Transcript How Does Energy Move Through Ecosystems?

Energy:
Movement In Ecosystems
Yellowstone Wolves Case Study
He’s Tagged!
Reintroduced into the park in
1995…stolen from Canada!
They eat deer…
And elk…
And horse…
And lamb…
And cow…
So…
“I went
fishing and
all I caught
was this
stupid
wolf”
Why is it environmentally
harmful to remove top
predators like the wolf?
Discuss with your partner
and make a list.
Elimination of Top Predators…
• No more leftover carrion to feed
scavengers (vultures, bears, ravens)
Elimination of Top Predators…
• No more controlling populations of lower
organisms on food chain
Elimination of Top Predators…
• Loss of stability in food web
Elimination of Top Predators…
• Grass/vegetation habitat decreases
Elimination of Top Predators…
• Increase in soil erosion/compaction
Energy Flow in Ecosystems
Producers
Consumers
Decomposers
Producers: Phototrophs
• Use sun to produce sugar(photosynthesis)
• Plants, Algae (Phytoplankton), Bacteria
• PS is 1 % efficient!
Producers: Chemotrophs
• Use H2S to produce sugars
(chemosynthesis)
• Bacteria
Producers: Chemotrophs
Consumers: Heterotrophs
• Break down stored sugars (aerobic
respiration)
• C6H1206 + 6H2O + 6O2 ----> 6CO2
+12H2O+ Energy
Consumers: Heterotrophs
DEER!
• Primary Consumers: Herbivores, eat
producers
Consumers: Heterotrophs
• Secondary Consumers: Carnivores,
eat primary consumers
Consumers: Heterotrophs
Great White
• Tertiary Consumers: Eat secondary
consumers, top, apex predators
Decomposers: Saprotrophs
• Feed off dead organic © matter in
soil, release nutrients.
• Fungi and Bacteria
Importance of Decomposers
1. Make vital
elements available
to primary
producers.
 Convert organic
material into
inorganic materials
that producers can
use in soil or
water.
Chains vs Webs
• Simple vs Complex
• Trophic Levels: Energy flows from
one trophic level to another
Simpson’s FOOD WEB
FOOD WEBS
• Show multiple
ways energy can
move through an
ecosystem
• More
connections,
more stable in a
changed
environment
Bu-Bye Energy!
• Orgs are not 100% efficient
• Only 10% of energy at 1 level makes
it to the next level (90% lost as heat)
Heat Energy Loss
Less energy as you go up = no more than 3-4
levels in a food chain
Pyramid of Numbers
• Shows # of indiv. at each
trophic level
Pyramid of Biomass
Biomass: Mass of organic material
• Not a typical pyramid shape
• Consumers may eat most of
producers as they are made
Pyramid of Energy
• Always a pyramid shape
• Energy lost as you go 10% rule
So, Why Should We All Be
Vegetarians?
Go Blank!
Gross Primary Productivity (GPP)
• Rate at which energy is captured
during PS
LOW
HIGH
Net Primary Productivity (NPP)
• Energy that
remains in
plants after
respiration;
available to
consumers
• NPP= GPP
-- Resp.
What Ecosystems Have High NPP?
• Per unit area: