Transcript Temperate Grassland

Weather, Climate and Biomes
WEATHER & CLIMATE
Weather (troposphere) short
term occurrences at a
particular place and time
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 Troposphere = 78% N2; 21% O2; 1% Argon, CO2 and trace gases
 99% of the mass of the atmosphere is in the troposphere + stratosphere
 Stratosphere = contains atmospheric ozone (absorbs UV radiation)
Climate (troposphere) a
region’s long term, general
pattern of weather
conditions
ABIOTIC FACTORS OF WEATHER
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Temperature
Precipitation (rain, snow, sleet, hail)
Humidity
Pressure
Cloud Cover
UV Radiation
Wind
Warm Fronts – low pressure; less dense; raises over air masses (cloudy skies & drizzle)
Cold Fronts – high pressure; dense; pushes in under warm air (thunderstorms & then clear
skies & nice weather
Topographic Features Influence Weather Patterns
RAIN SHADOW EFFECT!
Prevailing winds pick up
moisture from an ocean.
Windward Side of Mountain – high
precipitation & forested area
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.
Leeward Side of Mountain – low precipitation
& arid to semi-arid conditions (deserts)
LOCATION, LOCATION, LOCATION
Global Air Circulation
and Biomes
Tundra
Deciduous Forest
Savanna
Taiga
Chaparral
Rainforest
Grasslands
Desert
Alpine
Desert-scrub
Biomes
Climatograph
Mountains
• Steep or high lands which cover about ¼ of the
earth’s land surface
• They are not a biome but they have dramatic
impacts on our ecosystems
– They contain the majority of the world’s forests
– Provide a habitat for endemic species that are found no
where else in the world
• Serve as a sanctuary for animal species driven to migrate
from lowland areas to higher altitudes
– Help to regulate earth’s climate due to snow and ice
reflecting solar radiation back into space
– Melting mountain-top snowpack provide surface water
in streams for use by animals
Human Impacts
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Agriculture
Timber extraction
Mineral extraction
Increasing tourism
Urban air pollution
Increased ultraviolet radiation from ozone
depletion
• Soil damage from off-road vehicles
Types of Forest
Tropical Rain Forests
Temperate Deciduous Forests
Taigas (Boreal Forests)
• Dominated by trees
• Areas of high productivity and biodiversity
Tropical Rain Forest
• Typically found along
the equator
• Also found 30oN to 30oS
from the equator
• Brazil, Central America,
Indonesia, Central
Africa
• 20oC – 30oC
• >200 cm rainfall
Fig. 7-15a, p. 154
Characteristics
• Year round consistently warm temperatures,
high humidity, and heavy rainfall
• Dominated by broadleaf evergreen plants
• High primary productivity and biodiversity
• Importance:
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Recycling of CO2
Release of O2
Biodiversity
Medicinal Purposes
Distinct strata (zones) such as canopy, emergent, understory,
shrub, & forest floor, provide habitat space for the abundant
life
Soil is old, thin, acidic; nutrient poor because most nutrients
are in the biomass
Plant Adaptations
• Have thin, smooth bark
• Climbing vine and other plants grow on
rainforest trees, climbing into the canopy
so its leaves get more sunlight
• The leaves are big, thick and waxy, and
have 'drip tips' to let the rain drain off
quickly
• Some tropical rainforest plants are
carnivorous, or meat-eating
• Thousands of flowering plants grow onto
trees so they get sunshine. Their roots are
not in soil, and the plants get their food
from air and water.
Animal
Adaptations
• They are adapted to eating a specific plant or animal that
few others eat.
• Since the rain forest has many trees, animals are able to
climb and forage for food in trees (monkeys and sloths)
• They are able to swim and cope with a lot of rainfall
(caimans, turtles and snakes)
• Some are nocturnal to avoid the high temperatures of the
day and the competition from diurnal animals (bats)
• Some have developed camouflaging mechanisms
Major Human Interferences
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Agriculture
Timber harvest
Livestock grazing
Some mineral mining
Temperate Deciduous Forests
• Found between 30o and
60o north and south
latitudes
• Eastern United States,
most of Europe
• 0oC – 20oC mild climate
• 75 to 150 cm rainfall
Fig. 7-15b, p. 154
Characteristics
• Moderate temperatures that fluctuate with
seasons, four distinct season
• Five layers to the forest: Tree stratum (oak,
beech, maple); Sapling Zone; Shrub
(rohodendrons, azalea); Herbal; Ground
(moss, lichen)
• Trees go dormant in the winter by dropping
their leaves in the fall
• Soil: high nutrients due to deciduous trees,
lots of humus and leaf litter
Plant Adaptations
• SUMMER: their broad green leaves to
capture sunlight needed to make food
through photosynthesis.
