MILLER/SPOOLMAN
LIVING IN THE ENVIRONMENT
17TH
Chapter 7
Climate and Biodiversity
Core Case Study: Different Climates
Support Different Life Forms
• Climate -- long-term temperature and precipitation
patterns – determines which plants and animals can
live where
• Tropical: equator, intense sunlight
• Polar: poles, little sunlight
• Temperate: in-between tropical and polar
Three Major Climate Zones
Fig. 7-1, p. 147
7-1 What Factors Influence Climate?
• Concept 7-1 Key factors that determine 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.
The Earth Has Many Different
Climates
• Weather Set of physical conditions in the troposphere (the lower
atmosphere):
• Temperature, precipitation, wind speed, cloud cover,
Humidity
• Time Span: Hours to days
• Climate
• Area’s general pattern of atmospheric conditions over
periods ranging from 3 decades to thousands of years.
• Climate is the SUM of weather conditions in a given
area, averaged over a long period of time.
Natural Capital: Generalized Map of the Earth’s Current
Climate Zones
Fig. 7-2, p. 149
Arctic
Circle
Tropic of
Cancer
Tropic of
Capricorn
Antarctic
Circle
Polar (ice)
Warm temperate
Subarctic (snow)
Dry
Cool temperate
Tropical
Highland
Major upwelling zones
Warm ocean current
River
Cold ocean current
Fig. 7-2, p. 149
The Earth Has Many Different
Climates
• Air circulation in lower atmosphere due to
1.
Uneven heating of the earth’s surface by sun: Sun hits the
earth more directly at the equator, so smaller areas are
delivered more heat. At poles the light is indirectly angled so
the heat is spread over a larger area.
2. Rotation of the earth on its axis: Equator spins faster than
regions north or regions south. Locations farther from the
equator spin slower.
The atmosphere over these areas are divided into areas called
cells.
Cells: Distinguished by their differing directions of air
movement.
3. Properties of air, water, and land: Heat from the sun
evaporates water and transfers heat to the atmosphere. This
transfer forms convection cells that circulate heat, air, and
moisture from place to place and vertically.
Global Air Circulation
Fig. 7-3, p. 149
Moist air rises, cools,
and releases moisture
as rain
Polar cap
Cold deserts
60°N
The highest solar
energy input is at the
equator.
Solar energy
Westerlies
30°N
Northeast trades
Evergreen
coniferous forest
Temperate deciduous
forest and grassland
Hot desert
Tropical deciduous forest
Equator
0°
Tropical rain forest
Air cools and
descends at lower
latitudes.
Warm air rises and
moves toward the
poles.
Tropical deciduous
forest
Hot desert
Southeast trades
30°S
Westerlies
Temperate deciduous
forest and grassland
Cold deserts
Air cools and
descends at lower
latitudes.
60°S
Polar cap
Fig. 7-3, p. 149
LOW PRESSURE
Cool,
dry air
HIGH PRESSURE
Heat released
radiates to space
Falls, is
compressed,
warms
Warm,
dry air
HIGH PRESSURE
Condensation
and
precipitation
Rises,
expands,
cools
Flows toward low
pressure, picks up
moisture and heat
Moist surface
warmed by sun
Hot,
wet air
LOW PRESSURE
Fig. 7-4, p. 150
Energy Transfer by Convection
in the Atmosphere
Fig. 7-4, p. 150
The Earth Has Many Different
Climates
• Ocean currents
•
•
•
•
Prevailing winds
Earth’s rotation
Redistribution of heat from the sun due to differing densities
of warm vs. cool water
Surface currents and deep currents
Connected Deep and Shallow Ocean Currents
Fig. 7-5, p. 150
Warm, less salty,
shallow current
Cold, salty,
deep current
Fig. 7-5, p. 150
The Earth Has Many Different
Climates
• El Niño-Southern Oscillation
• Every few years
• Prevailing winds in tropical Pacific Ocean change
direction
• Affects much of earth’s weather for 1-2 years
• Link between air circulation, ocean currents, and
biomes
Normal and El Niño Conditions
Figure 4, Supplement 7
Impact of El Nino-Southern Oscillation
Figure 5, Supplement 7
Greenhouse Gases Warm the
Lower Atmosphere
• Greenhouse gases
•
•
•
•
H2O
CO2
CH4
N2O
• Natural greenhouse effect
• Gases keep earth habitable
• Human-enhanced global warming
Flow of Energy to and from the Earth
Fig. 3-4, p. 57
Earth’s Surface Features Affect Local
Climates
• Differential heat absorption by land and water
• Land and sea breezes
• Rain shadow effect
• Most precipitation falls on the windward side of
mountain ranges
• Deserts leeward
• Cities create microclimates
Rain Shadow Effect
Fig. 7-6, p. 152
Prevailing winds
pick up moisture
from an ocean.
