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CHAPTER 7
CLIMATE AND BIODIVERSITY
Outline
D Concepts
7-1 What factors influence climate?
A. The earth has many different climates.
2. Climate is an area’s general pattern of atmospheric conditions over periods ranging from 30 to
thousands of years.
4. Climate varies in different parts of the earth primarily because global air circulation and ocean
5. Three major factors determine how air circulates in the lower atmosphere:
6. Prevailing winds blowing over the oceans produce mass movements of surface water called
7. El Niño–Southern Oscillation, or ENSO—is an example of the interaction of land and air.
a. Large-scale weather phenomenon occurring every few years when prevailing winds in
the tropical Pacific Ocean weaken and change direction.
b. Above-average warming of Pacific waters can affect populations of marine species by
changing the distribution of plant nutrients.
B. Greenhouse gases warm the lower atmosphere.
1. Greenhouse gases absorb and release heat, which warms the atmosphere, influencing the
earth’s average temperatures and its climates. The major greenhouse gases are:
2. The natural greenhouse effect is a warming of the lower atmosphere and the earth’s surface.
Some of the energy that the earth’s surface absorbs from the sun is radiated into the
atmosphere as heat. Greenhouse gases absorbed some of this heat which warms the lower
atmosphere, causing the greenhouse effect.
C. The earth’s surface features affect local climates.
1. Heat is absorbed and released more slowly by water than by land, creating land and sea
breezes.
3. High mountains create the rain shadow effect.
7-2 What are the world’s major terrestrial ecosystems and how are human activities affecting them?
A. Climate helps to determine where organisms can live.
1. Average annual precipitation and temperature lead to the formation of tropical (hot),
temperate (moderate), and polar (cold) deserts, grasslands, and forests.
3. Biomes are large regions, each characterized by certain types of climate and dominant plant
4. Biomes are not uniform. They consist of a mosaic of patches, each with somewhat different
biological communities but with similarities typical of the biome.
B. There are three major types of desert.
1. Deserts have low annual precipitation often scattered unevenly throughout the year. The sun
warms the ground during the day and evaporates water; heat is quickly lost at night.
3. Temperate deserts have high daytime temperatures in summer and low in winter. Sparse
vegetation is mostly cacti and other succulents.
5. Desert soils take from decades to centuries to recover from disturbances such as off-road
6. SCIENCE FOCUS: Staying alive in the desert
a. Adaptations for survival in the desert have two themes: beat the heat and every drop of
water counts.
b. In plants, leaves are designed to minimize water loss and root systems to maximize
water collection. Many plants have spines to avoid being eaten by herbivores seeking
the water they hold.
c. Most desert animals are small. Some are nocturnal and hiding in cool burrows during
the by day, others are dormant during periods of extreme heat or drought. Some larger
C. There are three major types of grasslands.
1. Grasslands occur mostly in the interiors of continents in areas too moist for deserts and too
dry for forests.
3. The three main types of grassland:
4. Temperate, e.g. short-grass and tall-grass prairies.
5. Cold, e.g. cold grasslands or arctic tundra.
a. Cold grasslands, or arctic tundra, are bitterly cold, treeless plains.
i. Permafrost forms when frozen underground soil exists for more than two
consecutive years.
b. Tundras usually have nutrient-poor soils.
i. Alpine tundra occurs above the limit of tree growth but below the
permanent snow line on high mountains.
D. There are three major types of forests.
1. Forests are lands dominated by trees.
2. The three main types of forest:
a. Tropical forests are found near the equator with a constant warm and wet climate, which
is ideal for a wide variety of plants and animals.
i. Dominated by broadleaf evergreen plants keep most of their leaves year-
Chapter 7: Climate and Biodiversity
b. Temperate.
c. Cold: northern coniferous (cone-bearing) and boreal.
i. Cool temperatures slow decomposition, so have a thick layer of slowly
decaying leaf litter which is a storehouse of nutrients
E. Mountains play important ecological roles.
2. About 1.2 billion people (17% of the world’s population) live in mountain ranges or their
3. Many mountains are islands of biodiversity surrounded by a sea of lower-elevation landscapes
transformed by human activities.
