1. Energy Flow in an Ecosystem

2. Energy Flow Energy in an ecosystem originally comes from the sun
Energy flows through Ecosystems from producers to consumers
Producers (make food)
Consumers (use food by eating producers or other consumers)

3. Producers
Sunlight is the main source of energy for most life on earth.
Producers contain chlorophyll & can use energy directly from the sun

4. Autotrophs
An Autotroph is any organism that can produce its own food supply!
Autotrophs are also called Producers
Plants, algae, some protists, & some bacteria are examples

5. Niche of a Producer
Captures energy and transforms it into organic, stored energy for the use of living organisms.
May be photo-autotrophs using light energy (e.g. plants)
May be chemo-autotrophs using chemical energy (e.g. cyanobacteria)

6. Photoautotroph Producer That Captures Energy from the sun by:
Photosynthesis
Adds Oxygen to the atmosphere
Removes Carbon Dioxide from the Atmosphere
Algae

8. Photosynthesis 6CO2 + 6H2O + chlorophyll  C6H12O6 + 6O2

9. 6O2 + C6H12O6 ---> 6H2O + 6CO2 + energy
CELLULAR RESPIRATION is the chemical reaction that releases the energy (ATP) in glucose.

10. Cellular respiration reactions

11. Habitat of Photoautotrophs
On Land
Plants
In The Sea
Algae
Tidal Flats & Salt Marshes
Cyanobacteria

12. Called a Black smoker (thermal vent)
Chemoautotrophs
Capture energy from the bonds of inorganic molecules such as Hydrogen Sulfide
Process is called Chemosynthesis
Often occurs in deep sea vents or gut of animals
Called a Black smoker (thermal vent)

13. Tube Worms living in Black Smoker

14. Some energy in the primary consumer is STORED & not lost to the atmosphere or used by the consumer itself.
This energy is available for another consumer (predator).

15. Heterotrophs eat other organisms to obtain energy. (e.g. animals)
Consumers
Heterotrophs eat other organisms to obtain energy. (e.g. animals)
Herbivores
Eat Only Plants
Carnivores
Eat Only Other
Animals

16. Consumers Heterotrophs eat other organismsto obtain energy.
Omnivores (Humans)
Eat Plants & Animals
Detritivores (Scavengers)
Feed On Dead Plant & Animal Remains (buzzards)
Decomposers
Fungi & Bacteria

17. Trophic Levels, Energy Transfer and Pyramids

18. Feeding Relationships
Energy flows through an ecosystem in one direction from producers to various levels of consumers

19. The transfer of energy from the sun to producer to primary consumer then to higher order consumers can be shown in a FOOD CHAIN.

20. Vocabulary
Trophic Levels – is the position an organism occupies in a food chain. It refers to food or feeding.
Apex predator – top level predators with few or no predators of their own.

21. Food Chain

22. Food Chains
The energy flow from one trophic level to the other is know as a food chain
Producers are at the first TROPHIC LEVEL
Primary Consumers are the SECOND TROPHIC LEVEL
Secondary consumers are at the THIRD TROPHIC LEVEL

23. Trophic Levels (feeding levels)3 2 1

24. Food Web Most organisms eat more than JUST one organism
When more organisms are involved it is know as a FOOD WEB
Food webs are more complex and involve lots of organisms

25. Food Webs
Food webs show ALTERNATIVE PATHWAYS other possible pathways through which an organism can obtain energy

26. Food webs

27. Grass Mouse Grasshopper Frog Owl Hawk Trophic Level
Producer, primary consumer, secondary consumer, tertiary consumer?
Grass
Mouse
Grasshopper
Frog
Owl
Hawk

28. Secondary and tertiary consumer
Trophic Level
Producer, primary consumer, secondary consumer, tertiary consumer
Grass
1st
Producer
Mouse
2nd
Primary consumer
Grasshopper
Frog
3rd
Secondary consumer
Owl
3rd and 4th
Secondary and tertiary consumer
Hawk

30. Transfer of Energy
When a lion eats a zebra, it does not get all of the energy from the zebra.
Energy lost is usually in form of heat
Energy lost from chain “link” to “link” is significant!

31. from grass to sheep, loss is about 90%!
HEAT
90%
HEAT
90%
100% Energy Available
10% Original Energy!
1% Original Energy!

32. Energy lost from one trophic level (energy level) to the next level can be represented by a pyramid
4⁰ CONSUMERS
3 CONSUMERS
2 CONSUMERS
1 CONSUMERS
PRODUCERS

33. Each level above only gets 10% of the energy from below
Ex: 10,000 J of producers (plants) only give 10% of energy to primary consumers
1,000 J to primary consumers (snails, minnows, dragonflies)
100 J to secondary consumers (small fish)
10 J to tertiary consumers (big fish)
1 J to quaternary consumers (fish hawk)

34. ENERGY PYRAMID
1 J
10 J
100 J
1,000 J
10,000 J

35. Energy Pyramid

39. Three hundred trout are needed to support one man for a year
Three hundred trout are needed to support one man for a year. The trout, in turn, must consume 90,000 frogs, that must consume 27 million grasshoppers that live off of 1,000 tons of grass G. Tyler Miller, Jr., American Chemist (1971)

40. Usually no more than 5 trophic levels since 6th level would have very little energy to keep it alive

41. Ecological Pyramid
Which level has the most energy?
Which level has the most organisms?
Which level has the least organisms?
Which level has the least energy?

42. Pyramid of Numbers
Shows the numbers of individual organisms at each trophic level in an ecosystem.
tertiary
consumers
secondary
primary
producers 5
5000
500,000
5,000,000
A vast number of producers are required to support even a few top level consumers.

43. Biomass pyramid
Biomass is a measure of the total dry mass of organisms in a given area.
tertiary
consumers
secondary
primary
producers
75 g/m2
150g/m2
675g/m2
2000g/m2

44. Name the Producer, Consumers & Decomposers in this food chain:

46. Food Web