48. Ecology

An ecologist might conduct research to answer which of the following questions?

Why are many of the world's deserts located at latitudes between 30°N and 30°S?

When people speak of the rain shadow of the California Coast Range, what are they referring to?

Wet and dry seasons in tropical deciduous forests are ultimately caused by __________.

The warming of the Earth is a(n) __________ effect. People are worried that it will have a(n) __________ effect, perhaps causing the extinction of a number of species.

Which of the following statements about biomes is correct?

A climograph shows the mean temperature and precipitation values that support different biomes. What information is missing that would help predict what biome should be found in a particular range?

Different species that inhabit the same type of biome but occur in widely separated geographic regions often appear similar due to __________.

What helps produce the patchiness found in most biomes?

Permafrost is characteristic of the __________.

Which biome is the largest terrestrial biome on Earth?

Cattle egrets, originally only found in Africa and southwestern Europe, can now be found in North America because of which of the following?

Which of the following choices correctly pairs a terrestrial biome with some of its characteristics?

An immature frog (a tadpole) lives in a pond or lake. However, the adult frog possesses special adaptations that permit it to survive in a terrestrial environment. These special adaptations __________.

Which of the following biomes is dominated by gymnosperm or conifer trees (pines, firs, spruces)?

Of these biomes, vertical stratification (layers of plants) is most pronounced in the __________.

In a rather infamous case of species transplantation, starlings were introduced into North America from Europe in 1890 by an eccentric Shakespeare fan. Though the actual range of starlings was originally in the Eastern Hemisphere, it is clear that North America was part of its __________ range.

What is the importance of turnover in temperate lakes?

Temperature, precipitation, sunlight, and wind are the major components of __________

What could a climograph be used for?

Which statement is true about the tundra?

Below the photic zone of the ocean, __________.

Where do fringe wetlands develop?

Rooted plants are found only in which zone of a lake?

Which choice below describes a feature of grassland that explains why its remnants are concentrated in arid regions of North America and central Asia?

Which of the following is characteristic of oligotrophic lakes?

After nutrient enrichment from sewage contamination, a lake often becomes inhospitable to fish. Why?

Plankton consists of __________.

Which of the following pairs of biomes is characterized by relatively simple food webs (low biological diversity)?

Communities that exist in the aphotic zone ultimately depend on food manufactured by chemoautotrophic bacteria or __________.

In which of the following biomes would you expect decomposers to work most rapidly and efficiently?

Explain why the northern United States experiences a cold season in winter and a warm season in summer.

Which of the following areas of study focuses on the exchange of energy, organisms, and materials between ecosystems? a. organismal ecology b. landscape ecology c. ecosystem ecology d. community ecology

You have seen that Earth's terrestrial biomes reflect regional variations in climate. But what determines these climatic variations? Interpret the following diagrams in reference to how each represents effects on global patterns of temperature, rainfall, and winds. a. Solar radiation and latitude: b. Earth's orbit around the sun: c. Global patterns of air circulation and rainfall:

Name the five main levels of study in ecology from smallest to largest.

Which lake zone would be absent in a very shallow lake? a. benthic zone b. aphotic zone c. pelagic zone d. littoral zone

Match each description on the left with the correct biome on the right. 2. The most complex and diverse biome 3. Ground permanently frozen 4. Deciduous trees such as ­hickory and birch 5. Limited to small coastal areas 6. Spruce, fir, pine, and hemlock trees 7. Home of ants, antelopes, and lions 8. North American plains a. chaparral b. savanna c. taiga d. temperate broadleaf forest e. temperate grassland f. tropical rain forest g. arctic tundra

Where do rain shadows exist? a. the part of a mountain that receives prevailing winds and heavy rain b. the region beyond a mountain range that receives dry air c. the region along the equator where precipitation is abundant d. the region near 30°N and 30°S latitude that receives dry air

Add labels to the figure that follows, which illustrates how various factors influence local climate.

