Chapter 5
Climate and Terrestrial
Biodiversity
Chapter Overview Questions
 What
factors the earth’s climate?
 How does climate determine where the
earth’s major biome’s are found?
 What are the major types of desert biomes?
 What are the major types of grassland
biomes?
Chapter Overview Questions (cont’d)
 What
are the major types of forest and
mountain biomes?
 How have human activities affected the
world’s desert, grassland, forest, and
mountain biomes?
Core Case Study
Blowing in the Wind:
A Story of Connections
 Wind
connects
most life on earth.


Keeps tropics from
being unbearably
hot.
Prevents rest of
world from
freezing.
Figure 5-1
Weather and climate
 Weather
is a local area’s short-term physical
conditions such as temperature and
precipitation.
 Climate is a region’s average weather
conditions over a long time.


Latitude and elevation help determine climate.
Average temp and average precipitation are two
main factors.
 “Climate
is what we expect, weather is what we
get” – Mark Twain.
Earth’s Current Climate Zones
Figure 5-2
Distributing Heat

Global air circulation is affected by the uneven
heating of the earth’s surface by solar energy,
seasonal changes in temperature and precipitation.
 Four major factors determine global air circulation
patterns:




Uneven heating of the earth’s surface by the sun
Seasonal changes in temperature and precipitation
Rotation of the earth on its axis causes Coriolis effect
Properties of air, water and land (convection currents)
Figure 5-3
Spring
(sun aims directly
at equator)
Winter
(northern hemisphere 23.5 °
tilts away from sun)
Solar
radiation
Summer
(northern hemisphere
tilts toward sun)
Fall
(sun aims directly at equator)
Fig. 5-3, p. 102
Coriolis Effect

Global air circulation is
affected by the rotation of
the earth on its axis.
 Atmospheric regions called
cells are made from belts
of prevailing winds (major
winds continuously
blowing) that distribute
heat and moisture
 Six giant convection cells
on earth
Figure 5-4
Cell 3 North
Cold,
dry air
falls
Moist air rises — rain
Polar cap
Arctic tundra
Evergreen
60°coniferous forest
Temperate deciduous
forest and grassland
30°Tropical Desert
Cell 2 North
Cool, dry
air falls
Cell 1 North
deciduous
forest
0°Equator
Tropical
deciduous
30°forest
Tropical
rain forest
Desert
Temperate
deciduous
60°forest and
grassland
Cell 1 South
Cool, dry
air falls
Cell 2 South
Polar cap
Cold,
dry air
falls
Moist air rises,
cools, and releases
Moisture as rain
Moist air rises — rain
Cell 3 South
Fig. 5-6, p. 103
LOW
PRESSURE
Cool, dry
air
HIGH
PRESSURE
Heat released
radiates to space Condensation
Falls, is compressed,
warms
and
precipitation
Rises, expands, cools
Warm,
dry air
Hot, wet
air
Flows toward low pressure,
picks up moisture and heat
HIGH
Moist surface warmed
PRESSURE
by sun
LOW
PRESSURE
Fig. 5-5, p. 103
Ocean Currents
 Ocean
currents influence climate by
distributing heat from place to place and
mixing and distributing nutrients.
 Flow clockwise in northern hemisphere,
counterclockwise in southern.
 Gulf Stream transports 25 times more water
than all of the world’s rivers combined.
Figure 5-7
(a) Rays of sunlight
penetrate the lower
atmosphere and
warm the earth's
surface.
(b) The earth's surface absorbs
much of the incoming solar radiation
and degrades it to longer-wavelength
infrared (IR) radiation, which rises
into the lower atmosphere. Some of this
IR radiation escapes into space as heat,
and some is absorbed by molecules of
greenhouse gases and emitted as even
longer-wavelength IR radiation, which
warms the lower atmosphere.
(c) As concentrations of
greenhouse gases rise,
their molecules absorb
and emit more infrared
radiation, which adds
more heat to the lower
atmosphere.
Fig. 5-7, p. 104
Ocean Currents:
Distributing Heat and Nutrients
 Global

warming:
Considerable scientific evidence and climate
models indicate that large inputs of greenhouse
gases from anthropogenic activities into the
troposphere can enhance the natural
greenhouse effect and change the earth’s climate
in your lifetime.
Topography and Local Climate:
Land Matters
 Interactions
between land and oceans and
disruptions of airflows by mountains and
cities affect local climates.
Figure 5-8
Biomes

Different climates lead to different communities of
organisms, especially vegetation.
 Biomes – large terrestrial regions characterized by
similar climate, soil, plants, and animals.
 Each biome contains many ecosystems whose
communities have adapted to differences in climate,
soil, and other environmental factors.
 Climates have changed over the earth’s history.
 Temperature, precipitation, and soil type are the most
important factors in producing the type of biome.
 Biomes are not uniform; they consist of a mosaic of
patches
Tropic of
Cancer
Equator
High mountains
Polar ice
Polar grassland (arctic
tundra)
Temperate grassland
Tropical grassland
(savanna)
Chaparral
Coniferous forest
Temperate deciduous forest
Tropical forest
Desert
Tropic of
Capricorn
Fig. 5-9, p. 106
Polar
Tundra
Subpolar
Temperate
Coniferous
forest
Desert
Deciduous
Forest
Grassland
Chaparral
Tropical
Desert
Rain forest
Savanna
Tropical
seasonal
forest
Scrubland
Fig. 5-10, p. 107
Effects of elevation and latitude on biomes
 Parallel
changes occur in vegetation type
occur when we travel from the equator to the
poles or from lowlands to mountaintops.
Figure 5-11
DESERT BIOMES
 Deserts
are areas where evaporation
exceeds precipitation.
 Deserts have little precipitation and little
vegetation.