4. Important ecological roles include
a. Contain the majority of the world’s trees,
5. CONNECTIONS: Mountains and climate.
a. Mountains help regulate the earth’s climate, with the ice-covered tops reflecting the sun
7. Humans Have Disturbed Much of the Earth’s Land
7-3 What are the major types of marine aquatic systems and how are human activities affecting them?
1. About 71% of the earth’s surface is covered with salty ocean water.
2. One global ocean, divided it into four large areas by geographers.
a. Atlantic Ocean.
3. Aquatic life zones are the aquatic counterparts of biomes
4. Distribution of aquatic organisms is determined largely by the water’s salinity—the amounts
of various salts such as sodium chloride (NaCl) dissolved in a given volume of water.
5. Aquatic life zones are classified into two major types:
6. Four major types of aquatic organisms:
a. Plankton are weakly swimming and free-floating. Types include:
i. Phytoplankton: photosynthesizers, includes many types of algae.
ii. Zooplankton: plankton that feed on other plankton.
7. Key factors determining the type and number of organisms at various depths include:
a. Water temperature.
1. Enormous reservoirs of biodiversity with three major life zones, the coastal zone, open sea
and ocean bottom.
2. The coastal zone
a. Warm, nutrient-rich, shallow water that extends from the high-tide mark on land to the
edge of the continental shelf.
b. Makes up less than 10% of the world’s ocean area while containing 90% of all marine
species and is the site of most large commercial marine fisheries.
c. Have high net primary productivity due to ample sunlight and plant nutrients that flow
from land.
C. Estuaries and coastal wetlands are highly productive.
1. Estuaries are where rivers meet the sea, forming partially enclosed bodies of water where
2. Associated coastal wetlands are areas covered with water all or part of the year.
3. Some of the earth’s most productive ecosystems.
5. Coastal aquatic systems provide vital ecological and economic services such as:
a. Help to maintain water quality in tropical coastal zones by filtering toxic pollutants,
excess plant nutrients, and sediments, and by absorbing other pollutants.
b. Provide food, habitats, and nursery sites for a variety of aquatic and terrestrial species.
c. Reduce storm damage and coastal erosion by absorbing waves and storing excess water
produced by storms and tsunamis.
D. Coral reefs are storehouses of biodiversity.
1. Underwater structures that are built primarily of limestone and form in the clear, warm coastal
waters of the tropics and subtropics.
3. Reefs form from massive colonies of polyps that secrete limestone.
5. Ecological services provided by coral reefs include:
a. Act as natural barriers that help to protect 15% of the world’s coastlines from erosion
6. Coral reefs are easily damaged because they grow slowly, are disrupted easily and require
specific water conditions.
7. Coral bleaching occurs when stresses such as increased temperature cause the symbiotic
8. Ocean water is becoming more acidic as it absorbs some of excess carbon dioxide from the
9. Almost 45–53% of the world’s shallow coral reefs have been destroyed or degraded by
coastal development, pollution, overfishing, warmer ocean temperatures, increasing ocean
acidity, and other stresses.
E. The open sea and the ocean floor host a variety of species.
1. The open sea occurs beyond the edge of the continental shelf and is divided into three vertical
zones largely on the basis of the penetration of sunlight.
a. The euphotic zone is the brightly lit upper zone, where drifting phytoplankton carry out
F. Human activities are disrupting and degrading marine ecosystems.
G. About 45% of the world’s population and more than half of the U.S. population live along or near
coasts.
H. Major threats to marine systems from human activities include:
2. Runoff of nonpoint source pollution such as fertilizers, pesticides, and livestock.
4. Overfishing, which depletes populations of commercial fish species.
6. Invasive species, some introduced by humans, that can out compete populations of native
aquatic species and cause economic damage.
7. Climate change which is warming the oceans and making them more acidic; this could cause
7-4 What are the major types of freshwater systems and how are human activities affecting them?