• As temperatures drop, the tree cuts off
the supply of water to the leaves and
seals off the area between the leaf stem
and the tree trunk.
• With limited sunlight and water, they
change colors
• WINTER: they loose the leaves since
they cannot protect them.
– Losing their leaves helps trees to conserve
water loss through transpiration.
Animal Characteristics
• Organisms are mostly dark in
coloration to blend in with the
environment
• Animals hibernate
• Some migrate to warmer climates
during the winter
• Some store food for the winter
Major Human Interference
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Logging
Agriculture
Tree farms
Urbanization
Taigas (Boreal Forests)
• Found just south of
the arctic tundra in
northern regions of
North America
(Canada), Asia and
Europe
• -5oC – 15oC
• less than 50 to 150
cm rainfall
Fig. 7-15c, p. 154
Characteristics
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Taiga is the largest biome on earth
Winters are long, dry, and extremely cold
Plant diversity is low
Acidic soils, lots of litter but slow
composition
Plant Adaptations
• Few species of conifers
– Pine
– Hemlock
– Cedar
– Spruce
• Shed snow easily, and retain their
needles through the winter.
• The needles are adapted, with
thick waxy coatings and small
surface area, to resist cold
conditions and minimize water loss
Animal Adaptations
• large paws (for running over the snow)
• white fur (to blend in)
• may burrow beneath the snow and
forage for their food in tunnels on and in
the forest floor; they are insulated from
the worst cold of winter by the snow.
• Others hibernate during the winter.
• Some bird species deal with the cold by
migrating south during the cold winter
and returning in the spring
Major Human Interference
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Logging
Mining
Fur trade
Dams
Types of Grasslands
Tropical Grassland (Savannas)
Temperate Grassland (tall and short grass prairies)
Cold Grasslands (artic tundra)
• Exists in areas where there is too much moisture for
desert
biomes and too little moisture for forest biomes
• Regulated by seasonal drought, occasional fires, and the
grazing of herbivores
• Found in the interior of continents
Tropical Grassland (Savannas)
• Largely found in
Eastern Africa
• Also parts of South
America and Australia
• 8oC – 20oC
• 50 – 150 cm rainfall
Fig. 7-12a, p. 151
Characteristics
• Warm temperatures and alternating warm and dry
seasons (will experience several months of little/no rain
fall)
• Large grazing herbivores such as gazelles, zebras,
wildebeests
• Plants have deep roots to utilize groundwater supplies
• Soil: low in minerals, easily leached, may have high
levels of aluminum
Major Human Interferences
• Livestock grazing
• Agriculture
• Poaching
Temperate Grasslands
• Location:
– Prairies: mid-western and
western United States and
Canada
– Pampas: South America
– Steppes: Russia
– Veld: South Africa
• -5oC – 10oC
• 25 – 100 cm rainfall
Fig. 7-12b, p. 151
Characteristics
• Rainfall determines whether it is a tall-grass or a
short-grass prairie (tall-grass prairies receive
almost three times as much rain as short-grass)
• Winters are cold, summers are hot and dry
• As grasses die and decompose annually, large
amounts of organic matter accumulates in the
soil, making this area high productive for crops
• High winds and rapid evaporation promotes fires
in the summer and fall that eliminates other
competing species
Major Human Interferences
• Agriculture
• Livestock grazing if too dry for crops
Cold Grasslands (Artic Tundra)
• Located between 55°
and 70° Northern
Latitude.
• In other words, they
extend mostly in the
top portion of the
Northern Hemisphere.
• -20oC to 10oC
• <10 cm rainfall
Fig. 7-12c, p. 151
Characteristics
• Frigid, treeless plains that are covered with
snow and ice much of the year
• Extreme cold forms permafrost –
underground soil in which captured water
stays frozen for more than two consecutive
years
• Low biodiversity
• Short season of growth and reproduction
• Soils thin; soils very young; nutrient poor –
since there is little organic litter
Major Human Interferences
• Too cold for much human activity
• Oil/natural gas drilling and associated
transport issues
• Global warming which is melting
permafrost in summer
Grassland Plant Adaptations
• During dry periods grasses can become dormant, leaving
only dry stems and seed heads standing above the roots.
