Top Carnivore - Friend or Foe

Review where we are in the courseLink to Wednesday lecture

Exponential vs. linear growthExplore: Top Carnivore: Friend or Foe

Food chainsFood WebsBioaccumulationCompetitor or friend of conservation

Readings: Yellowstone StoryLecture on Conservation

Concept of Shrinking Expectations

Course Context

• Very simple diagram

Earth Systems• Biosphere• Hydrosphere• Lithosphere• Atmosphere

Air ResourcesWater Resources

Ecosystem Resourcese.g., forests

Other (Non- Renewable) Resourcese.g., oil

I. = P.A.T.

Population(# people)

Affluence(GDP/person)Technology(tons CO2/GDP)

Yoram’s Final Two Statements“I am a technology realist”

“That is why I think a carbon tax is needed”

Vehicle fuel efficiency is target of proposed taxVehicle fuel efficiency is target of proposed taxCars blamed for global warming; Eyman fires back

By BRIAN SLODYSKOP-I REPORTER

February 7, 2008

OLYMPIA -- Seattle Mayor Greg Nickels and Sen. Ed Murray, D-Seattle, want car owners to warm to the inconvenient truth of cutting vehicle emissions.

Pick an option for your summer job (50 days)

1 2

0%0%

1. $0.01, $0.02, $0.04, $0.08, etc.

2. $100.00, $100.00, $100.00, $100.00

Answer Now! 10

• Day 20: Penny person = $10,486 ($5243)• Day 50: 11.259 trillion dollars

Outcome

• Day 20: $100 person = $2000 ($100)

World Population (est.), -10,000 to 2300

0

1

2

3

4

5

6

7

8

9

10

-10000 -7500 -5000 -2500 0 2500

Billions

18501900

1800

1950

1975

2000

1968: Garrett Hardin freaks out

Tom Hinckley 1968 Not freaking out

Linear vs. exponential growth (or decay)

• Exponential: Nt = Noekt

• No - initial quantity• t - time• Nt - quantity after time to

• k - constant• e - exponential function (e is the base of the

natural log)

• Linear: Nt = N0*t

http://lectureonline.cl.msu.edu/~mmp/applist/decay/decay.htm

Growth/Time 0 1 2 3 4 5 6 7 8 9 10Linear 2 4 6 8 10 12 14 16 18 20 22Exponential 2 4 8 16 32 64 128 256 512 1024 2048

Illustration/Reference

http://www.watersfoundation.org/index.cfm?fuseaction=home.main

Population Growth: Has been exponential

Population Growth is a function of a number of parameters

With each time interval:Linear: increases by 2 (+ 2)Exponential: doubles (*2)

• 99th day

The parable of the lily pond: a test

• If lilies growing in a pond double every day, and on the 100th day they cover the whole pond, on what day do they cover half of the pond?

Food Chains, Food Webs, Trophic Levels, Bioaccumulation

• Obey 1st & 2nd laws of Thermodynamics– Energy cannot be created or destroyed;

only its form can change.– Conversion of energy is inefficient

• Main source of energy is the sun.• Role of biogeochemical cycles.

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/FoodChains.html

Trophic Pyramid

• Very simple diagram• 10% rule

Herbivores

Omnivores

Top CarnivoresDetritus or DecompositionChain

• Connections between levels: chain or web

Compounds from Biogeochemical

cycles

Producers

1 - 5%

Food Web Example

Bioaccumulation• As a consequence of energy flow through

a food chain (i.e., you must eat a lot!), certain compounds can accumulate.

• Examples– Fat soluble compounds

• DDT• Tetra-ethyl lead• Methyl mercury• Dioxin• PCBs

160

19

10

8.00001

Top Carnivores: Friend or Foe

““Killing sea lions will not save Columbia River salmon”Killing sea lions will not save Columbia River salmon”By John Balzar

Special to The TimesFebruary 7, 2008

Foe

Friend• Reading for Today• Wolves in Yellowstone & Cougars in Zion N Park• Grizzly or wolf as an umbrella species

Foe

• Shared space• Status• Fear• Competition

• Food• Space

• Example with sea lions

Which of the following statements is false.

0%

0%

0%

0%

0% 1. Wolves were extirpated in 19262. Beavers returned after wolves

returned3. Elk browsing increases aspens &

willows4. Rivers became incised with elk

browsing5. Wolves are carnivores & predators

Answer Now! 10

Impact is a trophic cascade!

http://www.forestry.oregonstate.edu/aspen/

Visuals

W.J. Ripple photographs, OSU

Impact is a trophic cascade!

Zion National Park, Utah

Summary: Top Carnivores

• Exponential vs. linear changes• First and second laws of thermodynamics• Energy from the sun• Biogeochemical Cycles• Food chains, webs, trophic cascades,

bioaccumulation• Foundation for Conservation Biology• Fundamental changes in how we think!

Concept of Shrinking Expectations

Current Condition or state

Future Condition or state

Historical Condition or state

Russell Jim