A. Water stands in some freshwater systems and flows in others.
2. Lakes are large natural bodies of standing freshwater formed when precipitation, runoff,
streams and rivers, and groundwater seepage fill depressions.
4. Eutrophic (well-nourished) lakes have a large supply of nutrients needed by producers,
causing them have high productivity and look murky brown or green.
6. Freshwater streams and rivers carry water from the mountains to the oceans.
B. Surface water forms when precipitation does not sink into the ground or evaporate.
2. A watershed, or drainage basin, is the land area that delivers runoff, sediment, and dissolved
substances to a stream or lake.
3. The downward flow of surface water and groundwater from mountain highlands to the sea
typically takes place in three aquatic life zones characterized by different environmental
4. CONNECTIONS: Streams and bordering land
Instructor’s Manual for Environmental Science, 15th edition
a. Streams receive many of their nutrients from bordering land influencing these
ecosystems.
C. Freshwater inland wetlands are vital sponges.
1. Inland wetlands are lands covered with freshwater all or part of the time (excluding lakes,
reservoirs, and streams) and located away from coastal areas.
a. Marshes (dominated by grasses and reeds with few trees).
b. Swamps (dominated by trees and shrubs).
2. Inland wetlands provide a number of free ecological and economic services, which include:
a. Filtering and degrading toxic wastes and pollutants.
b. Reducing flooding and erosion by absorbing storm water and releasing it slowly, and by
absorbing overflows from streams and lakes,
c. Maintaining stream flows during dry periods,
D. Human activities are disrupting and degrading freshwater systems.
1. Dams and canals alter and destroy terrestrial and aquatic wildlife habitats along rivers and in
their coastal deltas and estuaries by reducing water flow and increasing damage from coastal
storms.
3. Cities and farms add pollutants and excess plant nutrients to nearby streams, rivers, and lakes.
4. Many inland wetlands have been drained or filled to grow crops or have been covered with
concrete, asphalt, and buildings.
6. This chapter’s three big ideas are:
a. Differences in climate, based mostly on long-term differences in average temperature
and precipitation, largely determine the types and locations of the earth’s deserts,
7-1 What factors influence climate?
CONCEPT 7-1 Key factors that influence an area’s climate are incoming solar energy, the earth’s rotation,
global patterns of air and water movement, gases in the atmosphere, and the earth’s surface features.
1. Distinguish between weather and climate.
3. Describe the causes and effects of ocean currents. Define El Niño and describe what causes it and what
affects it has on marine species.
5. Describe the general effects of the following microclimates: windward and leeward sides of a
mountain, forests, and cities.
7-2 What are the world’s major terrestrial ecosystems and how are human activities affecting them?
CONCEPT 7-2A Differences in long-term average annual precipitation and temperature lead to the formation of
tropical, temperate, and cold deserts, grasslands, and forests, and largely determine their locations.
CONCEPT 7-2B Human activities are disrupting ecosystem and economic services provided by many of the
earth’s deserts, grasslands, forests, and mountains.
1. Describe how climate affects the distribution of plant life on Earth. Draw connections between biomes
3. Compare the biodiversity and stratification in the three major kinds of forest.
7-3 What are the major types of marine aquatic systems and how are human activities affecting them?
CONCEPT 7-3 Oceans dominate the planet and provide vital ecosystem and economic services that are being
disrupted by human activities.
1. List four human impacts on each type of terrestrial ecosystems.
7-4 What are the major types of freshwater systems and how have human activities affected them?
CONCEPT 7-4 Freshwater lakes, rivers, and wetlands provide important ecological and economic services that
are being disrupted by human activities
2. Distinguish between marine and freshwater life zones and list several examples of each.
4. List four factors that determine the type and number of organisms found at various depths.
Key Terms
aquatic life zone
biome
climate
coastal wetland
coastal zone
estuary-
eutrophic lakes
freshwater life zone
greenhouse effect
greenhouse gas
open sea
permafrost
rain shadow effect
runoff
saltwater marine life zone
Teaching Tips
Because climate and weather are topics most are familiar with, begin by asking students to describe the
climate of places they have visited on vacation recently, and how that climate differed from where they
originate.
