Energy Flow Through an Ecosystem Levels of Ecological

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Energy Flow Through an Ecosystem
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• Levels of Ecological Organization
• Energy flows through these levels

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Levels of Organization

• Species similar organisms that can produce
  fertile offspring.

• Populations individuals that are of the same
  species and live together

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• Communities Different populations that live
  together in an area
• Ecosystems All the biotic and abiotic factors
  of an area.

Give an example of a population, community and
ecosystem at ETHS
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Energy Flow Through an Ecosystem

• Thermodynamics the study of energy
  transformations
• Law 1 Energy can be transferred and changed but
  it CANNOT be created nor destroyed.
• Energy only flows through an ecosystem in one
  direction, from the sun or inorganic compounds to
  autotrophs (producers) and then to various
  heterotrophs (consumers)
• Sunlight is the main energy source for life on
  Earth
• Inorganic compounds (minerals) can also be energy
  sources (deep ocean)

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• Trophic Level classification of an organism
  based on their source of energy
• Energy flows through the different levels of an
  ecosystem

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1st Trophic Level-- Producers

• Can harness energy directly from their physical
  environment (sun)
• Transform this energy into chemical energy
• used as food, combine or break down molecules,
  make cells
• Called autotrophs because they can make their own
  food
• Examples plants, bacteria and some algae

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2nd Trophic Level -- Consumers

• Organisms that rely on other organisms for
  chemical energy
• Cannot harness energy directly from their
  physical environment
• Called heterotrophs because they cannot make
  their own food
• Examples animals, fungi, many bacteria
• Q Do all consumers eat the same thing?

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Herbivores

• Energy source comes from eating only producers
• Also called primary consumers
• Examples cows, caterpillars, ducks, deer

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3rd Trophic Level-- secondary consumers

• Organisms whose energy source comes from other
  consumers
• Divided into two groups
• Omnivores
• Carnivores

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• Omnivores
• Eat both consumers and producers
• Examples bears, crows, humans
• Carnivores
• Only eat other consumers
• Considered meat eaters
• Examples tigers, snakes, owls, dogs

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4th Trophic Level -- Top Carnivores

• Carnivores that consume other carnivores
• Example a hawk that eats a snake

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Detritivores and Decomposers

• Consumers whose energy source comes from waste
  and dead bodies from organisms of all trophic
  levels
• Cause decay or the break down of molecules
• Examples scavengers, bacteria, fungi
• Q Why are detritivores and decomposers useful?

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• Food Chain Shows only one path of energy flow
• Food Web Shows multiple paths of energy flow

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• Q What happens to the energy?
• Some is stored in the body used later for things
  like growth
• Some is lost in waste
• what the body cant digest or already has enough
  of
• Most leaves as heat
• Only about 10 of available energy is actually
  transferred from one trophic level to the next
• as you go up in trophic levels, the amount of
  useable energy goes down

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Energy Pyramid
Energy is lost
One calorie the amount of energy needed to
raise the temp of 1g (1mL) water 1ºC
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• Energy pyramids are NOT drawn based on the of
  organisms at that level
• Energy pyramids ARE drawn based on biomass and
  amount of available energy at that level
• Biomass total amount of living tissue, usually
  referring to what can be used as fuel.
• The producers level usually has the most biomass