural selection favor production of many small offspring

Under what conditions should natural selection favor production of many small offspring versus the production of a few well provisioned offspring?

Q: Plant ecologists using experimental studies have verified that seedlings growing from larger

Plant ecologists using experimental studies have verified that seedlings growing from larger seeds have a better chance of surviving environmental challenges such as deep shade, drought, physical inju...

Q: The studies by Shine and Charnov (1992) and Gunderson (

The studies by Shine and Charnov (1992) and Gunderson (1997) addressed important questions of concern to life history ecologists and their work provided robust answers to those questions. However, the...

Q: Below about 600 to 1,000 m in the oceans there

Below about 600 to 1,000 m in the oceans there is no sunlight. However, many of the fish and invertebrates at these depths have eyes. In contrast, fish living in caves are often blind. What selective...

Q: Review the long-term atmospheric CO 2 record as revealed by

Review the long-term atmospheric CO 2 record as revealed by studies of air trapped in ice cores. What is the evidence that burning of fossil fuels is responsible for recent increases in atmospheric CO...

Q: Grime’s proposed classification of environments based on intensity of disturbance and stress

Grime’s proposed classification of environments based on intensity of disturbance and stress resulted in four environments, three of which he proposed were inhabitable by plants and one of which was n...

Q: Once established, Rio Grande cottonwoods can live to be well over

Once established, Rio Grande cottonwoods can live to be well over 100 years old. However, they experience very high rates of mortality as seeds, which only germinate in conditions that occur very unpr...

Q: Using what you know about the trade-off between seed number

Using what you know about the trade-off between seed number and seed size (e.g., fig. 12.7) and patterns of variation among plants, predict the relative number of seeds produced by the var...

Q: Apply Winemiller’s model to plants. If you were to construct a

Apply Winemiller’s model to plants. If you were to construct a strictly quantitative classification of plant life histories using Winemiller and Rose’s approach, wh...

Q: How is plant allocation to roots versus shoots similar to plant regulation

How is plant allocation to roots versus shoots similar to plant regulation of temperature and water? Consider discussing these processes under the more general heading of homeostasis. (Hint: Homeosta...

Q: Design a greenhouse (glasshouse) experiment to test for intraspecific competition

Design a greenhouse (glasshouse) experiment to test for intraspecific competition within a population of herbaceous plants. Specify the species of plant, the volume (or size of pot) and source of soil...

Q: How can the results of greenhouse experiments on competition help us understand

How can the results of greenhouse experiments on competition help us understand the importance of competition among natural populations? How can a researcher enhance the correspondence of results betw...

Q: Explain how self-thinning in field populations of plants can be

Explain how self-thinning in field populations of plants can be used to support the hypothesis that intraspecific competition a common occurrence among natural plant populations is.

Q: Researchers have characterized the niches of Darwin’s finches by beak size (

Researchers have characterized the niches of Darwin’s finches by beak size (which correlates with diet) and the niches of salt marsh grasses by position in the intertidal zone. How would you character...

Q: Explain why species that overlap a great deal in their fundamental niches

Explain why species that overlap a great deal in their fundamental niches have a high probability of competing. Now explain why species that overlap a great deal in their realized niches and live in t...