• Ask students to list the plant and animal species they saw while traveling. Use this to introduce the
notion that climate influences the terrestrial ecosystems of the world.
• Next, ask them how aquatic ecosystems might differ from their terrestrial counterparts.
• Lastly, use the provided information to discuss how human activity has impacted the ecosystems
they have traveled to.
Instructor’s Manual for Environmental Science, 15th edition
“Moving around” discussion:
• Ask your students to tell you what they would tell a friend/exchange student to bring for clothing
if that individual were coming to your school next year.
• Ask your students how they know what to pack when they take a trip.
Discussion Topics
1. What are several long- and short-term climate changes? What are the effects of changing climate on
the composition and distribution of ecosystems?
2. What are several of the plant and animal adaptations in different biomes: desert plants and animals;
plants and animals of the tundra; mountain microclimates and vertically zoned vegetation; organisms
of the Amazon?
3. How are deserts, tropical forests, and the tundra fragile ecosystems?
4. How do humans affect coral reefs? Should tourism to tropical islands be restricted? What regulations
on snorkeling and scuba diving would help protect coral reefs?
5. What is life like at hydrothermal vents in the deep ocean?
6. Should we retreat from the beach? Should houses built on barrier beaches have access to insurance?
7. What are your local wetland protection regulations and why do they exist?
8. How can beach erosion be prevented and should people interfere with this natural process?
9. What are several coastal cleanup strategies and how effective are they?
Activities and Projects
1. Ask students to bring to class and share examples of art, music, poetry, and other creative expressions
2. What significantly different microclimates exist in your locale? As a class project, inventory these
3. Are inland wetlands being drained and filled in your locale? Is there a nearby stream or river being
subjected to excessive levels of pollution? Are there ponds and lakes in your vicinity suffering from
cultural eutrophication? Do you live where marshes or estuaries are suffering from human-induced
4. Arrange a debate on the problems and alternatives of coastal zone management. Debate the
proposition that we should severely restrict engineering approaches to beach stabilization and adopt a
1. Do you feel that the development of your community is related to the climate of the area?
2. Are you aware of mountains or bodies of water in your area that affect local climate conditions?
3. Have you visited a variety of types of ecosystems? If so, where do you feel most at home?
Laboratory Skills
Wells, Edward. Lab Manual for Environmental Science. 2009. Lab #9: Butcher the Biome.
Wells, Edward. Lab Manual for Environmental Science. 2009. Lab #13: Life in a Watershed.
Wells, Edward. Lab Manual for Environmental Science. 2009. Lab #14: Know Your Neighborhood.
News Videos
Carbon Dioxide’s Impact on Our Oceans, The Brooks/Cole Environmental Science Video Library 2009,
©2011, DVD ISBN-13: 978-0-538-73355-7
Additional Videos
Amazon: IMAX (1997)
Instructor’s Manual for Environmental Science, 15th edition
http://www.bullfrogfilms.com/catalog/ba.html
Conserving America: The Wetlands (PBS, 1994)
Journey to Planet Earth (DVD from PBS, 2003)
http://www.pbs.org/journeytoplanetearth/
Strange Days on Planet Earth (TV Series, National Geographic, 2008)
http://www.pbs.org/strangedays/
The Day After Tomorrow (Movie, 2004)
A climatologist tries to figure out a way to save the world from abrupt global warming.
http://www.amazon.com/The-Day-After-Tomorrow/dp/B000NDMRCS/ref=sr_1_1?s=movies-
tv&ie=UTF8&qid=1312156759&sr=1-1
Web Resources
Climate Central
An exploration of the climate issues.
http://climatecentral.org/about.html
Digital Integration
Correlation to Global Environment Watch
Aquifers Floods Mountains
Climate Change Forests and Deforestation Mountaintop Removal Mining
Coral Reefs Grasslands Oceans and Seas
Deserts and Desertification Gulf of Mexico Oil Spill 2010 Water
Fisheries Lakes, Rivers, and Streams Water Pollution
Fishing Land and Soil Pollution Wetlands
Chapter 7: Climate and Biodiversity
Correlation to Explore More
Aquatic Ecosystems New Orleans
Biodiversity Water Resources
Biomes
Suggested Answers to End of Chapter Questions
Answers will vary but these represent phrases from this chapter. The following are examples of the material
that should be contained in possible student answers to the end of chapter questions. They represent only a
summary overview and serve to highlight the core concepts that are addressed in the text. It should be
anticipated that the students will provide more in-depth and detailed responses to the questions depending
on an individual instructor’s stated expectations.
