1. We have studied how matter cycles through the 4 spheres, but how does energy cycle?
Ecosystems

2. ECOLOGY- the study of organisms in their environment
biosphere
ecosystem
community
population
organism

3. Essential question
How does energy move through the ecosystem?

4. Ecosystem
All the organisms in a community plus all the abiotic factors
ecosystems are transformers of energy & processors of matter
Ecosystems are self-sustaining, but what is needed?
capture energy
transfer energy
cycle nutrients

5. Ecosystem inputs nutrients cycle inputs energy nutrients
biosphere
energy flows through
constant input of energy
nutrients cycle
Matter cannot
be created or destroyed
Don’t forget the laws of Physics!
nutrients can only cycle
inputs
energy
nutrients

6. Generalized Nutrient cycling
consumers
consumers
consumers
producers
decomposers
decomposers
nutrients ENTER FOOD CHAIN = made available to producers
nutrients made available to producers
return to abiotic reservoir
Decomposition connects all trophic levels
abiotic reservoir
abiotic reservoir
geologic processes
geologic processes

7. Energy flows through ecosystems
sun
secondary consumers
(carnivores)
loss of energy
loss of energy
primary consumers
(herbivores)
producers (plants)

8. Food chains Trophic levels sun feeding relationships
Tertiary consumer
Trophic levels
feeding relationships
start with energy from the sun
captured by plants
1st level of all food chains
food chains usually go up only 4 or 5 levels
inefficiency of energy transfer
all levels connect to decomposers
top carnivore
Level 3
Secondary consumer
carnivore
Level 2
Primary consumer
heterotrophs
herbivore
Level 1
Producer
autotrophs
Fungi
Decomposers
Bacteria

9. Inefficiency of energy transfer
sun
Inefficiency of energy transfer
Loss of energy between levels of food chain
To where is the energy lost? The cost of living!
17%
growth
energy lost to daily living
only this energy moves on to the next level in the food chain
33%
cellular
respiration
50%
waste (feces)

10. Ecological pyramid sun Loss of energy between levels of food chain
can feed fewer animals in each level 1
100
100,000
1,000,000,000

11. Food webs Show in a more complicated way how energy flows
A species may weave into web at more than one level