Energy Flow thru Ecosystems

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Energy Flow thru Ecosystems

• Without the Sun there would be no life on earth.

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Energy Facts

• The sun is the major supplier of the earths
  energy.
• Yet only 0.1 of the suns energy is used by
  living organisms.
• Plants use 1/2 of the energy they receive and
  store the other as organic compounds.
• Energy cannot be recycled, it flows through the
  ecosystem.
• Most of the energy released is lost in the form
  of heat.

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• The amount of solar energy collected by all
  producers in an ecosystem is called primary
  productivity.
• Which ecosystem do you suppose has the highest
  primary productivity desert, forest, swamp,
  tundra, grassland?

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Actually, even the energy of a campfire comes
from the sun. How?
Sun ? Photosynthesis ? Wood ? Campfire
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Even the energy from a hydroelectric dam comes
from the sun. How?
Sun ? water evaporates ? rain ? river ?
hydroelectric dam
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Even the energy captured by a windmill comes,
from the sun. How?
Sun ? unequal heating ? winds ? windmill
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More about Energy Flow

• Decomposers are organisms that obtain there
  energy from dead organic matter.
• Organism eat organism at different levels.
• These levels are called trophic levels (feeding
  level).
• Ecosystems are made of many trophic levels.
• The amount of useable energy that is transferred
  from trophic level to trophic level is approx.
  10.

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Energy Pyramids (Trophic Levels)

• The lowest trophic level of the pyramid
  represents the producers and contains the most
  energy.
• The second level represents the primary
  consumers, also called 1st order. A 90 decrease
  in useable energy
• The third level or secondary consumers will have
  10 of the energy from the level below to use.

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Thinking time.

• All first order consumers are also called what?

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Lets Practice

• How many trophic levels are present?
• 5
• Determine the amount of useable energy for the
  different trophic levels.
• Level 2 36 J
• Level 3 3.6 J
• Level 4 0.36 J
• Level 5 0.036 J

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Pyramid of Numbers

• Carnivore populations are smaller in comparison
  to the rest of the ecosystem.
• They require more food to sustain their lives
  than the lower organisms.

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Carnivores
200
Carnivores
100,000
Herbivores
200,000
Producers
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Food Chain

• The simplest feeding arrangement in an ecosystem.
• Producers (autotrophs) are always at the base of
  the chain.
• The food chain may vary in length.
• Example Grass - cow - Human.
• Ex. plankton insect minnow small fish
  large fish - osprey

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Food Webs

• Many food chains interacting with each other.
• The arrow always points away from the organism
  being eaten to the organism doing the eating.
• Shows the movement of energy and matter in an
  ecosystem.

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Nutrient Cycles

• The suns energy drives most nutrient cycles.
• Much of the earths chemical nutrients are tied
  up in many life forms.
• The earths nutrients are finite, so they must be
  recycled.
• Examples Hydrologic, Carbon dioxide, and
  Nitrogen Cycles.

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Hydrologic Cycle

• Key terms
• Evaporation Liquid water changing state to a
  gas.
• Condensation Gaseous water changing state to a
  liquid
• Precipitation Water dropping from the sky.
• Transpiration Loss of water from plants.
• Run off Water not being absorbed into the
  ground.
• Ground water. Water found under ground

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Carbon Cycle

• Key Terms
• Photosynthesis Autotrophs capture the suns
  energy in organic compounds.
• Respiration Organisms releasing the stored
  energy from organic compounds.
• Combustion Burning of organic compounds.
• Carbonic Acid An acid formed from carbon dioxide
  and water.
• Calcium Carbonate Chemical found making up bone
  and shells.

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Nitrogen cycle

• Plant and animal wastes decompose, adding
  nitrogen to the soil.
• Bacteria in the soil convert those forms of
  nitrogen into forms plants can use.
• Rain storms contribute atmospheric nitrogen (78)
  through rain drops that reach the soil.
• Legumes, such as soybeans, alfalfa and clovers,
  are plants that can convert atmospheric nitrogen
  into plant-usable nitrogen.
• Factories that produce nitrogen fertilizers add
  nitrogen to the soil when farmers and gardeners
  "feed" their crops.

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The Flow of Energy

• Since plants capture the suns energy and store
  it in food, they are said to be producers.
• The amount of solar energy collected by all
  producers in an ecosystem is called primary
  productivity.
• Animals that receive their energy directly from
  plants are called primary consumers (herbivores).
• Consumers that feed on primary consumers are
  called secondary consumers (carnivores).
• Energy flows from the sun to the producer, then
  to the primary consumer, then to the secondary
  consumer, etc.

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Review

• Producers -
• capture the suns energy and store it in
  food.
• Primary Productivity -
• amount of solar energy collected by all
  producers in an ecosystem
• Primary Consumer
• animals that receive their energy directly
  from plants
• Secondary Consumers
• Consumers that feed on primary consumers