Review
Core Case Study
1. What are coral reefs and why should we care about them? What is coral bleaching? What are the major
threats to coral reefs?
• Coral reefs are highly productive ecosystems that are dazzling centers of biodiversity.
Section 7-1
2. What is the key concept for this section? Distinguish between weather and climate. Define ocean
currents. Describe three major factors that determine how air circulates in the lower atmosphere.
Explain how varying combinations of temperature and precipitation, along with global air circulation
and ocean currents, lead to the formation of various types of forests, grasslands, and deserts.
• CONCEPT 7-1 Key factors that influence an area’s climate are incoming solar energy, the earth’s
rotation, global patterns of air and water movement, gases in the atmosphere, and the earth’s
surface features.
• Weather is a set of physical conditions of the lower atmosphere such as temperature, precipitation,
humidity, wind speed, cloud cover, and other factors in a given area over a period of hours or
days.
• Climate is an area’s general pattern of atmospheric conditions over periods ranging from at least
three decades to thousands of years.
• Three major factors determine how air circulates in the lower atmosphere:
o Uneven heating of the earth’s surface by the sun.
3. Define and give three examples of a greenhouse gas. What is the greenhouse effect and why is it
important to the earth’s life and climate? What is the rain shadow effect and how can it lead to the
Instructor’s Manual for Environmental Science, 15th edition
formation of deserts? Why do cities tend to have more haze and smog, higher temperatures, and lower
wind speeds than the surrounding countryside?
• Greenhouse gases include several gases in the atmosphere, including water vapor (H2O), carbon
dioxide (CO2), methane (CH4), and nitrous oxide (N2O), which absorb and release heat that warms
the atmosphere.
• The natural greenhouse effect is a warming of the lower atmosphere and the earth’s surface. Some
Section 7-2
4. What are the two the key concepts for this section? What is a biome? Explain why there are three
major types of each of the major biomes (deserts, grasslands, and forests). Explain why biomes are
not uniform. Describe how climate and vegetation vary with latitude and elevation. What is the edge
effect?
• CONCEPT 7-2A Differences in long-term average annual precipitation and temperature lead to
the formation of tropical, temperate, and cold deserts, grasslands, and forests, and largely
determine their locations.
• CONCEPT 7.2B Human activities are disrupting ecosystem and economic services provided by
many of the earth’s deserts, grasslands, forests, and mountains.
• Biomes are large terrestrial regions, each characterized by certain types of climate and dominant
plant life.
5. Explain how the three major types of deserts differ in their climate and vegetation. Why are desert
ecosystems fragile? How do desert plants and animals survive? Explain how the three major types of
grasslands differ in their climate and vegetation. What is a savanna? Why have many of the world’s
temperate grasslands disappeared? What is permafrost? Explain how the three major types of forests
differ in their climate and vegetation. Why is biodiversity so high in tropical rain forests? Explain
why most soils in tropical rain forests hold few plant nutrients. Why does a thick layer of decaying
litter typically cover the floors of temperate deciduous forests?
Chapter 7: Climate and Biodiversity
What are coastal coniferous or temperate rain forests? How do most species of coniferous evergreen
trees survive the cold winters in boreal forests? What important ecological roles do mountains play?
• Tropical deserts are hot and dry most of the year with few plants and a hard, windblown surface
strewn with rocks and some sand.
• Temperate deserts have high daytime temperatures in summer and low in winter and there is more
precipitation than in tropical deserts, with sparse vegetation consisting mostly of widely dispersed,
drought resistant shrubs and cacti or other succulents adapted to the lack of water and temperature
variations.
