1. Our Ecosystem…..
The Circle of Life

2. Ecosystem….
All of the biotic (living) and abiotic (non-living) factors in an area and the organisms within that system

3. Organisms in the Ecosystem
In an ecosystem, each organism has a…
Habitat = where an organism lives, its “address”
Niche = what an organism does, its “job”
Trophic Level = energy or feeding level

4. Trophic Levels Producers Primary Consumers Secondary Consumers
Produce their own food
Ex: plants, trees, flowers….
Primary Consumers
Eat the producers
Ex: rabbits, deer, cows, chickens
Secondary Consumers
Eat the primary consumers
Ex: humans, fox, salmon

5. Trophic Levels cont…. Tertiary Consumers Scavengers Decomposers
Eat secondary consumers
Ex: sharks, bears, hawks
Scavengers
Eat something someone else killed
Ex: crows, vultures, hyenas
Decomposers
Eat dead material (detritus)
Ex: bacteria, fungus, worms

6. You are what you eat…. Autotrophs Make their own food within itself
Ex: plants

7. Heterotrophs
Organisms that cannot make their own food must eat something
Herbivores
Eat only plants
Carnivores
Eat only animals
Omnivore
Eat both plants and animals

8. Energy Flow in an Ecosystem
All energy in an ecosystem comes from the sun
This energy then will move up through the various trophic levels
An ecological pyramid shows the relationship between producers and consumers at different trophic levels in an ecosystem

9. The Tropic Level Pyramid

10. The 10% Law
As you go up each level of the energy pyramid, 90% of the energy is lost!
Only 10% is actually transferred from one level to the next!!
The energy is either lost as heat or not eaten/digested…therefore this energy cannot be transferred on to the next level.

13. Just another look

14. Showing Energy Transfers
We can use food chains and food webs to show the series of steps through which energy is transferred
Food Chain = a single pathway of food and energy through a community
Food Web = a series of interconnected food chains
The arrows must point in the direction that the energy is being transferred
IOW…it points to who is doing the eating

15. A Food Chain
Jay

18. Review What is a habitat? What is a niche? What is an autotroph?
Where an organism lives.
What is a niche?
An organism’s job
What is an autotroph?
An organism that can make its own food.
What are the 4 trophic levels?
Producers, primary, secondary, tertiary consumers
What is a food web?
An interconnected series of food chains

19. Any Questions??