Transcript Envir100Lect5Feb8

Top Carnivore - Friend or Foe
Review where we are in the course
Link to Wednesday lecture
Exponential vs. linear growth
Explore: Top Carnivore: Friend or Foe
Food chains
Food Webs
Bioaccumulation
Competitor or friend of conservation
Readings: Yellowstone Story
Lecture on Conservation
Concept of Shrinking Expectations
Course Context
Population
Air Resources
Water Resources
Earth Systems
• Biosphere
• Hydrosphere
• Lithosphere
• Atmosphere
Ecosystem Resources
e.g., forests
Other (Non- Renewable)
Resources
e.g., oil
(# people)
I. = P.A.T.
Affluence
(GDP/person)
Technology
(tons CO2/GDP)
• Very simple diagram
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 tax
Cars blamed for global warming; Eyman fires back
By BRIAN SLODYSKO
P-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)
0%
0%
1. $0.01, $0.02,
$0.04, $0.08,
etc.
2. $100.00,
$100.00,
$100.00,
$100.00
1
Answer Now!
2
10
Outcome
Summer Job
Accumulative Income
12000
Linear ($100)
Exponential
10000
8000
6000
4000
2000
0
0
5
10
15
20
Work Days
• Day 20: $100 person = $2000 ($100)
• Day 20: Penny person = $10,486 ($5243)
• Day 50: 11.259 trillion dollars
Billions
World Population (est.), -10,000 to 2300
Tom Hinckley
1968
10 Not freaking
out
9
8
7
2000
6
5
1975
4
3
1950
1900
1850
1800
2
1
0
-10000
1968: Garrett
Hardin freaks
out
-7500
-5000
-2500
0
2500
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
Illustration/Reference
Growth/Time 0 1 2
3
4
5
6
7
8
9
10
16
18
20
22
Linear
2 4 6 8
Exponential
2 4 8 16 32 64 128 256 512 1024
10 12 14
2048
With each time interval:
Linear: increases by 2 (+ 2)
Exponential: doubles (*2)
Population Growth: Has been exponential
Population Growth is a function of a number of parameters
http://www.watersfoundation.org/index.cfm?fuseaction=home.main
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?
• 99th day
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
Top Carnivores
Omnivores
Detritus or
Decomposition
Chain
Herbivores
1 - 5%
Producers
Compounds from
Biogeochemical
cycles
• Very simple diagram • Connections
between levels:
• 10% rule
chain or web
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
Foe
“Killing sea lions will not save Columbia River salmon”
By John Balzar
Special to The Times
February 7, 2008
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 1926
2. Beavers returned after wolves
returned
3. Elk browsing increases aspens &
willows
4. Rivers became incised with elk
browsing
5. 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
Historical
Condition
or state
Current
Condition
or state
Future
Condition
or state
Russell
Jim