• Tropical rain forests are found near the equator where hot, moisture-laden air rises and dumps its
moisture; these lush forests have year-round, uniformly warm temperatures, high humidity, and
heavy rainfall almost daily.
• The combination of warmth and high humidity provides for high primary productivity which
encourages high biodiversity.
• About 90% of the nutrients released by this rapid decomposition are quickly taken up and stored
by trees, vines, and other plants. Nutrients that are not taken up are soon leached from the thin
topsoil by the almost daily rainfall.
6. About what percentage of the world’s major terrestrial ecosystems are being degraded or used
unsustainably? Summarize the ways in which human activities have affected the world’s deserts,
grasslands, forests, and mountains.
Instructor’s Manual for Environmental Science, 15th edition
o Some of the major human impacts on terrestrial ecosystems:
o Large desert cities
o Destruction of soil and underground habitat by off-road vehicles
o Depletion of groundwater
o Land disturbance and pollution from mineral extraction
o Conversion to cropland
Section 7-3
7. What is the key concept for this section? What percentage of the earth’s surface is covered with ocean
water? What is an aquatic life zone? Distinguish between a saltwater (marine) life zone and a
freshwater life zone, and give two examples of each. List five factors that determine the types and
numbers of organisms found in the layers of aquatic life zones.
• CONCEPT 7.3 Oceans dominate the planet and provide vital ecosystem and economic services
that are being disrupted by human activities.
• Saltwater in the oceans covers about 71% of the earth’s surface.
8. What major ecosystem and economic services are provided by marine systems? What are the three
major life zones in an ocean? Define and distinguish between the coastal zone and the open sea.
Distinguish between an estuary and a coastal wetland. Explain the ecological and economic importance
of coastal marshes, mangrove forests, and sea-grass beds. Explain the importance of coral reefs.
What is ocean acidification and why is it a threat to coral reefs? Describe the three major zones in the
open sea. List five human activities that pose major threats to marine systems and eight human
activities that threaten coral reefs.
• See Figure 7-18 for a list of the ecological and economic services that marine ecosystems provide.
Chapter 7: Climate and Biodiversity
• Estuaries are where rivers meet the sea. They are partially enclosed bodies of water where
seawater mixes with freshwater.
• Coastal wetlands are coastal land areas covered with water all or part of the year, such as include
river mouths, inlets, bays, and salt marshes in temperate zones, and mangrove forests in tropical
zones.
Section 7-4
9. What is the key concept for this section? Define surface water, runoff, and watershed (drainage basin).
What major ecosystem and economic services do freshwater systems provide? What is a lake? What
four zones are found in deep lakes? Distinguish between oligotrophic and eutrophic lakes. What is
cultural eutrophication? Describe the three zones that a stream passes through as it flows from
highlands to lower elevations. What is a delta? Give three examples of inland wetlands and describe
the ecological and economic importance of such wetlands. List four ways in which human activities
are disrupting and degrading many of the ecosystem and economic services provided by freshwater
rivers, lakes, and wetlands. How is Alexandra Cousteau attempting to educate people about the
importance of aquatic systems?
• CONCEPT 7-4 Freshwater lakes, rivers, and wetlands provide important ecological and economic
services that are being disrupted by human activities
• Precipitation that does not sink into the ground or evaporate is surface water. It becomes runoff
when it flows into streams. A watershed, or drainage basin, is the land area that delivers runoff,
sediment, and dissolved substances to a stream.
Instructor’s Manual for Environmental Science, 15th edition
• Three zones in the downhill flow of water are: source zone, which contains mountain (headwater)
streams; transition zone, which contains wider, lower-elevation streams; and floodplain zone,
which contains rivers that empty into larger rivers or into the ocean.
• A delta is an area at the mouth of a river built up by deposited sediment and often containing
estuaries and coastal wetlands.
