1. Ecosystems and Energy
Biology

2. Vocabulary Primary Producer Autotroph Primary Consumer Biomass
Secondary Consumer
Tertiary Consumer
Herbivore
Carnivore
Omnivore
Decomposer/Detritivore
Autotroph
Biomass
Energy Pyramid
Food Chain
Food Web
Heterotroph
Trophic Level

3. Looking closely at Ecosystems
All Ecosystems are made of four components linked by the flow of energy.
These components are:
• Primary Producers
• Consumers
• Decomposers
• Abiotic Environment

4. Looking closely at Ecosystems
External energy source
PRIMARY
PRODUCERS
CONSUMERS
DECOMPOSERS
ABIOTIC ENVIRONMENT

5. Primary Producers
Producers make their own food, from abiotic factors, such as sunlight or heat from chemical reactions.

6. Producers are also known as Autotrophs
Primary Producers
Producers are also known as Autotrophs
Some examples are:
• Plants
• Algae
• Bacteria

7. Consumers
Consumers are organisms that get their energy by eating other organisms

8. Consumers are also known as Heterotrophs
Consumers can be:
• Herbivores
• Carnivores
• Omnivores
• Detritivores (Decomposers)

9. Herbivores eat only plants.
Consumers
Herbivores eat only plants.
Herbivore Examples:
• Large Mammals (Such as cattle & deer)
• Insects

10. Carnivores eat other animals
Consumers
Carnivores eat other animals
Carnivore Examples:
• Lions, Tigers
• Wolves
• Sharks
• Snakes

11. Omnivores eat both plants and animals
Consumers
Omnivores eat both plants and animals
Omnivore Examples:
• Humans
• Bears
• Mice
• Pigs

12. Detritivores eat dead plants and animals (also called decomposers)
Consumers
Detritivores eat dead plants and animals (also called decomposers)
Detritivore Examples:
• Worms
• Beetles
• Bacteria
• Fungi

13. Food Chain
A Food Chain tells us what eats what in an ecosystem. It shows the series of organisms through which food energy is passed.

14. Food Chain The arrow means “is eaten by”
In this case the dragonfly is eaten by the frog.

15. Food Chain Remember… ALL food chains begin with a Producer
( Also known as an Autotroph)

16. Food Web In an ecosystem, there are many producers and consumers.
Instead of a food chain, we can use a food web.

17. Food Web
Humans
Blue whale
Sperm whale
Crabeater seal
Killer
whale
Elephant
seal
Leopard
Adélie
penguins
Petrel
Fish
Squid
Carnivorous plankton
Krill
Phytoplankton
Herbivorous
zooplankton
Emperor
penguin
A food web shows the complex relationship formed by the overlapping and interconnecting food chains.

18. To better understand a food web, we can look at an energy pyramid.
An energy pyramid is a way to graph how much energy is passed up the food chain from one organism to the next.

19. Energy Pyramid Let’s look at the energy pyramid closer.
Each layer of the pyramid is called a Trophic Level.
A Trophic Level is a level of nourishment in a food chain.

20. Energy Pyramid Let’s look at the energy pyramid closer.
The pyramid first shows us the Producers.
Remember… Producers get their energy from the sun.
Producers are the first and largest Trophic Level.
Producers

21. Energy Pyramid Let’s look at the energy pyramid closer.
Second, we see the Primary Consumers
The Primary Consumers get their energy from eating the Producers.
Primary Consumers can be either Herbivores or Omnivores.
Primary Consumers

22. Energy Pyramid Let’s look at the energy pyramid closer.
Third, we see the Secondary Consumers
The Secondary Consumers get their energy from eating the Primary Consumers
Secondary Consumers are Carnivores or Omnivores
Secondary Consumers

23. Energy Pyramid Let’s look at the energy pyramid closer.
Fourth, we see the Tertiary Consumers
The Tertiary Consumers get their energy from eating the Secondary Consumers
Tertiary Consumers are Carnivores or Omnivores
Tertiary Consumers

24. Energy Pyramid Let’s look at the energy pyramid closer.
Some energy pyramids can have a fifth Trophic Level.
Usually this fifth level is humans.

25. Let’s look at the energy pyramid closer.
Biomass is the total amount of living tissue within each trophic level.

26. Energy Pyramid Let’s look at the energy pyramid closer.
Only 10% of the energy from the prior trophic level is passed on.
This is because energy is lost to the environment as heat

27. Herbivores?
Carnivores?
Producers
Secondary Consumers?
Tertiary Consumers?
Primary C? REVEAL

28. Type of Consumers (Herbivore, etc.) Biomass Energy Flow
Now, explain to a classmate all of the information that is given by this pyramid.
Be sure to mention:
Trophic levels
Producers/Consumers
Type of Consumers (Herbivore, etc.)
Biomass
Energy Flow
Herbivores?
Carnivores?
Producers
Secondary Consumers?
Tertiary Consumers?
Primary C? REVEAL

29. Energy Pyramid
If an energy pyramid consists of plants that contain 500,000 calories of food energy, how many calories of energy would be available to consumers at each of the next three trophic levels?
Trophic level
Primary producers
Tertiary consumers
Secondary consumers
Primary consumers

30. Energy Pyramid Primary Consumers: Secondary Consumers:
500,000 cal x .1 = 50,000 calories
Secondary Consumers:
50,000 cal x .1 = 5,000 calories
Tertiary Consumers:
5,000 cal x .1 = 500 calories
Trophic level
Primary producers
Tertiary consumers
Secondary consumers
Primary consumers

31. What does these energy numbers tell us??
Food Web
What does these energy numbers tell us??
There are very few Tertiary consumers, because it takes a HUGE amount of food energy to support them.
For a large population to exist, it needs to feed from the LOWEST trophic level possible, because there is more food energy available.
Trophic level
Primary producers
Tertiary consumers
Secondary consumers
Primary consumers

32. Besides the energy pyramid, we can also have pyramids of:
Other Pyramid types
Besides the energy pyramid, we can also have pyramids of:
Numbers
Biomass

33. Pyramid of Numbers
A pyramid of numbers reflects the number of species at each trophic level.
For example: if we look at a forest, there may be few rose bushes, but many insects that feed on the tree, with a pyramid like the one below.
Where is the most biomass?
Where is the most energy?
Where at the primary consumers? Secondary? Tertiary?
Producers?
Where are the heterotrophs?
Autotrophs?

34. For example: Looking at the same forest, the biomass is great.
Pyramid of Biomass
A pyramid of biomass reflects the total amount of living tissue at each trophic level.
For example: Looking at the same forest, the biomass is great.
Just a snapshot of time, miht be diff year to year, or diff in winter vs summer
Can be inverted…
Not counting each one… it’s just taking a snapshot in time.