Transcript Earth`s Biomes

Earth’s Biomes
Content Standard 15: Identify
biomes based on environmental
factors & native organisms.
Earth’s Biomes
► All
organisms interact with living & nonliving
things in their environment.
► Because the environment is so complex, scientists
divide it into different regions. These regions are
determined largely by their abiotic factors.
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Soil composition
Amount of light, water & inorganic nutrients
Altitude (height above sea level)
Latitude (distance from the equator)
Climate (long-term weather pattern in an area, including
average high & low temperatures & amounts & types of
precipitation)
Biomes
► The
major ecosystems of Earth are called
biomes.
► A biome covers a wide area & is
characterized by specific physical conditions
& types of organisms.
► The 6 major biomes on land are
characterized by their climate, latitude,
altitude, & proximity to water, including
oceans, lakes & rivers.
Regardless of their actual location, similar biomes
around the globe have similar groups of organisms
that possess similar adaptations to the environment.
Biomes
► The
major terrestrial biomes are tundra,
deserts, tropical rain forests, grasslands,
taiga (coniferous forests), & temperate
deciduous forests.
► Each of these terrestrial biomes is
characterized by a set of abiotic factors & a
unique community of organisms.
► 2 key abiotic factors that define each biome
are its average annual amount of
precipitation & its temperature range over
the course of the year.
Average Yearly
Precipitation (in)
Yearly Temperature
Range (°F)
Tundra
6 - 10
-29 – 54
Desert
<10
28 – 120
Tropical Rain
Forest
>80
68 – 95
Grassland
20 - 35
-40 – 100
Taiga (Coniferous
Forest)
16 – 40
-22 – 86
Temperate
Deciduous Forest
30 – 60
-22 – 86
Biome
Terrestrial Biomes: Tundra
► The
tundra is a cold, dry biome that
receives an average of 15 to 25 cm (6 to 10
in) of precipitation (mostly snow or ice)
each year.
► The tundra is located in the Arctic &
Antarctic regions & at the tops of high
mountains in temperate zones.
► A defining feature of the tundra is
permafrost, a layer of permanently frozen
subsoil.
The Tundra Biome
Tundra
Vegetation
Terrestrial Biomes: Tundra
► Summers
are short & cool; winters are long,
cold, & usually dark.
► Tundra plants display stunted growth due to
the freezing of the topsoil, harsh winds,
cold, & a short growing season.
► Tundra animals include migratory birds,
musk oxen, Arctic foxes, & caribou.
► Many of these animals have fur that
changes from brown in summer to white in
winter to help them blend with their
surroundings & avoid predators.
Arctic Hare in Summer & Winter
Terrestrial Biome: Desert
► The
desert is characterized by very dry
conditions and less than 25 cm (10 in) of
precipitation each year.
► Desert soils are mineral rich but contain
little organic matter.
► Deserts can be hot, cold, or very variable in
their temperatures.
► Desert organisms are adapted to
temperature extremes & to temperatures
that may vary by more than 19°C (66°F) on
a daily basis.
Deserts are located in Africa, Asia, the
Middle East, North & South America, &
Antarctica.
Terrestrial Biome: Desert
► Most
desert plants are adapted for storing
water.
► Snakes, lizards, jackrabbits, & rodents are
common animals in hot deserts.
► Many of these are active only at night when
temperatures are cooler. Some burrow into
the ground during daylight hours to escape
the hot sun.
Terrestrial Biome: Tropical Rain
Forest
► The
tropical rain forest has greater
biodiversity than all other terrestrial biomes
combined.
► A tropical rain forest is characterized by
nutrient-poor soils, warm year-round
temperatures, & average yearly
precipitation of 200 to 400 cm (80 to 160
inches) in the form of rain or mist.
Terrestrial Biome: Tropical Rain
Forest
► Trees
in the tropical
rain forest are very tall
& form a dense
covering called the
canopy that shades the
lower layers.
Tropical rain forests are located near the equator in
South & Central America, southeastern Asia, Africa,
southern India, & northern Australia.
Terrestrial Biomes: Grasslands
► Grasslands
have warm to hot summers &
cool to cold winters & receive 50 to 90 cm
(20 to 35 in) of precipitation each year.
► Precipitation in this biome is seasonal,
occurring mostly in the spring & fall.
► Soils are rich in nutrients & organic matter.
Much of this organic matter is found in a
thick layer of topsoil located at the soil
surface.
Grasslands are located in central Asia, N.
America, Australia, central Europe,
Africa, & S. America.
Terrestrial Biomes: Grasslands
► Plants
include numerous grasses & herbs.
► Animals include coyotes, badgers, mule
deer, rabbits, prairie dogs, bison, & many
birds & insects.
Terrestrial Biomes: Temperate
Deciduous Forests
► Temperate
deciduous forests are
characterized by broad-leafed trees that
shed their leaves in the fall & sprout them in
the spring.
► Rainfall & temperatures are moderate. This
causes rapid decomposition of organic
matter.
► This results in soil that is rich in both
nutrients & organic matter.
Deciduous forests are located in N.
America, Europe & Asia.
Typical animals of these regions include foxes,
squirrels, raccoons, deer, turtles, a wide variety of
birds, and insects. Fungi are also common in this
biome.
