1. Ecosystems and communities

2. Weather and Climate Weather Climate
Day-to-Day variations in conditions
Climate
Year-after-Year patterns of temperature and precipitation
Factors that affect CLIMATE?

3. The Greenhouse Effect Greenhouse Gases Why is this important?
Carbon Dioxide, Methane, Water Vapor, CFCs
Why is this important?

4. Where do Organisms Live?
Tolerance: the range of conditions under which an organism can survive and reproduce.
Habitat: the general place where an organism lives
Niche: An organism’s role in an ecosystem, including how it interacts with biotic and abiotic factors, plus the resources it uses

5. Competition in Ecosystems
Definition: When organisms attempt to use the same resource
Intraspecific – between members of the same species
Interspecific – between members of different species
Competitive Exclusion Principle
No two species can occupy exactly the same niche at the same time
If two species attempt to occupy the same niche at the same time, one will lose out

6. Predation and Herbivory
Predation: One animal (predator) captures and feed on another animal (prey)
Herbivory: One animal (herbivore) feeds on primary producers (i.e. plants)
*BOTH affect the population size and distribution of what is eaten
What is going on here??

7. Keystone Species
Definition: A species that can cause dramatic changes in ecosystem and/or community structure

8. Symbiosis
Definition: Relationship in which 2 organisms live closely together
Types: Mutualism, Parasitism, Commensalism
Mutualism: Both organisms benefit
Parasitism: One organism benefits and the other is harmed
Commensalism: One organism benefits and the other is unaffected

9. Is it Mutualism, Parasitism, or Commensalism?
Clownfish and Sea Anemone
Tick and Human
Caterpillar and Wasp (larvae)
Ants and Acacia
Whale and Barnacles

10. Populations

11. Describing Populations
Geographic Range: Area inhabited by population
Density: Number of individuals per unit area
Distribution: How individuals are spaced within a population
Random Uniform Clumped
Growth Rate: population numbers changing
Age Structure: Number of males and females of each age
Why is this important?

12. Random, Uniform, or Clumped??

13. Population Growth Rate
What factors affect growth rate??
Birthrate
Death rate
Immigration
Emigration

14. Exponential Growth
Definition: The larger a population gets, the faster it grows
When does this occur?
Under ideal conditions, unlimited resources

15. Logistic Growth
Definition: When a population’s growth slows and then stops, following a period of exponential growth.
Carrying Capacity: The maximum number of individuals of a species that a particular environment can support

16. Limiting Factors
Definition: Factors that control the growth of a population and
determine the carrying capacity
Density-Dependent Factors: Affect populations
significantly only when population reaches a certain size
Density-Independent Factors: Affect all populations in
similar ways, regardless of size and density