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Chapter 35 Major Ecosystems of the Biosphere
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
35.1 Climate and the Biosphere
• Climate
– Prevailing weather conditions in a particular
region
– Dictated by temperature and rainfall,
influenced by following factors:
– Variations in solar radiation distribution
– Other effects – topography, proximity to water
bodies
35.1 Climate and the Biosphere
• Effect of Solar Radiation
– The sun’s rays are more direct at the equator
and more spread out nearing the poles
• Makes tropical regions warmer than temperate
regions
– The Earth is on a slight tilt
• As the Earth orbits, different areas are tilted toward
or away from the sun – determines seasons
equator
equator
North
Pole
South
Pole
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
23
sun
Summer solstice
Northern Hemisphere
tilts toward sun, June
Vernal equinox
Sun aims directly
at equator, March Winter solstice
Northern Hemisphere
tilts away from sun,
December
Autumnal equinox
Sun aims directly
at equator, September
35.1 Climate and the Biosphere
• Effect of Solar Radiation
– The flow of warm and cold air form three large
circulation patterns in each hemisphere
– The direction in which the air rises and cools
determines the direction of the wind
• Northern Hemisphere: Large scale winds
generally move clockwise, in the southern
hemisphere they move counterclockwise
0°
Ascending
moist air
cools and
loses moisture.
Descending
dry air warms
and retains
moisture.
30°S
60°S
30°N
60°N
northeast
winds
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
35.1 Climate and the Biosphere
• Other Effects
– Topography - physical features of land
• Mountains
– The windward side receives more rain than the
leeward side
– Create a rain shadow on leeward side
– As air blows up the mountain, it rises and cools
– As air descends the other side of the mountain,
it picks up moisture and produces clear
weather
Formation of a Rain Shadow Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
condensation
rain shadow
dry air
windward side leeward side
35.1 Climate and the Biosphere
• Other Effects
– Topography • Monsoon Climate in southern Asia
– Land heats more rapidly than the waters of the
Indian Ocean during spring
– Gigantic circulation of air: warm air rises over
the land, and cooler wet air comes in off the
ocean to replace it wet ocean winds blow
onshore for almost half the year
– Rainfall heavin on the windward side of hills
– Pattern reversed in November
35.1 Climate and the Biosphere
• Other Effects
– Topography
• Lake Effect
– In the winter, arctic winds blowing over the
Great Lakes become warm and moisture-laden
– When these winds rise and lose their moisture,
snow begins to fall
– Buffalo, New York, gets heavy snowfall due to
lake effect ~90-140 days
35.2 Terrestrial Ecosystems
• Biome - major type of terrestrial
ecosystem
– Depends on latitude, longitude and rainfall
Characteristic mix of plants and animals
adapted to live there
– Forms particular pattern when plotted
according to their mean annual temperature
and mean annual precipitation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
savanna
grassland
temperate
deciduous
forest
taiga
tundra
Arctic-
alpine
cold
temperate
temperate
rain forest
tropical
rain forest
tropical
seasonal
forest
Mean Annual Precipitation (cm)
desert
–15
–10
–5
0
5
10
15
20
25
30 50 100 150 200 250 300 350 400 450
warm
temperate
Mean
An
nu
al
Tem
pera
ture
(°C
)
desert
semidesert
savanna
temperate grassland
shrubland
tropical rain forest
tropical seasonal forest
tropical deciduous forest
temperate rain forest
temperate deciduous forest
mountain zone
taiga
tundra
polar ice
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
35.2 Terrestrial Ecosystems
• Distribution of the biomes and their
corresponding communities of organisms
is determined by:
– Differences in climate due to the distribution
of solar radiation
– Water
– Defining topographical features
• Both latitude and altitude are responsible
for temperature gradients
ice
tundra ice
Increasing Latitude
alpine
tundra
montane
coniferous
forest
deciduous
forest
tropical
forest
temperate
deciduous
forest coniferous
forest
Incre
asin
g A
ltit
ud
e
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
35.2 Terrestrial Ecosystems
• Tundra
– Encircles Arctic region south of ice-covered polar
seas in the Northern Hemisphere
– Very cold and dark most of the year—short growing
season, precipitation is minimal
– Permafrost prevents water drainage
– Vegetation
• Lichens, short grasses, dwarf shrubs
– Animals
• Caribou, reindeer, wolves, polar bears
Tundra
35.2 Terrestrial Ecosystems
• Coniferous Forests
– Taiga
• Northern part of North America and Eurasia
• Trees are well adapted to the cold climate
– Needles (reduced leaves), thick bark
• Vegetation
– Cone-bearing trees: pine, firs, spruce
– Mosses, lichens
• Animals
– Bears, deer, moose, beavers, wolves, birds
35.2 Terrestrial Ecosystems
• Coniferous Forests
– Montane coniferous forest - near
mountaintops
• Wolverine and mountain lion
– Temperate Rainforest
• Western coast of the United States and Canada
• Plentiful rainfall and rich soil have produced some
of the tallest conifer trees ever known
• Old-growth forest, trees are >150 years old- 800
Coniferous Forest
35.2 Terrestrial Ecosystems
• Temperate Deciduous Forests – Eastern North America, Europe, Eastern Asia
– Well-defined seasons, long growing season, relatively
high precipitation
– Vegetation
