energy: movement in ecosystems. yellowstone wolves case study
TRANSCRIPT
Energy: Movement In Ecosystems
Yellowstone Wolves Case Study
Reintroduced into the park in 1995…stolen from Canada!
He’s Tagged!
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!
• Use H2S to produce sugars (chemosynthesis)
• Bacteria
Producers: Chemotrophs
Producers: Chemotrophs
Consumers: Heterotrophs
• Break down stored sugars (aerobic respiration)
• C6H1206 + 6H2O + 6O2 ----> 6CO2
+12H2O+ Energy
Consumers: Heterotrophs
• Primary Consumers: Herbivores, eat producers
DE
ER
!
Consumers: Heterotrophs
• Secondary Consumers: Carnivores, eat primary consumers
Consumers: Heterotrophs
• Tertiary Consumers: Eat secondary consumers, top, apex predators
Great W
hite
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 LossLess 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
Biomass: Mass of organic material
• Not a typical pyramid shape• Consumers may eat most of
producers as they are made
Pyramid of Biomass
• Always a pyramid shape• Energy lost as you go 10% rule
Pyramid of Energy
So, Why Should We All Be Vegetarians?
Go
Blan
k!
Gross Primary Productivity (GPP)
• Rate at which energy is captured during PS
HIGH
LOW
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:
