Transcript Slide 1

Chapter 6
Major Ecosystems of the World
Lecture Outline
► Terrestrial
Biomes
 Define Biome
 Representative terrestrial biomes (characteristics –
physical & biological)
 Human impacts on biomes
 Impact of altitude & latitude
► Aquatic
Ecosystems
 Environmental factors that affect ecosystems
 Representative aquatic ecosystems
 Human impacts on aquatic ecosystems
What is a biome?
►A
broad, regional type
of ecosystem that has
distinct climate and
soil conditions and a
distinctive kind of
biological community
adapted to those
conditions.
Biomes
► Include:
 Many interacting ecosystems
 Terrestrial ecology
►Community
to ecosytems to landscape to biome
 What is important in determining a biome –
Temperature and precipitation
 Also influenced by landforms (especially
mountains).
Major Biomes of World
Vertical Zonation
► Going
up a mountain is like traveling to the
poles
► What happens as you go up a mountain?
► Important differences between latitude and
elevation biomes
Tundra
(Arctic or Alpine Tundra)
► Location
– High
mountains or latitude
► Vegetation –treeless,
low vegetation
► Growing season - short
► Seasons – cold, harsh
winters, frost any
month.
► Water is locked up in
the snow and ice
Arctic Tundra
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Low productivity, low
diversity, low resilience
Permafrost – soil is frozen
year round
Vegetation – no deep
roots, small plants
Heave/settlement - due to
freeze & thaw
Climate – very cold, little
percipitation
Drainage – none, clayey
soils
Alpine Tundra
► Where
is this biome?
Located at high
altitudes
► How is it different from
Artic Tundra?
 More solar radiation
 Very hot temperatures
during day in summer
 Lots of wind & gravelly
soil
 Well draining
Tundra Fauna
► Year
round –
Lemmings, voles,
weasels, & artic foxes
► Migratory – Musk ox,
caribou, alpine
mountain goats,
mountain sheep, birds,
insects
Tundra Flora
► Dwarf
vegetation –
dwarf willows, dwarf
birches, sedges,
grasses, mosses,
lichens
► All very small
Human effects on Tundra
► Oil
and natural gas
wells – roads,
pipelines, drilling
locations
► Mineral excavation –
mining
► Climate Change –
melting permafrost,
warmer temperature.
Taiga
(Boreal forests, Conifer forests)
► Taiga
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Found in northern hemisphere only
On edge of artic tundra
Low productivity & low resilience
Peat formed by cold temperatures, very wet soil in
summer, acids from fallen needles
► Boreal
Forests
 Found between 45 & 60 degrees north latitude
 Moist & cool
 Many streams & wetlands
Taiga Flora & Fauna
► Taiga
Flora –
 Black & white spruce,
balsam fir, eastern
larch, aspen, & birch
► Taiga
Fauna –
 Caribou, wolves, bears,
moose, rodents,
rabbits, lynx, sable,
mink, migratory birds,
insects
Temperate Rain Forests
(Conifer Forests)
► Location
– NW North
America, SE Australia,
S. South America
► Precipitation – High;
condensation from
dense canopy
► Flora – Mosses, lichen,
& Ferns cover
branches
► Olympic National Park
Temperate Rain Forest
Flora & Fauna
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Flora –
 Large Evergreen trees –
western hemlock, douglas
fir, western red cedar
 Epiphytes – what the heck is
that? Mosses, orchids,
lichen, fern
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Fauna – squirrels, wood
rats, mule deer, elk, birds,
amphibians, reptiles
Human Impact Taiga, Boreal Forests &
Temperate Rainforest
► Logging
– increased
erosion, siltation of
rivers & creek
► Peat Mining – used as
an energy source, long
lasting damage
Temperate Deciduous Forest
(Broad-Leaved)
► Precipitation
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significant
► Key adaptation –
ability to produce
summer leaves that
are shed for winter
► Rich topsoil with
underlying clay
Temperate Deciduous Forest
Flora & Fauna
► Flora
– Oak, maple,
birch, beech, elm, ash,
small shrubs, flowers,
herbaceous plants
► Fauna – puma, wolves,
bison, deer, bear, and
many small animals
and birds
Grasslands (Prairies & Savannas)
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Location – dry continental
climates of Great Plains,
Russian Steppes, African
Savanna, South American
Pampas
Richest soil in world
Flora – few trees except
along rivers, grass
Wildfires - helps maintain
the grasslands.
Grassland Flora & Fauna
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Flora –
 Grasses both short and tall
 Herbaceous flowering plants
 Savannas - acacia
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Fauna
 Prairies – bison, wolves,
deer, elk, antelopes,
migratory birds
 Savannas – wildebeast,
antelope, giraffe, zebra,
elephants, lions, & hyenas.
Human Impact on Grasslands &
Savannas
► Agriculture
–
 90% of North American grassland has vanished
 Rarest biome in North America
► Rangeland
 Both North American grassland and African
savannas are being used for cattle
Chaparral
(Mediterranean, Thorn Shrub)
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Climate – warm, dry
summers & cool, moist
winters
Location – California,
Mediterranean Coast, SW
Australia, Central Chile,
South Africa
Covers small area
Highly desired for human
population – great climate
Drier areas – African
Sahel, northern Mexico,
Great Basin
Chaparral – Flora & Fauna
► Flora
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Varies around the world
Evergreen shrubs with small, leathery leaves
Scrub Oak, small trees,
Fire Resistant
► Fauna
–
 Mule deer, wood rats, chipmunks, lizards, birds
 Thorn shrub – snakes, lizards, rodents,
antelopes, gazelle, rhinos, giraffes
Human affects on Chaparral
► Preferred
location of
humans to live
► Crowding out the
indigenous flora &
fauna
Deserts
► Precipitation
–
infrequent &
unpredictable
► Location – 30 degrees
north & south latitude,
leeward side of rain
shadow
► High in mineral
content
Desert Flora & Fauna
► Flora
– Perennials,
annuals, cacti, yuccas,
Joshua trees, sage
brush
► Fauna – amphibians,
reptiles, rodents, mule
deer, jack rabbits,
kangaroo
Human impacts on Deserts
► War
► Development
into
agricultural areas
► Habitation
Tropical Rainforests
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Climate – warm all year
round, rains daily
Location – Equatorial
Regions
Soil – old, thin, acidic and
nutrient poor
Where are all the
nutrients? In the canopy of
the forest
Rapid decomposition and
recycling of dead organic
matter
Rainforests Flora & Fauna
► Flora
– flowering plants
 Three distinct stories of plants
► Tall
Trees
► Middle Story
► Lower Story
 Epiphytes, lianas
 1/3 to ½ of all species of plants & insects
► Fauna
 Reptiles, amphibians, birds, sloth’s, monkeys, elephants.
Human impacts on Rainforests
► Logging
–
 Agriculture – plants and livestock
 Wood harvesting – furniture, heat/cooking
► Mining
 Erosion
 Water contamination
► 1-1/2
acres are destroyed a second; some
scientist think we will lose them all in 40
years.
Aquatic Ecosystems
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Freshwater – rivers,
streams, lakes, ponds,
marshes, swamps
Estuaries – where rivers
meet oceans or seas
Marine
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Intertidal
Benthic
Neritic
Oceanic
Freshwater Ecosystems
► Vary
significantly
► Influenced by:
 Local Climate
 Soil
 Surrounding
Ecosystems
 Affects from upstream
Rivers and Streams
► Flowing
ecosystem
► Changes greatly from
source to mouth
► Groundwater can
intersect
► Depend on land for
energy - detritus
Rivers and streams
► Features
of a river
Flora & Fauna of Rivers & Streams
► Greatly
influenced by
surrounding terrestrial
ecosystems
► Varies widely
depending on velocity
of water, temperature,
water quality
Impact of Humans on Streams and
Rivers
► Pollution
► Dams
► Development
Lakes and Ponds
► Littoral
zone – most productive zone, where
photosynthesis is greatest,
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► Limnetic
Zone – open water beyond littoral
zone; extends down as far as light
penetrates. Microscopic organisms
► Profundal Zone – Beneath Limnetic zone,
shallow lakes don’t have, food drifts from
above.
Lake Zones
Thermal Stratification in Lakes
► Layering
in lakes determined by how much light
penetrates
► Thermal stratification:
 Summer sunlight penetrates water -> warms surface,
less dense
 Cool water stays on bottom, more dense
 Line that marks change in density is called a
thermocline
 In fall, surface water becomes colder than lower water
and the warmer water below rises (fall turnover)
 In spring, reverse happens after ice melts (spring
turnover)
Thermal Stratification in lakes
Marshes & Swamps
Wetlands
► Areas
covered by shallow water for part of
year (plants can grow in water)
► Soil rich in nutrients
► Grasslike plants dominate
► Swamps – wetlands with trees
► Marshes – wetlands without trees
► Bogs & Fens – areas without trees that
accumulate peat, low productivity
Estuaries
► Bays
or semi-enclosed
bodies of brackish
(salty but less than
seawater)
► Contain rich sediment
carried from upstream.
Marine Ecosytems
► Divided
zones:
into several
 Intertidal
 Benthic
 Pelagic
► Neritic
► Oceanic
Pelagic Environment
► Determined
by depth
of water
► Neritic province – area
from shoreline to
depth of 200 meters
Oceanic province – area
in open ocean with
water depths greater
than 200 meters
Intertidal Zone
► Shoreline
area that is
between low and high
tides
► High levels of light and
nutrients
► Abundant oxygen
► Highly productive but
stressful environment
Benthic Environment
► Ocean
floor
► Mostly sand and mud
► Zones:
 Abyssal benthic zone –
extends from 4000 to
6000 m
 Hadal zone – extends
deeper than 6000 m.
Flora of Marine Ecosystem
► Kelp
► Coral
Reefs – must
have light
► Sea Grasses – 95%
not eaten; instead
decomposed by
bacteria
Neritic Province
► Shallow
water close to shore
► Upper reaches comprise the euphotic zone:
 Extends to depth of 200 meters
 Enough light penetrates to support
photosynthesis
 Phytoplankton are producers, zooplankton are
primary consumers, nekton are secondary
consumers, carnivorous nekton are tertiary
consumers
Oceanic Provinces
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Largest marine
environment
Deep water organisms
feed on marine snow
(organic debris that floats
down from upper reaches)
Organisms adapt to dark
environment (called
aphiotic)
Many organisms can
produces own light
Human Impact on Marine
Environments
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Damage to coral reefs:
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High salinity
Pollution
Overfishing
Tourism
Global warming
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Pollution - Plastic
Development
Mining
Oil Drilling
Overfishing
Oceans