1. The Flow of Energy

2. Learning Objectives
Know that the initial energy source of almost all food chains is….
Know what Food Chains show
Know what Food Webs show
Know the labels for each level of a food web/chain
Recognize how Pyramids can show levels of energy, mass, or consumers

3. The Sun by far has the most influence on life on earth
The Sun provides the starting point for almost all the energy that life on earth eventually uses
Pg 68
The sun is the starting point for food chains, food webs and energy pyramids (thanks to photosynthesis):

4. A terrestrial food chain
Food Chains
Quaternary consumers
Tertiary consumers
Secondary consumers
Primary consumers
Primary producers
Carnivore
Herbivore
Plant
Zooplankton
Phytoplankton
A terrestrial food chain
A marine food chain
Shows a single path of energy flow in an ecosystem
Consumer/ Heterotrophs:
must eat other organisms
for food
Producer/ Autotrophs:
makes its own food 
Pg 69

5. Food Chain: This picture properly shows the sun as starting point & decomposers (often bacteria and fungi) that break down dead material and recycle nutrients for producers to reuse

6. Food Webs
Shows multiple paths of energy flow in an ecosystem (it’s several food chains put together)
Pg 71

7. Food Webs
Shows multiple paths of energy flow in an ecosystem (it’s several food chains put together)
Simplified Version:
Sea nettle
Fish larvae
Zooplankton
Fish eggs
Juvenile striped bass
Pg 71

8. Smaller toothed whales
Food Webs
Humans
Baleen whales
Crab-eater seals
Birds
Fishes
Squids
Leopard
seals
Elephant
Smaller toothed whales
Sperm whales
Carnivorous
plankton
Euphausids
(krill)
Copepods
Phyto- plankton
Shows multiple paths of energy flow in an ecosystem (it’s several food chains put together)
Pg 71
More accurate version

9. Pg 71

10. Time for Pyramids, Pyramids and more Pyramids

11. Energy Pyramids Shows the “amount” of energy at each trophic level
-Only 10% of the energy
in any one level goes to the
next, the other 90% is
Used or lost as heat
Pg 72

12. Energy Pyramids J = joule unit of energy Pg 72 Tertiary consumers
Secondary
Primary
producers
1,000,000 J of sunlight
10 J
100 J
1,000 J
10,000 J
J = joule
unit of energy
Pg 72

13. Biomass
Pyramids
Pg 72
Shows the “amount” of mass that gets transferred to each trophic level
Your book implies, once again, that only 10% of the total mass makes to the next level up…

14. …in reality it is not usually so stable a % and in fact, while this is the most common shape of the biomass pyramid…
(a) Most biomass pyramids show a sharp decrease in biomass at successively higher trophic levels, as illustrated by data from a bog at Silver Springs, Florida.
Trophic level
Dry weight
(g/m2)
Primary producers
Tertiary consumers
Secondary consumers
Primary consumers
(14%)
11 (30%)
(4%)
809

15. Primary producers (phytoplankton) Primary consumers (zooplankton)
…some rare aquatic ecosystems biomass pyramids can actually be reversed…
Trophic level
Primary producers (phytoplankton)
Primary consumers (zooplankton)
(b) In some aquatic ecosystems, such as the English Channel, a small standing crop of primary producers (phytoplankton) supports a larger standing crop of primary consumers (zooplankton).
Dry weight
(g/m2) 21 4

16. Pyramid of Numbers
- Represents the number of individual organisms in each trophic level in one area
Pg 73

17. Its been argued that eating meat is a relatively inefficient way of using photosynthetic production
Worldwide agriculture could feed many more people if they all fed more efficiently, eating only plant material
Trophic level
Secondary
consumers
Primary
producers
End