• Oak, beech, maple, and other broad-leaf deciduous trees
• Tall trees form canopy, shrubs and shorter trees below
• Lichens, ferns on forest floor
– Animals
• Squirrels, rabbits, chipmunks, and other small herbivores
• Beaver, red foxes, deer, and black bears
Temperate Deciduous Forests
35.2 Terrestrial Ecosystems
• Tropical Forests
– South America, Africa, Indo-Malayan region
– Weather is always warm, abundant rainfall
– Biome with the greatest diversity of species of
plants and animals
– Complex structure, many levels of life
• Many animals live in the trees
• Epiphytes are plants that grow on other plants but
usually have roots of their own that absorb mineral
and moisture leached from the canopy
Tropical Rain Forests
35.2 Terrestrial Ecosystems
• Shrublands
– Tend to occur along coasts that have dry
summers and receive most of their rainfall in
winter
– Shrubs with waxy leaves, adapted to arid
conditions
• Regrow after a fire
– Animals include coyotes, jackrabbits, gophers
and other rodents
Shrublands
35.2 Terrestrial Ecosystems
• Grasslands
– Rainfall is greater than 25 cm/year but not
enough to support trees
– Grasses well adapted to changing
environment
– Russian steppes
– North American prairies
– African savanna
– Animals include bison and small mammals
The Prairie
The Savanna
35.2 Terrestrial Ecosystems
• Deserts
– Usually found at latitudes of about 30°, in both
the Northern and Southern Hemispheres
– Annual rainfall is less than 25 cm
– Hot days and cold nights
– Most deserts have a variety of plants
• Succulent cacti and nonsucculent sagebrush
– Animals
• Many are burrowing animals
• Nocturnal to avoid heat
Deserts
35.3 Aquatic Ecosystems
• Two Main Types
– Freshwater (inland) ex. lakes
– Saltwater (usually marine) ex. oceans
• Brackish water is a mixture of fresh and salt water
– Coastal Ecosystems
35.3 Aquatic Ecosystems
• Lakes
– Freshwater
– Classified by their
nutrient abundance
• Oligotrophic
(nutrient-poor)
• Eutrophic (nutrient-
rich)
• In the temperate zone, deep lakes
are stratified in the summer and
winter
• Vertical stratification and seasonal
change of temperatures in a lake
basin influence the seasonal
distribution of fish and other aquatic
life
35.3 Aquatic Ecosystems
35.3 Aquatic Ecosystems Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Summer stratification
Fall overturn Spring overturn
wind
wind
wind
wind
ice
epilimnion 24–25°C
thermocline 13–18°C
hypolimnion
5–8°C
2–3°C
most of lake
4°C
Winter stratification
Zones of a Lake Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
surface organisms
fishes
insect larvae
phytoplankton
zooplankton
water strider
northern pike
clinging
organisms
Benthic
Zone
Littoral
Zone
Limnetic
Zone
Profundal
Zone
bottom-dwelling
organisms
(pike): © Robert Maier/Animals Animals; (water strider): © Frank Greenaway/Getty Images
35.3 Aquatic Ecosystems
• Coastal Ecosystems
– Estuaries
• Partially enclosed body of water where fresh and
salt water mix
• Coastal bays, tidal marshes, and lagoons
• “Nurseries” of the sea
– Abundance of nutrients
– Half of all marine fish mature in estuaries
– Feeding grounds of many birds, fish, shellfish
Estuary Structure and Function
white shrimp
phytoplankton
freshwater
input freshwater
input
spawning
and nursery spawning
and nursery
ocean
water
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(shrimp): © Ken Lucas/Ardea London Limited; (snails): © Fred Whitehead/Animals Animals
Marine snails, at the base of salt
marsh cordgrass, feed on algae.
35.3 Aquatic Ecosystems
• Coastal Ecosystems
– Seashores
• Littoral zone - between high and low tidal
marks – divided into 3 zones
• Rocky or sandy beaches
– Animals must burrow on sandy beaches
• Clams, crabs, sand (ghost) shrimp,
sandhoppers
Seashores
35.3 Aquatic Ecosystems
• Oceans
– Ocean play a major role in redistributing heat in the biosphere
– Major influence on wind patterns
• Northern hemisphere – Currents circulate clockwise
• Gulf stream brings tropical Carribean water to east coast of North America and higher latitudes of western Europe
35.3 Aquatic Ecosystems
• Oceans
– Ocean currents influence climate
• Southern hemisphere – Currents circulate counterclockwise
• Humboldt Current: circulates cold, nutrient-rich water along west coast of South America
Upwelling: cold offshore winds cause nutrient-rich waters to rise and displace warm, nutrient-depleted water
35.3 Aquatic Ecosystems
• Oceans
– Pelagic Division (open waters)
• Neritic Province – sunlight and inorganic nutrients
– Coral reefs
• Oceanic Province – lacks nutrients
– Benthic Division (ocean floor)
• Sublittoral zone – continental shelf ex. seaweeds
• Bathyal zone – continental slope ex. Sea urchins
• Abyssal zone – abyssal plain ex. Sea cucumbers
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Neritic Province
Oceanic Province
Pelagic Division littoral zone high-tide mark
low-tide mark
120 m
1,200 m
3,000 m
4,000 m
abyssal plain
abyssal zone
bathypelagic zone
mesopelagic zone
epipelagic zone Benthic
Division
depth
(meters)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Me
so
pe
lag
ic Z
on
e
(12
0 –
1,2
00
m)
phytoplankton zooplankton
sea turtle
dolphin shark
jellyfish
ocean bonito
mackerel
squid
tuna
prawn
midshipman
viperfish
hagfish anglerfish
glass sponges
sea cucumber
brittle stars
gulper
barracuda
baleen whale
Ep
ipe
lag
ic Z
on
e
(0 –
12
0 m
)
Bath
yp
ela
gic
Zo
ne
(1,2
00
– 3
,00
0 m
)
Ab
ys
sa
l Z
on
e
(3,0
00
m –
bo
tto
m)
deep-sea
shrimp
tripod
fish
sperm
whale
giant
squid
lantern
fish