Terrestrial Biomes: Taiga
► The
taiga is a cold to cool, moderately wet
biome that is located in the northern parts
of N. America, Europe, & Asia.
Terrestrial Biomes: Taiga
► The
taiga is sometimes called the coniferous
forest biome because of the cone-bearing
(coniferous) trees that cover its landscape.
► Soils in the taiga tend to be acidic.
► In addition to coniferous trees, mosses
thrive in the acidic soil of this biome.
Typical animals of this biome include black
bears, moose, elk, deer, wolves, squirrels,
and a variety of insects.
Terrestrial Biomes: Wetlands
►A
wetland is a land ecosystem in which
water covers the soil or is present near the
soil surface for at least part of the year.
► Wetlands are a cross between a terrestrial
ecosystem & an aquatic ecosystem & can
have either moving or standing water.
► Wetlands serve as breeding grounds for
many species of birds, fish, amphibians,
insects, & other animals.
Terrestrial Biomes: Wetlands
► Freshwater
wetlands include bogs, swamps,
& marshes.
► In addition to providing habitat for many
species, wetlands serve an important role in
helping to cleanse & purify water that
moves through the environment.
Aquatic Biomes
► Aquatic
ecosystems are defined by their
salinity, chemistry, depth, flow, & water
temperature.
► Salinity is used to divide aquatic biomes into
2 large groups: freshwater biomes & marine
biomes.
► As its name implies, a freshwater biome is
an aquatic ecosystem whose primary
feature is freshwater. The marine biome is
an aquatic biome whose main feature is salt
water.
Aquatic Biomes: Freshwater
► Two
main types of freshwater biomes are flowingwater ecosystems & standing-water ecosystems.
► Flowing-water ecosystems include rivers, streams,
creeks, & brooks.
► Organisms that live in these ecosystems are adapted
to seasonal changes in water level & rate of flow.
► Standing-water ecosystems include lakes & ponds.
► Water generally flows into & out of these ecosystems
& circulates within them.
► The standing water of these ecosystem provides
habitat for many different organisms.
Aquatic Biomes: Marine
► Marine
biomes are defined by water that is
high in salt content. They vary in their
distance from the shore & in the depth of
the water.
► Unique communities of organisms, such as
the intertidal organisms found on beaches,
live at the edges of marine ecosystems.
► Water depth affects pressure & the amount
of light that penetrates the water.
Moving from the shore toward the open ocean,
marine ecosystems include the intertidal zone, the
coastal (neritic ocean), and the open ocean.
Aquatic Biomes: Marine
► Organisms
that live in the intertidal zone are
directly affected by the twice-daily rise & fall
of the tide.
► Sometimes they are completely submerged
in water; at other times they are exposed to
the air & sunlight.
Aquatic Biomes: Marine
► Organisms
in the coastal ocean live on the
shallow shelf that extends from the low-tide
line to the deep ocean.
► This region is known as the neritic zone.
► The neritic zone is shallow enough to allow
sunlight to penetrate its water & reach the
ocean bottom.
► The region is also shallow enough to keep
the water pressure moderate.
Aquatic Biomes: Marine
► Coral
reefs & kelp forests thrive in the
neritic zone. These areas provide abundant
resources such as food & shelter for other
ocean-dwelling organisms. Most aquatic life
lives in this ocean region.
Aquatic Biomes: Marine
► The
deep ocean lies beyond the coastal
shelves of the continents.
► The deep ocean covers about 60% of
Earth’s surface.
► Although it covers the largest area, the
deep ocean actually serves as home to the
fewest ocean species.
► Organisms that live in the deepest parts of
this region need to be adapted to a cold,
dark, & extremely high-pressure
environment.
Estuaries
► Estuaries
are areas where freshwater meets the
salty water of the sea.
► Estuaries contain brackish water—a mixture of
freshwater & salt water.
► The concentration of salt in water can change
frequently because of variations in rainfall,
changes in ocean conditions such as waves, tides,
& currents, & wind.
► Estuaries also have constantly changing water
levels that are affected by the rise & fall of the
ocean tides.
► 2 ecosystems that form in estuaries are salt
marshes & mangrove swamps.
Salt Marsh
Mangrove Swamp
Which terrestrial biome is
characterized by permafrost?
A.
B.
C.
D.
River
Desert
Tundra
Tropical Rain Forest
Which biome receives very little rainfall
throughout the year & includes snakes,
lizards, & jackrabbits as its characteristic
animal species?
A.
B.
C.
D.
Desert
Temperate Deciduous Forest
Taiga
Tundra
What is the correct arrangement of
ocean zones moving away from the
shoreline?
A.
B.
C.
D.
Benthic Zone → Neritic Zone → Intertidal Zone → Open Ocean
Intertidal Zone → Open Ocean → Coastal Zone
Intertidal Zone → Neritic Zone → Open Ocean
Neritic Zone → Open Ocean → Intertidal Zone
Which of these is a freshwater
biome?
A.
B.
C.
D.
Tundra
Estuary
Ocean
River
What land biome has the greatest
variety of life?
A.
B.
C.
D.
Tropical Rain Forest
Desert
Tundra
Grassland
PowerPoint adapted
from the Standard 15
(Lesson 20) lesson in
the Coach book.
Alabama AHSGE Coach, Biology
Triumph Learning, 2009