Land Biomes of the World

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• Land Biomes of the World
• Mrs. Hartges Science Class

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The biosphere is the total of all of Earth's
ecosystems
THE BIOSPHERE

• The global ecosystem is called the biosphere
• It is the sum of all the Earth's ecosystems
• The biosphere is the most complex level in
  ecology

Figure 34.2A
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• The biosphere is self-contained

• except for energy obtained from the sun and heat
  lost to space
• Each habitat has a unique community of species

Figure 34.2B
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Abiotic FactorsAbiotic factors are those
non-living physical and chemical factors which
affect the ability of organisms to survive and
reproduce.   
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• Abiotic Factors
• Abiotic factors vary in the environment and
  determining the types and numbers of organisms
  that exist in that environment.
• light intensity
• temperature range
• type of soil or rock
• pH level (acidity or alkalinity)
• water availability
• dissolved gases
• level of pollutant

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Physical and chemical factors influence life in
the biosphere

• The most important abiotic factors that determine
  the biosphere's structure and dynamics include
• solar energy
• water
• temperature

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• Disturbances such as fires, hurricanes, and
  volcanic eruptions are also abiotic factors

Figure 34.4
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Biotic Factors

• Biotic factors are all the living things or
  their materials that directly or indirectly
  affect an organism in its environment.   This
  would include organisms, their presence, parts,
  interaction, and wastes.  Factors such as
  parasitism, disease, and predation (one animal
  eating another) would also be classified as
  biotic factors.

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Organisms are adapted to abiotic and biotic
factors by natural selection

• The presence and success of a species in a
  particular place depends upon its ability to
  adapt
• Natural selection adapts organisms to abiotic
  and biotic factors
• Biotic factors include predation and competition

Figure 34.5
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Regional climate influences the distribution of
biological communities

• Climate often determines the distribution of
  communities
• Earth's global climate patterns are largely
  determined by the input of solar energy and the
  planet's movement in space

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• Most climatic variations are due to the uneven
  heating of Earth's surface

• This is a result of the variation in solar
  radiation at different latitudes

North Pole
60º N
Low angle ofincoming sunlight
30º N
Tropic ofCancer
Sunlight directlyoverhead
0º (equator)
Tropic ofCapricorn
30º S
Low angle ofincoming sunlight
60º S
Figure 34.6A
Atmosphere
South Pole
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• The seasons of the year result from the permanent
  tilt of the plant on its axis as it orbits the sun

MARCH EQUINOX(equator facessun directly)
JUNE SOLSTICE(NorthernHemisphere tiltstoward
sun)
DECEMBERSOLSTICE(NorthernHemisphere tiltsaway
from sun)
SEPTEMBEREQUINOX
Figure 34.6B
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What is a Biome?

• Plants and animals don't live in isolation, but
  they live together with other plants and animals
  in an interdependent group called an ecological
  community. If you think about it for a moment,
  you will realize that all of the plants and
  animals in a particular ecological community must
  be adapted to the same climate so that they can
  all live in the same location.

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• A distinct ecological community of plants and
  animals living together in a particular climate
  is called a "biome." Scientists have divided the
  broad spectrum of climates and ecological
  communities found on Earth into biomes in
  different ways - some with many divisions, some
  with only a few.

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• Major terrestrial biomes

30º N
Equator
30º S
Tropical forest
Polar and high-mountain ice
Temperate deciduous forest
Savanna
Chaparral
Coniferous forest
Desert
Temperate grassland
Tundra (arctic and alpine)
Figure 34.9
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Tropical forests cluster near the equator

• Several types of tropical forests occur in the
  warm, moist belt along the equator Tropical
  Rainforest

Figure 34.10
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Savannas are grasslands with scattered trees

• Drier, tropical areas and some nontropical areas
  are characterized by the savanna Tropical Savannah

Figure 34.12
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Deserts are defined by their dryness

• Deserts are the driest of all terrestrial biomes
• They are characterized by low and unpredictable
  rainfall Desert

• Desertification is a significant environmental
  problem

Figure 34.13
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Temperate grasslands include the North American
prairie

• Temperate grasslands are found in the interiors
  of the continents, where winters are cold
• Drought, fires, and grazing animals prevent trees
  from growing
• Farms have replaced most of North America's
  temperate grasslands

Figure 34.15
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Deciduous trees dominate temperate forests

• Temperate deciduous forests grow where there is
  sufficient moisture to support the growth of
  large trees Deciduous Forest
• Nearly all of the original deciduous forests
  in North America have been drastically altered
  by agriculture and urban development

Figure 34.16
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Coniferous forests are often dominated by a few
species of trees

• The northern coniferous forest, or taiga, is
  the largest terrestrial biome on Earth Taiga

Figure 34.17
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• The taiga is characterized by long, cold winters
  and short, wet summers

• Coastal coniferous forests of the Pacific
  Northwest are actually temperate rain forests

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Long, bitter-cold winters characterize the tundra

• The arctic tundra lies between the taiga and the
  permanently frozen polar regions Arctic Tundra
• It is a treeless biome characterized by
  extreme cold, wind, and permafrost
• Permafrost is continuously frozen subsoil

Figure 34.18