Which of the following is characteristic of most terrestrial biomes? a. a distribution predicted almost entirely by rock and soil patterns b. clear boundaries between adjacent biomes c. vegetation demonstrating vertical layering d. cold winter months

Which of the following groups is (are) absolutely essential to the functioning of an ecosystem? a. producers b. producers and herbivores c. producers, herbivores, and carnivores d. producers and decomposers

What is the main type of vegetation in a tropical wet forest? a. shrubs and bunchgrasses b. herbs, grasses, and vines c. broad-leaved deciduous trees d. broad-leaved evergreen trees

Areas of low solar irradiation are                   . a. closer to the equator than to the poles; b. closer to the poles than the equator; c. at high altitudes; d. close to large bodies of water; e. more than one of the above is correct

The oceans affect the biosphere by (A)absorbing a substantial amount of the biosphere's oxygen. (B)regulating the pH of freshwater biomes and terrestrial groundwater. (C)decreasing winter temperatures of coastal terrestrial biomes. (D)removing carbon dioxide from the atmosphere.

The oceans affect the biosphere in all of the following ways except a. producing a substantial amount of the biosphere's oxygen. b. removing carbon dioxide from the atmosphere. c. moderating the climate of terrestrial biomes. d. regulating the pH of freshwater biomes and terrestrial groundwater.

What is one expected consequence of global climate change? a. Average rainfall will increase. b. Average rainfall will decrease. c. Variability in rainfall will increase. d. We cannot make predictions about future rainfall.

The solar equator, the region of Earth where the sun is directly overhead, moves from 23.5°N to 23.5°S latitudes and back over the course of a year. Why? a. Earth wobbles on its axis during the year; b. The position of the poles changes by this amount annually; c. Earth's axis is 23.5° from perpendicular to the rays of the sun; d. Earth moves 23.5° toward the sun in summer and 23.5° away from the sun in winter; e. Ocean currents carry heat from the tropical ocean north in summer and south in winter

Which statement about dispersal is true? (A)Dispersal is not a component of the life cycles of most plants and animals. (B)Dispersal occurs only on an evolutionary time scale. (C)Colonization of devastated areas after floods or volcanic eruptions depends on dispersal. (D)The ability to disperse does not affect the geographic distribution of a species.

Which statement about dispersal is false? a. Dispersal is a common component of the life cycles of plants and animals. b. Colonization of devastated areas after floods or volcanic eruptions depends on dispersal. c. Dispersal occurs only on an evolutionary time scale. d. The ability to disperse can expand the geographic distribution of a species.

Which of these statements about aquatic biomes is true? Select True or False for each statement. T/F The ocean is so vast that it is not influenced by human impacts. T/F Water depth, water flow, salinity, and nutrient availability are important abiotic factors in aquatic biomes. T/F Once nutrients sink to the bottom of lakes, they are no longer available to organisms.

Which of the following biomes is most common on Earth's land surface? a. chaparral; b. desert; c. temperate forest; d. tundra; e. boreal forest

When climbing a mountain, we can observe transitions in biological communities that are analogous to the changes a. in biomes at different latitudes. b. in different depths in the ocean. c. in a community through different seasons. d. in an ecosystem as it evolves over time.

Explain how the open ocean is similar to the desert, and how it is not.

Tundra is found                   . a. where average temperatures are low and growing seasons are short; b. near the poles; c. at high altitudes; d. A and B are correct; e. A, B, and C are correct

Suppose that the number of bird species is determined mainly by the number of vertical strata found in the environment. If so, in which of the following biomes would you find the greatest number of bird species? a. tropical rain forest b. savanna c. desert d. temperate broadleaf forest

The open ocean and tropical rain forests contribute the most to Earth's net primary production because a. both have high rates of net primary production. b. both cover huge surface areas of Earth. c. nutrients cycle fastest in these two ecosystems. d. the ocean covers a huge surface area and the tropical rain forest has a high rate of production.

Temperate forest in China and temperate forest in North America are part of the same biome but are distinct ecosystems. Explain.

Which statement best describes the desert biome? a. It is found wherever temperatures are high; b. It contains a larger amount of biomass per unit area than any other biome; c. Its dominant vegetation is adapted to conserve water; d. Most are located at the equator; e. It is not suitable for human habitation

Compare the distribution of the natural terrestrial biomes of eastern North America with the distribution of anthropogenic biomes.

Which of the following biomes has a structure made up primarily of the mineral deposits secreted by its dominant organisms? a. coral reefs; b. freshwater lakes; c. rivers; d. estuaries; e. oceans

Changes in the seasons are caused by a. the tilt of Earth's axis toward or away from the sun. b. annual cycles of temperature and rainfall. c. variation in the distance between Earth and the sun. d. an annual cycle in the sun's energy output.

