2. Lake Victoria
Freshwater lake in Africa
Formerly home to ≈ 400 species of cichlids
1960: Nile perch
introduced
1990: water hyacinth
invaded
Today, ecological
imbalance; why?
3. What Is Ecology?
Literally study of one’s “house”
Interactions
Two components
Biotic
Abiotic
Broadest biological field of study
5. Goals Of Ecologists
Understand how ecosystems function
Make connections: landscape ecology
Connections among ecosystems
Great blue heron
6. Energy
Capacity or ability to do work
Flows through ecosystems
Why do organisms need energy?
Different kinds
Potential energy Kinetic energy
7. First Law of Thermodynamics
Energy cannot be
created or
destroyed
Energy can be
changed from one
form to another
8. Second Law of
Thermodynamics
When energy is changed from one form
to another, some is degraded into heat
Heat is a less usable form of energy
Increases entropy in the universe
10. Producers
Make their own food
Photosynthesis
Examples?
Lii
L
gh
gh
tt e
enne
errg
gyy
6CO2 + 6H2O + ------> C6H12O6 + 6O2
11. Consumers
Feed on other things
Herbivores
Carnivores
Omnivores
Detrivores
12. Decomposers
Break down dead organisms and waste
products
Examples?
13. Energy Flow
Energy passes from one organism to the
next
Trophic level: each step in this flow of
energy
Food chain: straight path
Food web
Interconnected food chains
More realistic than food chain; why?
17. Carbon Cycle
Essential component for life
Gas (CO2) in atmosphere
Several forms in ocean
Can take a long time—think fossil fuels
Photosynthesis Cellular respiration
CO2 Sugar CO2
25. Phosphorus Cycle
No atmospheric component
Phosphates used in DNA and ATP
(chemical energy)
Phosphates move through the food chain
Land Organism Organism Land
30. Species Interactions
No species lives in complete isolation
Symbiosis
Intimate relationship between members
of at least 2 species
Mutualism, commensalism, parasitism
Result of coevolution
Other interactions
Predation, competition
34. Species Interactions
Predation: consumption of one species by
another
Coevolution: “arms race”
35. Avoiding Predators
Mechanical defenses
Social groups
Camouflage
Protective chemicals
36. Species Interactions
Competition: two or more organisms
attempting to use the same resource
Intraspecific vs. interspecific
37. Keystone Species
Crucial to maintenance of an ecosystem
Loss affects many other
species
Examples?
This idea is being
challenged; why?
38. Case Study:
Global Climate Change
Atmospheric CO2 increased dramatically.
Why?
10 warmest years have occurred since 1990
2005 warmest
1998 second warmest
2002 third warmest
Earth’s temperatures may rise 1.8o – 4.0o C
(3.2o – 7.2o F) by end of 21st century
What could occur?
39. Case Study:
Global Climate Change
Kyoto Protocol – International climate change conference
– Kyoto, Japan 1997
Highly developed countries to cut
CO2 emissions ~ 5.2% by 2012
US Department of Energy
Automotive vehicles
designed for better gas
mileage
High efficiency wind
turbines