Introduction to ENERGY FLOW

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Introduction to ENERGY FLOW

• FOOD CHAINS
• WEBS

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sun eclipse with palm

• the ultimate energy source

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Energy Flow in Ecosystems

• Energy flows from where into the biological world?

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Energy Flow

• How does the suns energy enter the biological
  world?

• What is photosynthesis?

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Energy Flow

• The suns energy flows into organisms that can
  change the sunlight into food then into organisms
  that eat them.
• This flow is

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PRODUCERS

• What are producers?
• Autotrophs that trap solar energy into organic
  molecules during photosynthesis can produce
  their own food
• Ex. Plants, algae and some bacteria

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CONSUMERS

• What are consumers?
• Heterotrophs that eat other organisms to obtain
  energy

• Examples deer, rabbits, cows, mice, lions,
  humans, hawks, snakes

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HERBIVORES

• What are herbivores?
• Organisms that eat plants

• Primary Consumers
• Ex. Cows, caterpillars, bunnies

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CARNIVORES

• What are carnivores?
• Organisms that eat meat (other animals/consumers)

• Secondary Consumers
• Ex. tigers, wolves, snakes, hawks

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TOP CARNIVORES

• What is a top carnivore?
• Top carnivores eat secondary consumers usually
  nothing feeds on them

• Ex. killer whale eating a sea lion or hawk eating
  a snake.

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OMNIVORES

• What are omnivores?
• Consumers that eat both plants and animals

• Secondary Consumers
• Ex. bears and humans

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Decomposers

• Why would they be called the environmental
  recyclers?
• They decompose excrement, dead bodies and leaf
  litter, returning

• nutrients to the physical environment.

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Energy Flow

• The series of steps in which organisms transfer
  energy by eating and being eaten is called a
• Food Chain

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Food Chains Food Webs

• The steps in the transfer energy from organism to
  organism in feeding relationships are called
• Trophic Levels.
• How does a food chain describe this path of
  energy? (arrows)

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Food Chains Food Webs

• Name the number of the trophic levels in the food
  chain below.
• How do the trophic level numbers correspond with
  the eating terms?

Trophic Level
1
2
3
4
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Food Chains Food Webs

• What important energy transfer is not shown in a
  food chain?
• Why is it that some energy is lost from one level
  to the next level?
• How much energy is actually passed on to the next
  level? (rule of thumb)

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Food Chains Food Webs

• What vital recycler is not shown in this food
  chain?

• Upon which organism(s) would it feed?

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Food Chains Food Webs

• Most organisms feed on more than one trophic
  level and feed on several different species at
  each trophic level. This is a food web.

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Arctic Food Web
http//www.arctic.noaa.gov/essay_krembsdeming.html
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Rangeland Prairie Food Web
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Introduction to ENERGY FLOW

• PYRAMIDS

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Ecological Pyramids

• Instead of representing trophic levels in a food
  web, an ecological pyramid can be used.

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Ecological Pyramids

• What do the big numbers represent?
• What does the kcal mean?

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Pyramid of Energy

• What happens to the energy as you go up?

• How much energy is available for the next level?
• What rule is this?
• What happens to the rest of the energy?

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Ecological Pyramids

• How is this pyramid different from the previous
  ones?

• What could the multiple pictures of the species
  at each level represent?

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Pyramid of Numbers

• What information would this pyramid include if it
  were a pyramid of numbers?

• How do they get a number total for a population
  of organisms?

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Pyramid of Biomass

• What information would this pyramid include if it
  were a pyramid of biomass?

• What is biomass?
• How do they get a number total for the biomass of
  a population?

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Ecological Pyramids

• Why is a pyramid used to represent these feeding
  relationships?

• How is this also a pyramid?
• Explain what happens to the mass, numbers,and
  energy from trophic level to trophic level.

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Ecological Pyramids

• What is different about this pyramid?
• How can the producer level be so small and
  support the trophic levels above it?

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Pyramids of Aquatic Ecosystems

• Numbers
• Biomass
• Energy

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Pyramids of Temperate Forests

• Numbers
• Biomass
• Energy

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Ultimate Predator?

• Why is man sometimes called the Ultimate
  Predator?

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Biomagnification
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Biomagnification

• Concentration of toxins increase as a toxin moves
  up the food chain.

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NUTRIENT CYCLES

• Energy flows and is constantly entering the
  ecosystem. Why? Nutrients must be recycled.
  Why?