Like Earth, Mars has seasons—its Northern Hemisphere experiences winter when its Southern Hemisphere experiences summer. Which statement is the best explanation for seasonality on Mars? a. Mars is tilted on its axis. b. Mars has an elliptical orbit that brings it closer to the Sun in summer than in winter. c. Mars has a circular orbit and maintains a constant distance from the Sun. d. The Southern Hemisphere of Mars consistently receives direct solar radiation.

In an ecosystem, how is the flow of energy similar to that of matter, and how is it different?

What makes the Gobi Desert of Asia a desert? a. The growing season there is very short. b. It is hot. c. Temperatures vary little from summer to winter. d. It is dry.

Scientists predict that global climate change will cause a greater increase in average temperature at higher latitudes than in the tropics. This seems like good news since most of the world's biodiversity occurs in the tropics. However, recent data suggest that a smaller temperature change in the tropics will cause a larger physiological response in organisms there than the larger temperature change will in organisms in temperate areas. Based on what you have learned about thermal niches in this chapter, propose a hypothesis to explain this result.

Which of the following sea creatures might be described as a pelagic animal of the aphotic zone? a. a coral reef fish b. an intertidal snail c. a deep-sea squid d. a harbor seal

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. Why are species like the lionfish considered 'invasive'? a. They are found in areas where they are not native. b. They were accidentally introduced by humans. c. They spread aggressively and displace native species. d. They are predators of other fish.

Why do the tropics and the windward side of mountains receive more rainfall than areas around latitudes 30° north and south and the leeward side of mountains? a. Rising warm, moist air cools and drops its moisture as rain. b. Descending air condenses, creating clouds and rain. c. There is more solar radiation in the tropics and on the windward side of mountains. d. Earth's rotation creates seasonal differences in rainfall.

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. Lionfish are usually found in full-salinity seawater (35 parts per thousand). However, lab studies show that lionfish can tolerate salinities as low as 4 parts per thousand for several days, suggesting that the low-salinity water of estuaries (such as at the mouth of the Amazon River) may not be a barrier to lionfish dispersal along the coasts. Sketch a niche model predicting lionfish abundance as a function of salinity.

Phytoplankton are the major photosynthesizers in a. the benthic realm of the ocean. b. the ocean photic zone. c. the intertidal zone. d. the aphotic zone of a lake.

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. DNA studies suggest that the lionfish invasion began with just a few females released off the coast of Florida, probably from a fish tank. Based on your knowledge of ocean currents, predict the direction in which the lionfish dispersed most quickly.

An ecologist monitoring the number of gorillas in a wildlife ­refuge over a five-year period is studying ecology at which level? a. organism b. population c. community d. ecosystem

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. List the five main levels of ecological study, and write a question about the ecology of lionfish that you could research at each level.

Tropical rain forests are the most diverse biomes. What factors contribute to this diversity?

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. Biologists are scrambling to study the reproductive biology of lionfish to inform management decisions. For example, Alexander Fogg and colleagues studied lionfish females in the northern Gulf of Mexico and estimated that an average female could produce 2,332,490 eggs per year. What time of year is reproductive rate the highest? To answer this question, the researchers collected an average of 200 lionfish each month and measured ovary size relative to body size, an indicator of reproductive capacity. Describe the take-home message of the graph. How do the error bars affect your confidence in this message?

What biome do you live in? Describe your climate and the factors that have produced that climate. What plants and animals are typical of this biome? If you live in an urban or agricultural area, how have human interventions changed the natural biome?

The red lionfish, Pterois volitans, has beautiful red stripes, streaming fins, and a fearless disposition, and it is deadly. Native to the Pacific Ocean, the red lionfish was first discovered on coral reefs in the Bahamas in 1985. The species has spread to over 3 million square kilometers of the western Atlantic and Gulf of Mexico. Lionfish have a voracious appetite for native fish, are armed with venomous spines, and have no natural predators in their new range. Volunteer conservation organizations have hosted 'lionfish derbies' and lionfish cookouts to promote the capture of thousands of lionfish from reefs in Florida and the Bahamas. Conservationists are also trying to promote a fishery for these small but tasty fish. Give one reason that it would be easy to promote the consumption of lionfish. Describe one possible challenge to this effort.

In the climograph below, biomes are plotted by their range of annual mean temperature and annual mean precipitation. Identify the following biomes: arctic tundra, coniferous forest, desert, grassland, temperate forest, and tropical forest. Explain why there are areas in which biomes overlap on this graph.