5. Energy Transfer in Ecosystems 0809 WEBSITE.ppt

Biology

1. Energy Transfer in Ecosystems

2. Producers…
•Are autotrophs that convert energy entering the
ecosystem so other organisms can use it
–Ex. Plants, protists, bacteria, algae
•Most use solar energy to do photosynthesissome
use inorganic molecules to do chemosynthesis
•Producers add biomassto an ecosystem
–Biomassis all of the organic material in an ecosystem
available to organisms

3. An ecosystem is…
•All of the biotic and abiotic components of an
area
•The amount of energy an ecosystem receives
has an effect on its makeup
•All energy entering the ecosystem from the
sun or other abiotic factors needs to be
converted to be useful to other organisms

4. Amount of producers will affect the types
of consumerspresent in the ecosystem
•Consumers are heterotrophs that must eat other
organisms for nutrition
•Consumers are grouped according to their food
consumption:
–Herbivores eat producers
–Carnivores eat other consumers
–Omnivores eat both producers and consumers
–Detritivores eat wastes and parts of dead consumers and
producers. Some detritivores are decomposers
•Decomposers are bacteria and fungi that decay any living material

5. What kind of consumer?
HERBIVORE
DECOMPOSER
OMNIVORE HERBIVORE
CARNIVORE

6. All ecosystems have energy flowcaused
by organisms eating one another
•Energy flows through ecosystems from
producers to consumers
•Energy flow can be diagrammed in many
ways including:
–Ecological Pyramids
•Trophic Level Diagrams
•Energy Pyramids
–Food chains
–Food webs

7. Trophic level diagrams
•An organism’s trophic levelshows
their position in the sequence of
energy flow
•Producers belong to the 1
st
trophic
level (are most abundant)
•Herbivores belong to the 2
nd
trophic level (also called primary
consumers)
•Predators of herbivores belong to
the 3
rd
trophic level (also called
secondary consumers)
•Most ecosystems only have 3 or 4
trophic levels

8. Type of Consumer Trophic Level
•Secondary Consumer
•Primary Consumer
•Producer
• 3
• 2
• 1

9. Energy Pyramids
•Energy pyramids show how
much energy is passed from
one trophic level to the next
•On average 10% of all
energy consumed can be
passed on to the next trophic
level, but it can be as low as
1% or as high as 20%
•Most energy consumed
contributes to maintaining
homeostasis, respiration,
growth, and reproduction

10. Food Chains
•Food chains are single
pathways of energy
transfer.
•The arrows represent the
way the energy is flowing.
•So the energy is flowing
from the frog to the snake
in this food chain
•Food chains are too simple
to encompass a whole
ecosystems interactions

11. Food webs
•Food websare made of many interacting food chains.
•More accurate than food chains since most organisms feed on
more than one thing and are eaten by more than one thing
•If one part of the food web in lost there can be serious
consequences for the entire ecosystem