1. How does energy move through the ecosystem?
Energy Flow
How does energy move through the ecosystem?

2. How does Energy Flow through Ecosystems?
All organisms require energy for life processes.
Growth
Hence for all organisms there must be:
A source of energy
A loss of usable energy
This energy is used or lost and is not available if consumed
Locomotion
What do you mean by life processes?
Reproduction

3. Conservation: Law of Conservation of Matter -
Matter cannot be created nor destroyed, only transformed from one form to another.

4. First Law of Thermodynamics also called…
Law of Conservation of Energy -
Energy can be converted from one form or another but cannot be created nor destroyed, only transformed from one form to another.

5. How does energy flow through a food chain?
Food Chain: A simple diagram of one string of feeding relationships in an ecosystem, showing the direction of the transfer of energy in that system.
Energy Flow through Ecosystems:
Food Chain – shows energy flow through a system
Sun’s energy fuels grass
Grass’s energy fuels the rabbit
Rabbit fuels the wolf
After it dies, the wolf fuels the bacteria to break down the parts of the wolf back into the soil
The nutrients in the soil fuel the grass
AND SO ON
Sun Grass Rabbit Wolf Bacteria
Soil

6. Energy: 2nd Law of Thermodynamics:
When energy is changed from one form to another, some energy will be lost to the larger environment.
Nothing is ever 100% efficient.
This is due to entropy (nature’s tendency towards randomness).

7. 2nd law of thermodynamics in action:
When energy is changed from one form to another, some energy will be lost
Why? Rabbit moves, respires, grows, etc.. Energy is used, no longer available if eaten.
Energy Flow through Ecosystems:
Food Chain – shows energy flow through a system
Sun’s energy fuels grass
Grass’s energy fuels the rabbit
Rabbit fuels the wolf
After it dies, the wolf fuels the bacteria to break down the parts of the wolf back into the soil
The nutrients in the soil fuel the grass
AND SO ON
Sun Grass Rabbit Wolf Bacteria
Soil

8. What are the parts of a food chain?
Producers
Organisms that make their own food from inorganic molecules and energy.
eg. Plants, blue-green algae
Most accomplish energy building through photosynthesis
Inorganic Molecules = molecules that are not part of a living organism
Energy is almost always from the sun (very rare exceptions)
Parts of the food chain:
Producer: able to make food from inorganic molecules (molecules that are not part of a living organism) and energy (typically from the sun, although other processes do happen)
Example – plants, blue-green algae
Photosynthesis: how plants convert energy to food (sugar)
H20 + sunlight (energy) + CO2  Sugar + O2
Water + Carbon Dioxide + Sunlight  Sugar + Oxygen

9. Consumers Organisms that cannot make own food.
Consumers are: all animals, fungi and most bacteria
They must obtain energy by eating other organisms — through a process called cellular respiration
Sugar + Oxygen  Carbon Dioxide + Water ATP (energy)
Consumers = cannot make their own food; must get their energy by eating other organisms
Examples – all animals, fungi, and most bacteria
Get their energy by burning food (that sugar of the organism they ate)
So, we call that process of burning food to get energy CELLULAR RESPIRATION:
sugar (found in the organism they just ate) + O2 (breathing)  ENERGY + H2O + CO2

10. Consumers… Primary consumer (10) – eats plants (it’s a herbivore)
Consumers…
Primary consumer (10) – eats plants (it’s a herbivore)
Secondary consumer (2o) – eats a primary consumer
Tertiary consumer (3o) – eats a secondary
consumer
Levels of Consumers:
1.) Primary consumers – eat only plants (or blue-green algae) – note the special way we write primary (10)
2.) Secondary consumers – eat primary consumers
3.) Tertiary consumers – eat secondary consumers
So, as you follow a food chain, you should be able to label the consumers by beginning with the organism that eats the plant!

11. Consumers… Herbivores – eat plants or algae
Carnivores – eat other animals

12. Consumers… Omnivores — eat both producers and consumers
Scavengers —usually don’t hunt live prey — feed on bodies of dead organisms

13. Decomposers Bacteria and fungi that break down organic material
Decomposers are essential to ecosystem health because they recycle nutrients back for producers to reuse.

14. Food Chain with Labels Sun 10 Consumer 20 Consumer Producer Decomposer
herbivore
Carnivore

15. What is a Food Web?
a group of food chains showing all of the feeding relationships in an ecosystem.
Food Web = multiple food chains so you can see multiple relationships
Relationships – how organisms are connected
Trophic Level – one layer of a food chain/food web
For example:
- All producers are in the same trophic level
- All primary consumers are in the same trophic level
Biomass:
Bio = living
Mass = matter or weight of material
ORGANIC = is currently living or lived in the past

16. Food Web Sun Human Wolf Fox Sheep Bacteria Rabbit Mice Deer
Grass Flower Carrots
Nutrient Rich Soil
Food Webs are complex – notice how many different connections exist.
For example:
Energy goes from the sun to many producers (grass, flowers, carrots)
Rabbits get energy from grass and flowers and provide energy to foxes, human
AND SO ON

17. Biological Magnification
Increasing concentration of a substance in the tissues of organisms in the higher levels in a food chain or web. (Nearly always something dangerous, like a toxin)
Many toxins in the water
Many toxins in the person

18. Video on Biological Magnification
Biological Magnification- accumulation of increasing amounts of toxin within tissues of organisms.
Video on Biological Magnification

19. Organic = is currently living or lived in the past
Trophic Levels
Trophic level — a layer in the feeding relationship of an ecosystem, one link in the food chain/web.
Biomass — total amount of organic material present in a trophic level.
So, all producers are at the same trophic level and all primary consumers are at the next trophic level.
Organic = is currently living or lived in the past
Food Web = multiple food chains so you can see multiple relationships
Relationships – how organisms are connected
Trophic Level – one layer of a food chain/food web
For example:
- All producers are in the same trophic level
- All primary consumers are in the same trophic level
Biomass:
Bio = living
Mass = matter or weight of material
ORGANIC = is currently living or lived in the past

20. Energy Pyramids Another way to look at trophic levels.
a diagram showing the relative amounts of energy/biomass in the different trophic levels.
Lowest trophic levels are at the bottom: Producers have the greatest biomass.
Energy/Ecological Pyramids – another way to look at trophic levels
Lowest trophic levels are at the bottom = producers = the most biomass
The primary consumers that eat those producers are the next step up on the pyramid (lower biomass – in the whole world and in each smaller ecosystem, there are fewer primary consumers than producers)

21. Example of an Energy Pyramid
1 pound MAN
10 pounds FOXES
100 pounds RABBITS
1000
pounds of
GRASS
MAN
0.1%
Energy Lost during conversion to heat, waste….
10%
100 %
of the
sun’s energy
FOX
90% 1%
10%
Rabbit
RABBIT
10%
90%
10%
Grass
90%
Example of an energy pyramid using a single food chain:
The decreasing size of the pyramid shows that each level of the pyramid has a smaller and smaller number of those organisms.
The arrows showing 10% mean that only 10% of the energy that an organism gets actually goes into making part of the organism’s body.
The blue arrows showing 90% leaving the pyramid represent energy that is used up by the organism just to live (and is NOT available for whatever eats that organism later).
- The decreasing size of the pyramid shows that each level of the pyramid has a smaller and smaller number of those organisms.