CHAPTER 22- ENERGY FLOW

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CHAPTER 22- ENERGY FLOW

• ALL LIFE DEPENDS ON THE SUN
• PHOTOSYNTHESIS? the process of using the suns
  energy, water, and carbon dioxide to produce
  Oxygen and the sugar glucose (carbohydrates)

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Producer-

• Defined as an organism that can make its own food
• Scientific term is AUTOTROPH will literally
  stands for self- feeding
• Examples are plants, some protists, and some
  bacteria-

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PRODUCERS

• almost all of them use the green pigment
  (chlorophyll) to capture the energy from the sun
• EXCEPTION- deep water ecosystems which use energy
  from deep ocean vents. Bacteria can break down
  the hydrogen sulfide to make its own energy

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CONSUMER

• Defined as organisms that get their energy by
  eating other organisms
• Scientific term is HETEROTROPH which literally
  means other feeders
• Examples- animals, fungi

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CLASSIFICATION based on what consumers eat

• HERBIVORES- consumer that only eats producers
• CARNIVORES-consumer that only eats other
  consumers
• OMNIVORES- consumer that eats both producers and
  consumers
• DECOMPOSERS-consumer that break down dead
  organisms

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How do consumers get their energy?

• Use oxygen we breathe to breakdown the sugar
  glucose
• This is called CELLULAR RESPIRATION
• Each cell in our body takes in oxygen and use it
  to release energy from food

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CELLULAR RESPIRATION

• ALL ORGANISMS USE CELLULAR RESPIRATION TO GET
  ENERGY FROM FOOD
• EVEN PRODUCERS USE CELLULAR RESPIRATION
• ENERGY IS USED FOR GROWTH, CELL REPAIR, MOVEMENT,
  ETC
• EXCESS ENERGY IS STORED AS FAT OR SUGAR

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ENERGY TRANSFER

• Each time one organism eats another organism
  there is an energy transfer
• Scientists study energy transfer by examining
• FOOD CHAINS
• FOOD WEBS
• TROPHIC LEVELS

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FOOD CHAIN (pg 122)

• Sequence in which energy is transferred from one
  organism to the next as each organism is eaten

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FOOD WEB

• Many food chains linked together
• More realistic because most animals eat more than
  one type of food
• Shows good interaction in the ecosystem

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TROPHIC LEVEL

• Defined as each step in the energy transfer of a
  food chain
• Will rarely have more than 4 consumer levels
• This is due to energy loss from one level to the
  next

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TROPHIC LEVELS

• EACH TIME ENERGY IS TRANSFERRED FROM ONE LEVEL TO
  THE NEXT ENERGY IS LOST AS HEAT AND LESS ENERGY
  IS AVAILABLE
• About 90 of energy is used up
• Only 10 of energy is passed on

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ENERGY PYRAMID

• Shows the relationship of consumers in an
  ecosystem and how energy is transferred
• - Each step in the pyramid is a power of ten

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BIO MASS

• Amount of living mass in a trophic level

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CYCLING OF ELEMENTS

• Law of Conservation of Mass- the amount of mass
  in the universe remains constant- therefore the
  amount of mass of each element in the universe
  remains constant (exception is radioactive
  materials)

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WATER CYCLE
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CARBON CYCLE

• All living things are made of carbon
• Carbon is the key ingredient in fats, proteins,
  sugars, and nucleic acids
• Carbon is found in the air and water (Carbon
  Dioxide)
• Carbon is also found in the soil naturally as
  limestone or as the remains of once living
  organisms- oil, coal, and natural gas

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How do humans affect the Carbon cycle?

• When we burn fuel (oil, coal, gas, wood) we
  release carbon dioxide into the atmosphere
• CELLULAR RESPIRATION- gives off CO2
• Increased carbon dioxide in atmosphere can lead
  to global warming

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CARBON CYCLE
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NITROGEN

• Organisms need nitrogen to form proteins
• Nitrogen makes up 78 of the atmosphere
• Most organisms cannot use nitrogen as a gas to
  make proteins
• Nitrogen fixing bacteria turns atmospheric
  nitrogen into usable nitrogen in the soil
• Decomposers turn waste products and decaying
  organisms into usable nitrogen

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PHOSPHORUS CYCLE

• Needed to form bones and teeth in animals
• Phosphate rocks dissolve and release into the soil

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HOW ECOSYSTEMS CHANGE

• If a Forest burns down for 80 acres then
• 1. What plants would you expect to see first?
• 2. What animals would you expect to see?
• 3. What would that area look like in 20 years?
  What plants and animals?

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ECOLOGICAL SUCCESSION

• Defined as- the gradual change and replacement of
  types of species in a community
• Example- first grass would grow- then bushes
  may grow and kill off small areas of grass then
  large trees grow and kill off all of the forest
  floor plant life

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Primary Succession

• Succession that occurs on a surface where no
  ecosystem existed before
• Examples- new island formed by a volcano, sand
  dunes
• What would you expect to see there?

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Secondary Succession

• Succession on a surface where an ecosystem
  previously existed
• Example- forest burning down, chopping down rain
  forest, flood, volcano, tsunami

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PIONEER SPECIES

• First organisms to colonize a new area-
• Characteristics of pioneer species
• 1. fast reproducers- short lifespan
• 2. produce many offspring
• 3. have good method of dispersal
• 4. can remain dormant in rough environment if
  needed
• 5. small- and not good competitors

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MATURE SPECIES

• Defined as a species that will eventually
  dominate an ecosystem if given enough time
• Characteristics-
• 1. slow reproducers but long life span
• 2. produce few offspring but care for young
• 3. slower dispersal
• 4. larger and very good competitors

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CLIMAX COMMUNITY (page 132)

• Is the final and stable community when it fully
  matures