When rain falls, new shoots come up from the roots again.
• Some grasses are annuals, and survive the winters as seeds
• Other species are perennials, and sprout again each year
from a well-developed network of roots.
• Another adaptive characteristic of grasses is that they grow
up from where the stems join the roots.
– This allows animals to eat grass without slowing its growth, and
people to mow lawns without killing the grass
Grassland Animal Adaptations
• Migration is one of the most prominent adaptations.
– Several animal species which inhabit the Savannah migrate
thousands of miles in search of food and water during a particular
time of the year.
• have broad and flat-topped teeth which makes it easy for
them to feed on grass.
• The small animals seek shelter by burrowing in the ground.
– the front feet of these animals are armed with sharp claws
• Adapted to withstand the extreme climatic conditions,
characterized by hot summers and cold winters
• Specially developed digestive system for herbivores
• The ability of these animals to camouflage
Types of Desert
Tropical Deserts
Temperate Deserts
Cold Deserts
• Occurs in continent interiors where little precipitation is often
distributed unevenly throughout the year; < 30 cm
• Experience intense heat and evaporation during the day and
cooler nights due to rapid heat loss from the little vegetation
available to help radiate the heat more slowly
• Temperature depends on location, deserts usually at 30oN or 30oS
of equator or interior of continents due to rain shadow effect; -5
to 30o C
• Soil
Tropical Deserts
• Cover much of northern
Africa (the Sahara)
• Parts of the Middle East
(Saudi Arabia)
Fig. 7-11a, p. 149
Characteristics
• Surface areas have little vegetation and are
dominated by rocks and sand that are
often blown about by frequent windstorms
• Extremely high daytime temperatures
Temperate Deserts
• Found in southwestern
United States (Mojave
and Sonoran deserts)
Fig. 7-11b, p. 149
Characteristics
• Receive more precipitation than tropical
deserts
• Characterized by patchy drought-resistant
plants
• Have high daytime and low nighttime
temperatures
Cold Deserts
• Areas of the United
States known as the
Great Basin (Idaho,
Utah)
• Gobi desert in northern
China and southern
Mongolia
Fig. 7-11c, p. 149
Characteristics
• Vegetation is very sparse
• Winters are extremely cold
Desert Plant Adaptations
• Reduction of leaves, often into spines. Reduces surface
area for water loss.
• Development of the stem as a photosynthetic structure
• Water storage in the stem
• Development of defense structures. (spines and chemical
defenses).
• Coating the plant with a thick waxy cuticle to prevent
water loss.
• A dense coating of hairs, decreases evaporation.
• Extensive underground root systems. These roots can
grow straight down to groundwater, or spread out to take
advantage of short, intermittent rains.
Desert Animal Adaptations
• A nocturnal lifestyle, which keeps them out of
the heat of day
• Living in burrows, which are cooler and more
humid.
• Slender bodies with long limbs - better for
shedding heat.
• Adaptations for reducing water loss specialized snouts, waxy body coatings, efficient
kidneys, etc.
• Some get all their water from the food they eat.
• Eyes protected from the sun. Long eyelashes or
deep-set eyes
Major Human Interference
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Off-road vehicles
Overgrazing
Urbanization
Oil drilling
Mining
The Chaparral (Temperate Shrubland)
• Considered to be a minor biome
• Found along coastal areas
• Between 30 and 40 degrees
north of the equator
– Southern California
– Mediterranean Sea
• between 30 and 40 degrees
south of the equator
– Central Chile
– South Africa
– Australia
•0oC – 38oC
•40 – 60 cm rainfall
Fig. 7-14, p. 152
Characteristics
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Characterized by scrub vegetation
3 seasons: fall, spring and drought
Mild Winters; HOT Summers
Soil: shallow, rocky, nutrient poor
Chaparral Plant Adaptations
• Chaparral plants employ four different
strategies in response to drought.
– Avoiders (avoid drought with long roots and
hard/thick leaves)
– Persisters (tolerate drought by physiological
adaptations and movements)
– Retreaters (annuals or underground storage
organs)
– Chameleons (evade drought by being semisummer deciduous)
Chaparral Animal Adaptations
• Animals do not require much water.
• Nocturnal and are usually small.
• Have adapted to this sparse and rough terrain by
becoming agile climbers, foraging over larger areas
and varying their diet to include the often scrubby
brush lands.
Major Human Interference
• Urbanization
• Fires lead to flooding