On the windward side of
a mountain range, air
rises, cools, and releases
moisture.
On the leeward side of the
mountain range, air descends,
warms, and releases little
moisture, causing rain shadow
effect.
Fig. 7-6, p. 152
7-2 How Does Climate Affect the Nature
and Locations of Biomes?
• Concept 7-2 Differences in average annual
precipitation and temperature lead to the formation
of tropical, temperate, and cold deserts, grasslands,
and forests, and largely determine their locations.
Climate Helps Determine Where
Organisms Can Live
• Major biomes: large land regions with certain types
of climate and dominant plant life
• Not uniform
• Mosaic of patches
• Latitude and elevation
• Annual precipitation
• Temperature
The Earth’s Major Biomes
Fig. 7-7, p. 153
North America Biomes
Figure 3, Supplement 8
Generalized Effects of Elevation and Latitude on Climate
and Biomes
Fig. 7-8, p. 153
Elevation
Mountain ice
and snow
Tundra (herbs,
lichens, mosses)
Coniferous Forest
Latitude (south to north)
Deciduous Forest
Tropical Forest
Tropical
Forest
Deciduous
Forest
Coniferous
Forest
Tundra
(herbs,
lichens,
mosses)
Polar
ice and
snow
Fig. 7-8, p. 153
Elevation Mountain ice
and snow
Tundra (herbs,
lichens,
mosses)
Coniferous
Forest
Deciduous
Forest
Latitude
Tropical
Forest
Tropical
Forest
Deciduous
Forest
Coniferous
Forest
Tundra
(herbs,
lichens,
mosses)
Polar ice
and snow
Stepped Art
Fig. 7-8, p. 153
Natural Capital: Average Precipitation and Average
Temperature as Limiting Factors
Fig. 7-9, p. 154
Cold
Arctic tundra
Cold desert
Evergreen coniferous forest
Temperate
desert
Temperate deciduous forest
Chaparral
Hot Wet
Temperate grassland
Tropical desert
Tropical rain forest
Dry
Tropical grassland (savanna)
Fig. 7-9, p. 154
Global Plant Biodiversity
Figure 6, Supplement 8
Tropic of
Cancer
High mountains
Equator
Polar ice
Arctic tundra (cold grassland)
Temperate grassland
Tropical grassland (savanna)
Chaparral
Tropic of
Capricorn
Coniferous forest
Temperate deciduous forest
Temperate rain forest
Tropical rain forest
Tropical dry forest
Desert
Fig. 7-7, p. 153
There Are Three Major Types of
Deserts
1. Tropical deserts
2. Temperate deserts
3. Cold deserts
•
Fragile ecosystem
•
•
•
•
Slow plant growth
Low species diversity
Slow nutrient recycling
Lack of water
Climate Graphs of Three Types of Deserts
Fig. 7-10, p. 155
Stepped Art
Fig. 7-10, p. 155
Temperate Desert Ecosystem in North America
Figure 1, Supplement 6
Science Focus: Staying Alive
in the Desert
• Beat the heat/every drop of water counts
• Plant adaptations
• Succulents
• Deep tap roots
• Animal strategies and adaptations
• Physiology and anatomy
• Behavior
Wildflowers Bloom after Rain in Arizona
Fig. 7-A, p. 156
There Are Three Major Types of
Grasslands (1)
1. Tropical
2. Temperate
3. Cold (arctic tundra)
Climate Graphs of Tropical, Temperate, and Cold
Grasslands
Fig. 7-11, p. 157
Stepped Art
Fig. 7-11, p. 157
There Are Three Major Types of
Grasslands (2)
• Tropical
• Savanna
• Grazing animals
• Browsing animals
• Temperate
•
•
•
•
Cold winters and hot and dry summers
Tall-grass prairies
Short-grass prairies
Often converted to farmland
Temperate Tall-Grass Prairie Ecosystem in North America
Figure 2, Supplement 6
There Are Three Major Types of
Grasslands (3)
• Arctic tundra: fragile biome
•
•
•
•
Plants close to ground to conserve heat
Most growth in short summer
Animals have thick fur
Permafrost
• Underground soil that stays frozen
• Alpine tundra: above tree line in mountains
Monoculture Crop Replacing Biologically Diverse
Temperate Grassland
Fig. 7-12, p. 158
Temperate Shrubland: Nice Climate,
Risky Place to Live
• Chaparral
• Near the sea: nice climate
• Prone to fires in the dry season
There Are Three Major Types of
Forests (1)
1. Tropical
2. Temperate
3. Cold
• Northern coniferous and boreal
Climate Graphs of Tropical, Temperate, and Cold Forests
Fig. 7-13, p. 160
Stepped Art
Fig. 7-13, p. 160
There Are Three Major Types of
Forests (2)
• Tropical rain forests
•
•
•
•
•
Temperature and moisture
Stratification of specialized plant and animal niches
Little wind: significance
