Download Energy Flow in the Environment

Where does the Ecosystem get its
ENERGY???
Sunlight is the MAIN energy source for a
life on earth
A few ecosystems do not get
their energy from the sun…
they get it from chemicals!
Ocean Vents with no sunlight
After the sun…
Energy is obtained from FOOD
Organisms either…
1. Make their own food from sunlight/chemicals
AUTOTROPH
PRODUCERS
2. Depend on other organisms for food
HETEROTROPH
CONSUMERS
Autotrophs/ Producers
 Examples:
Plants, Algae
 Autotrophs/Producers: begin all
food chains and are essential for
the flow of energy through the
environment
Autotrophs produce their own
food through…
Photosynthesis: provides a vital
connection between the sun and the
energy needs of all living things.
6CO2 + 6H2O + Energy --> C6H12O6 + 6O2
Autotrophs also produce their own
food through…
Chemosynthesis: is the process by which
food (glucose) is made by bacteria using
chemicals as the energy source, rather than
sunlight.
Chemical Energy
Hot Spring Bacterial Mats
Chemosynthesis
Bacteria live in the
mussel and make
excess food, which
the mussel uses for
respiration.
Types of
Heterotrophs/ Consumers
1. HERBIVORES
Obtain energy by eating only plants
Also called Primary Consumers;
they are the first to eat.
2. Carnivores
Feed on other animals
a. Scavenger – Feeds off prekilled animals
b. Predator- Hunts and kills
prey
Carnivores cont.
c. Parasite- Feed off of a living
organism. (host)
3. Omnivore
Eat both plant and animal
4. Decomposers
Break down organic wastes and
remains (dead organisms) by recycling
nutrients back to soil and air for reuse
Bacteria, Saphrophytic Fungus
Energy Flow
Energy flows through the environment
in one direction, through a series of
steps.
Sun
autotrophs
heterotrophs
decomposers
Arrows show direction of energy
movement
Energy Flow
Energy flow can be represented in
three different ways
1. Food chains
2. Food webs
3. Energy/Ecological pyramids
Food Chain
Shows the transfer of
energy though an ecosystem.
Autotroph
Heterotroph
Heterotroph
Heterotroph
Producer
Herbivore
Carnivore
Carnivore
Plant
10 Consumer
20 Consumer
30 Consumer
Grass
Animal
Animal
Animal
Grasshopper
Moles
Owl
Food Web
Where is the energy lost?
1000 cal/unit
Shark
Squid
0.1 cal./g
Small fish
1 cal./g
Zooplankton
10 cal./g
Algae
100 cal./g
***food chain can only
have 4 or 5 levels
Only about 10% of the
energy is able to move.
The rest is used by the
organism for life and
lost as heat to the
environment
Where is the energy lost?
energy lost
daily living
10%
growth
only this energy
moves on to the
next level in
the food chain
40%
cellular
respiration
50%
waste (feces)
Energy flows through…
sun
secondary
consumers
(carnivores)
loss of
energy
loss of
energy
primary consumers
(herbivores)
loss of
energy
producers (plants)
Energy Pyramid
 Shows the relative amount of energy available
at each trophic level!
Energy Pyramid
Less Energy
= Smaller #
of Species!
Biomass Pyramid
represents the amount of potential food
available in each trophic level.
heterotroph
heterotrophs
autotrophs
Notice that the amount of organic matter
decreases as you move up
Vegetarians or Meat-eaters?
How many people can Earth support?
– If we are meat eaters?
– If we are vegetarian?
more people can
live on Earth
fewer people can
live on Earth