Found in tropical, temperate and polar regions.
 Desert
plants have adaptations that help
them stay cool and get enough water.
 Cover about 30% of the earth’s land surface
DESERT BIOMES
 Variations
in
annual
temperature (red)
and precipitation
(blue) in tropical,
temperate and
cold deserts.
Figure 5-12
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Tropical Desert
Fig. 5-12a, p. 109
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Temperate Desert
Fig. 5-12b, p. 109
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (°C)
Polar Desert
Fig. 5-12c, p. 109

Deserts
The flora and fauna
in desert
ecosystems adapt to
their environment
through their
behavior and
physiology.
 Adaptations include
two main themes:
 Beat the heat
 Every drop of
water counts
Figure 5-13
Desert adaptations
 Plants:




Waxy leaves
Deep roots
Store water
Open stomatta only at night
 Animals:



Hide during day
Thick outer covering to prevent water loss
Get water from dew or food
 Fragile

ecosystems
Soil nutrients take a long time to recover
GRASSLANDS AND CHAPARRAL
BIOMES
 Variations
in
annual
temperature
(red) and
precipitation
(blue).
Figure 5-14
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Tropical grassland (savanna)
Fig. 5-14a, p. 112
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Temperate grassland
Fig. 5-14b, p. 112
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Polar grassland (arctic tundra)
Fig. 5-14c, p. 112
GRASSLANDS AND CHAPARRAL
BIOMES
 Grasslands
(prairies) occur in areas too moist
for desert and too dry for forests.
 Savannas are tropical grasslands with
scattered tree and herds of hoofed animals.
 Migrations to find food and water in response
to seasonal changes.
 Plants can survive extreme moisture and
temperature levels.
Temperate Grasslands
 The
cold winters and
hot dry summers
have deep and fertile
soil that make them
ideal for growing
crops and grazing
cattle.
 Short-grass and tallgrass praries.
Figure 5-15
Golden eagle
Pronghorn
antelope
Grasshopper
sparrow
Coyote
Grasshopper
Blue stem
grass
Prairie
dog
Bacteria
Fungi
Prairie
Coneflower
Producer
to primary
consumer
Primary
to
secondary
consumer
Secondary
to
higher-level
consumer
All producers and
consumers to
decomposers
Fig. 5-15, p. 113
Polar Grasslands

Polar grasslands are
covered with ice and snow
except during a 6-8 week
summer.
 Permafrost can form:
underground soil that
stays frozen for more than
2 consecutive years.
 Global warming has
melted some permafrost,
releasing CH4.
 Soil recovers slowly;
biome is fragile. Figure 5-17
Chaparral
 Chaparral
has a
moderate climate but its
dense thickets of spiny
shrubs are subject to
periodic fires.
 Thin soil, not very fertile.
Figure 5-18
FOREST BIOMES

Variations in annual
temperature (red) and
precipitation (blue) in
tropical, temperate,
and polar forests.
 Forests have enough
precipitation to support
stands of trees and
are found in tropical,
temperate, and polar
regions.
Figure 5-19
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Tropical rain forest
Fig. 5-19a, p. 116
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Temperate deciduous forest
Fig. 5-19b, p. 116
Freezing point
Month
Mean monthly precipitation (mm)
Mean monthly temperature (C)
Polar evergreen coniferous forest
(boreal forest, taiga)
Fig. 5-19c, p. 116
Tropical Rain Forest

Tropical rain forests have
heavy rainfall and a rich
diversity of species.
 Found near the equator.
 Have year-round
uniformity warm
temperatures and high
humidity.
 Vast amount of biodiversity.
 High net primary productivity.
 2% of earth’s land surface,
half of the earth’s terrestrial
species reside here.
Figure 5-20
Tropical Rain Forest
 Filling
such niches enables species to avoid
or minimize competition and coexist
Figure 5-21
Temperate Deciduous Forest
 Most
of the trees
survive winter by
dropping their
leaves, which
decay and
produce a nutrientrich soil.
Figure 5-22
Evergreen Coniferous Forests
 Consist
mostly of
cone-bearing
evergreen trees that
keep their needles
year-round to help
the trees survive
long and cold
winters.
Figure 5-23
Temperate Rain Forests
 Coastal
areas support huge cone-bearing
evergreen trees such as redwoods and
Douglas fir in a cool moist environment.
Figure 5-24
MOUNTAIN BIOMES
 High-elevation
islands of
biodiversity
 Often have snow-covered
peaks that reflect solar
radiation and gradually
release water to lowerelevation streams and
ecosystems.
 Plants hold back erosion.
 Contain majority of earth’s
forests.
Figure 5-25
Human impact
 Human
activities have damaged or disturbed
more than half of the world’s terrestrial
ecosystems.
 Humans have had a number of specific harmful
effects on the world’s deserts, grasslands,
forests, and mountains.
 Humans use, waste, or destroy 10-55% of the
net primary productivity of earth’s terrestrial
ecosystems.
 60% of the world’s major terrestrial ecosystems
are being degraded/used unsustainably.
Natural Capital Degradation
Desert
Large desert cities
Soil destruction by off-road
vehicles
Soil salinization from
irrigation
Depletion of groundwater
Land disturbance and
pollution from mineral
extraction
Fig. 5-26, p. 123
Natural Capital Degradation
Grasslands
Conversion to cropland
Release of CO2 to atmosphere
from grassland burning
Overgrazing by livestock
Oil production and off-road
vehicles in arctic tundra
Fig. 5-27, p. 123
Natural Capital Degradation
Forests
Clearing for agriculture, livestock
grazing, timber, and urban
development
Conversion of diverse forests to tree
plantations
Damage from off-road vehicles
Pollution of forest streams
Fig. 5-28, p. 124
Natural Capital Degradation
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
Fig. 5-29, p. 124