Rapid recycling of scarce soil nutrients
Impact of human activities
Tropical Rain Forest Ecosystem
Fig. 7-14, p. 161
Blue and gold
macaw
Ocelot
Harpy
eagle
Climbing
monstera
palm
Slaty-tailed
trogon
Squirrel
monkeys
Katydid
Tree frog
Green tree
snake
Snail
Ants
Bacteria
Bromeliad
Fungi
Producer
to primary
consumer
Primary to
secondary
consumer
Secondary to
higher-level
consumer
All producers
and consumers
to decomposers
Fig. 7-14, p. 161
Niche Stratification in a Tropical Rain Forest
Fig. 7-15, p. 162
45
Emergent
layer
Harpy
eagle
40
35
Toco
toucan
Canopy
Height (meters)
30
25
20
Understory
Wooly
opossum
15
10
Brazilian tapir
5
0
Black-crowned
antpitta
Shrub layer
Ground
layer
Fig. 7-15, p. 162
There Are Three Major Types of
Forests (3)
• Temperate deciduous forests
•
•
•
•
Temperature and moisture
Broad-leaf trees
Slow rate of decomposition: significance
Impact of human activities
Temperate Deciduous Forest Ecosystem in North America
Figure 4, Supplement 6
There Are Three Major Types of
Forests (4)
• Evergreen coniferous forests: boreal and taigas
• Temperature and moisture
• Few species of cone: bearing trees
• Slow decomposition: significance
• Coastal coniferous forest
• Temperate rain forests
Evergreen Coniferous Forest Ecosystem in North America
Figure 5, Supplement 6
Temperate Rain Forest in Washington State
Fig. 7-16, p. 163
Mountains Play Important
Ecological Roles
• Majority of the world’s forests
• Islands of biodiversity
• Habitats for endemic species
• Help regulate the earth’s climate
• Major storehouses of water
• Role in hydrologic cycle
Mount Rainier National Park in Washington State
Fig. 7-17, p. 163
7-3 How Have We Affected the Word’s
Terrestrial Ecosystems?
• Concept 7-3 In many areas, human activities are
impairing ecological and economic services provided
by the earth’s deserts, grasslands, forests, and
mountains.
Humans Have Disturbed Most of
the Earth’s Lands
• Deserts
• Grasslands
• Forests
• Mountains
Major Human Impacts on Terrestrial Ecosystems
Fig. 7-18, p. 165
Natural Capital Degradation
Major Human Impacts on Terrestrial Ecosystems
Deserts
Large desert cities
Grasslands
Forests
Conversion to
cropland
Clearing for
agriculture, livestock
grazing, timber, and
urban development
Destruction of soil and
underground habitat by Release of CO2 to
off-road vehicles
atmosphere from
burning grassland
Soil salinization from
irrigation
Depletion of
groundwater
Land disturbance and
pollution from mineral
extraction
Mountains
Agriculture
Timber and mineral
extraction
Hydroelectric dams and
reservoirs
Conversion of diverse
forests to tree
Increasing tourism
Overgrazing by
plantations
Air pollution blowing in from urban
livestock
areas and power plants
Damage from offOil production and road vehicles
Soil damage from off-road
off-road vehicles
vehicles
Pollution of forest
in arctic tundra
streams
Water supplies threatened by
glacial melting
Fig. 7-18, p. 165
NATURAL CAPITAL
DEGRADATION
Major Human Impacts on Terrestrial Ecosystems
Deserts
Grasslands
Forests
Clearing for
Large desert cities Conversion
agriculture,
to cropland
Soil destruction by Release of CO2 livestock grazing,
off-road vehicles
to atmosphere timber, and urban
from burning development
Soil salinization
grassland
Conversion of
from irrigation
diverse forests to
Overgrazing tree plantations
Depletion of
by livestock
groundwater
Damage from offOil production road vehicles
Land disturbance and off-road
and pollution from vehicles in
Pollution of
mineral extraction arctic tundra forest streams
Mountains
Agriculture
Timber extraction
Mineral extraction
Hydroelectric dams
and reservoirs
Increasing tourism
Urban air pollution
Increased ultraviolet
radiation from ozone
depletion
Soil damage from off-road
vehicles
Stepped Art
Fig. 7-18, p. 165
Three Big Ideas
1. 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.
2. The earth’s terrestrial systems provide important
ecological and economic services.
Three Big Ideas
3. Human activities are degrading and disrupting
many of the ecological and economic services
provided by the earth’s terrestrial ecosystems.