• Three examples of inland wetlands:
• Inland wetlands are ecologically import because they provide a number of free ecological and
economic services, which include:
o Filtering and degrading toxic wastes and pollutants.
o Reducing flooding and erosion by absorbing storm water and releasing it slowly and by
• Human activities are disrupting and degrading many of the ecological and economic services
provided by freshwater rivers, lakes, and wetlands in four major ways.
o Dams and canals alter and destroy terrestrial and aquatic wildlife habitats along rivers and in
coastal deltas and estuaries by reducing water flow and increasing damage from coastal
storms.
o Flood control levees and dikes built along rivers disconnect the rivers from their floodplains,
• The focus of Alexandra’s work is advocating the importance of conservation and sustainable
management of water in order to preserve a healthy planet. She seeks to make water one of the
defining issues of this century, stating: “We live on a water planet, which means we’re all
downstream from one another. Where water comes from, where it goes, and its quality is
intricately connected to our quality of life.”
10. What are this chapter’s three big ideas? Explain how terrestrial and aquatic systems are living
examples of the three principles of sustainability.
• Differences in climate, based mostly on long-term differences in average temperature and
precipitation, largely determine the types and locations of the earth’s deserts, grasslands, and
forests.
Chapter 7: Climate and Biodiversity
Critical Thinking
1. What are three steps that governments and private interests could take to protect the world’s remaining
coral reefs (Core Case Study)?
2. Why do most animals in a tropical rain forest live in its trees?
3. How might the distribution of the world’s forests, grasslands, and deserts shown in Figure 7.8 differ if
the prevailing winds shown in Figure 7.3 did not exist?
4. Which biomes are best suited for (a) raising crops and (b) grazing livestock? Use the three scientific
principles of sustainability to come up with three guidelines for growing crops and grazing livestock
more sustainably in these biomes.
(a) Temperate grasslands are best suited for growing crops. Sustainability guidelines to consider are:
grow crops that are native to the area and that thrive under the normal rainfall and sunlight for the area;
grow a wide variety of crops using polyculture, which enhances biodiversity; use best management
5. What type of biome do you live in? (If you live in a developed area, what type of biome was the area
before it was developed?) List three ways in which your lifestyle could be contributing to the
degradation of this biome. What are three lifestyle changes that you could make in order to reduce your
contribution?
6. You are a defense attorney arguing in court for sparing a tropical rain forest from being cut down. Give
your three best arguments for the defense of this ecosystem. Do the same for sparing a threatened coral
reef (Core Case Study). If you had to choose between protecting a tropical rain forest and a coral reef,
Instructor’s Manual for Environmental Science, 15th edition
which one would you select? Explain.
Compelling arguments for the defense of tropical forests are that an intact tropical forest ecosystem
contains more biodiversity per unit area than any other ecosystem; these forests help regulate global
weather patterns; new medicinal discoveries; and forests act as carbon sinks, tying up carbon that
would otherwise be contributing to the climate change phenomenon.
7. Why is ocean acidification considered to be a very serious problem? If acidity levels in the ocean rise
sharply during your lifetime, how might this affect you? Can you think of ways in which you might be
contributing to this problem? What could you do to reduce your impact?
8. Suppose you have a friend who owns property that includes a freshwater wetland and the friend tells
you she is planning to fill the wetland to make more room for her lawn and garden. What would you
say to this friend?
I would tell my friend to leave the wetland alone. Inland wetlands provide a number of free ecosystem
and economic services, which include:
• filtering and degrading toxic wastes and pollutants;
• reducing flooding and erosion by absorbing stormwater and releasing it slowly, and by absorbing
Global Environment Watch Exercise
Search for Coral Reefs and use the topic portal to find information on (a) trends in the global rate of
coral reef destruction; (b) what areas of the world are seeing rising rates and what areas are seeing
falling rates; and (c) what is being done to protect them in various areas. Write a report on your
findings.
Chapter 7: Climate and Biodiversity
Data Analysis Answers
1. In what month (or months) does the most precipitation fall in each of these areas?
2. What are the driest months in each of these areas?
3. What is the coldest month in the tropical grassland?
4. What is the warmest month in the temperate grassland?
