1. Chapter 2 Energy flow and nutrient cycles support life in ecosystems

2. 2.1 Energy Flow in Ecosystems

3. Why is energy important?

4. Every living thing uses energy to survive
Cell functions
Movement
Reproduction
Building tissues (from wood to muscle)

5. Reading activity: Text book (58-63)
2.1 Key term chart.
Define each term in your own words
Give an example for each term.

6. Bill Nye video food web

7. 2.1 Energy Flow in Ecosystems
Biomass is the total mass of all living things in a given area. (measured in g/m2 or kg/m2)
Organisms interact with the ecosystem by:
Obtaining food from the ecosystem
Contributing energy to the ecosystem

8. Energy Flow in Ecosystems
Plants are called producers because they make carbohydrates during
photosynthesis.
CO2 + H2O + sunlight  C6H12O6 + O2
Consumers get their energy by feeding on producers or other consumers.
- Decomposers break-down wastes &
dead organisms, through the process of biodegradation.

9. Producer
Consumer
Decomposers

10. Energy Flow & Energy Loss in Ecosystems
Methods to represent energy moving through ecosystems.
Food chains: show the flow of energy in an ecosystem.
Food webs: represent interconnected food chains. They model the feeding relationships in an ecosystem
Food pyramids: show the changes in available energy from one trophic level to another in a food chain. They’re also called ecological pyramids

11. Primary Producer
Energy from Sun
Primary Consumer
Secondary Consumer
Tertiary Consumer

12. Primary Producer Primary Consumer Secondary Consumer Tertiary Consumer
First Trophic Level
Primary Consumer
Second Trophic Level
Secondary Consumer
Third Trophic Level
Tertiary Consumer
Fourth Trophic Level

13. Food Chains Each step is a trophic level Producers = 1st trophic level
Primary consumers
= 2nd trophic level
Secondary consumers
= 3rd trophic level
Tertiary consumers
= 4th trophic level

14. This dung beetle is a detrivore.
Consumers in a food chain can be classified as:
Detrivores (decomposers) - obtain energy & nutrients from dead organisms & waste matter.
they have their own, separate food chains & they feed on every trophic level.
Eg. small insects, earthworms, bacteria
& fungi
Herbivores - primary consumers
eat plants (producers) only
Ex. Horse eating hay
This dung beetle is a detrivore.

15. 3. Carnivores - secondary or tertiary consumers
Secondary consumers eat non-producers (herbivores)
Eg. Frog eating a grasshopper
Tertiary consumers eat secondary
consumers
also called top predators, top
carnivores or top consumers
Eg. Lions eating humans
4. Omnivores - consumers that eat both
plants & animals
Eg. include humans and bears

16. Detrivores &Decomposers
Energy Flow
Within an organism’s niche, the organism interacts with the ecosystem by:
-Obtaining food from the ecosystem
-Contributing energy to the ecosystem
Detrivores &Decomposers

17. E. Coli

18. Food Webs Most organisms are part of many food chains.
Arrows in a food web represent the flow of energy and nutrients.
Following the arrows leads to the top carnivore(s).
This food web represents a terrestrial ecosystem that could be found in British Columbia.

21. Food Pyramids
Energy enters at the first tropic level (producers), where there is a large amount of biomass & therefore a lot of energy

22. It takes large quantities of organisms in one tropic level to meet the energy needs of the next trophic level.
80% - 90% of energy taken in by consumers is used in chemical reactions in the body, or is lost as heat energy.

23. 100kj – 90kj = 10kj
10/100 X 100% = 10% left over

24. The amount of life an ecosystem can sustain is based on the bottom level of the ecological pyramid, where producers capture energy from the sun.

25. Lower trophic levels have much larger populations than upper levels.
This shows the importance of maintaining large, biodiverse
populations at the lowest levels of the food pyramid.

26. 5 Lowest population, biomass and energy
Highest population, biomass and energy

27. Pyramid of Numbers

28. Biomass Pyramid

29. Energy Pyramid

30. RC p64 #1-5
CC P67 #4,5,8,12