1. Energy Flow in Ecosystems
Everything that organisms do in ecosystems require energy. The flow of energy is the most important factor that controls what kinds of organisms live in an ecosystem and how many organisms the ecosystem can support.

2. producers – organisms that capture energy from the sun
ex: plants, algae, diatoms, phytoplankton
consumers – organisms that consume plants or other organisms to obtain energy
ex: animals

3. Trophic Levels
Ecologists study how energy moves through an ecosystem by assigning organisms in that ecosystem to a specific level, called a trophic level. Energy moves from one trophic level to another with the sun being the ultimate source of energy for producers and consumers.

4. 1st trophic level – is occupied by producers, such as plants, algae, and bacteria; producers use the energy of the sun to build energy-rich carbohydrates; they are called primary producers.
2nd trophic level – consists of herbivores (animals that eat plants or other primary producers); they are called primary consumers.

5. 3rd trophic level – consists of secondary consumers or animals that eat herbivores; these animal may be carnivores (meat eaters) or omnivores (eat plants and animals); they are called secondary consumers.
4th trophic level – composed of carnivores that consume other carnivores; they are called tertiary consumers.

6. Trophic Levels sun 1° producer 1° consumer 2° consumer 1st Trophic
2nd Trophic
Level
3rd Trophic
Level

7. Food Chains
show the path of energy flow through the trophic levels of an ecosystem
the further up the food chain you go, the less food (and hence energy) is available
most food chains have no more than four or five levels because the animals at the end of the chain would not get enough food (and hence energy) to stay alive

8. Food Chains
“is eaten by”
“is eaten by”
“is eaten by”
“is eaten by”

9. decomposers – aid in the decomposition of dead or dying organisms causing decay; includes bacteria, fungi
detritivores – a special class of consumers which include worms, millipedes, slugs, dung flies; they obtain their energy from organic waste and dead bodies that are produced at all trophic levels

10. The three parts of a stable ecosystem are ___, ___, ___.

11. What type of organism does F represent?C B F

12. Food Web
is a complicated, interconnected group of food chains; food webs show a more complete picture of the feeding relationship in an ecosystem

13. Food Web
is a complicated, interconnected group of food chains; in most ecosystems, energy does not follow simple straight paths because individual animals often feed at several trophic levels; food webs show a more complete picture of the feeding relationship in an ecosystem

14. Food Web Algae Decomposers Which organism is the producer?
Which organism is missing from the food web?
Decomposers

15. Food Web Which organism is both a 1° and 2° consumer? Krill
Adelie Penguin
Cod
Squid

16. Food Web Which organism is both a 2° and 3° consumer? Adelie penguin
Cabeater seal
Leopard seal
Elephant seal
Killer whale
Cod

17. Energy Pyramid Shows the amount of energy available from one level
of a food chain to the
next.
Least Available Energy
4° consumer
3° consumer
2° consumer
1° consumer
producer
Most Available Energy

18. Energy Pyramid
A basic pyramid shape often represents a typical food chain.