1. 1. What cycle is illustrated in this picture?
2. What are the key processes in the cycling of this element?
3. How could human population growth affect this cycle?

2. Population Growth Patterns and Ecological Succession
Population density is expressed as a ratio that describes a direct relationship between two quantities.
What do you think the relationship for calculating population density is?
# of individuals
Area they occupy
= population
density

3. Population Density
What might a decrease in the density of a deer population over a specific time period tell scientists about the habitat in the area?
Resources might be depleted, the community may have changed due to factors such as a new predator
Ex: If scientists sampling a population of deer counted 200 individuals in an area of 10 square kilometers, what would the density be?
20 deer/square km

4. Population Dispersion Patterns
How might individuals of a population be dispersed throughout their habitats?
What dispersion pattern is displayed in our classroom?
What dispersion pattern is displayed in the cafeteria?

5. http://video. nationalgeographic
This satellite photo shows the uniform distribution of termite mounds in Africa’s Savanna
Each mound stands at the center of floral productivity
The highly regular spatial pattern of fertile mounds generated by termites increases overall levels of ecosystem production
Termites bring coarse particles into the fine soil. The coarse particles allow water to infiltrate the soil. Also, elevated levels of nitrogen and phosphorus were found to be associated near the mounds

6. Survivorship Curves What does a survivorship curve show?
# of surviving members over time
How might it explain the reproductive strategies of a species?
Large amount of offspring, few survive / smaller amount of offspring- more parental care

7. Population Growth Patterns
Immigration
Movement of individuals into a population from another population
Emigration
Movement of individuals out of a population and into another population

8. What determines population growth?
Logistic Growth
Exponential Growth
Population growth is a function of the environment
The rate of growth is determined by the amount of resources available

9. Other Factors that Affect Population Growth
Carrying Capacity
The maximum number of individuals of a particular species that the environment can consistently support
When could carrying capacity change?
When the environment changes
What is the carrying capacity of humans?
It depends on how we use our resources

10. What factors affect the carrying capacity of an environment for a population?
Limiting Factors
Density-Dependent Limiting factors
Factors affected by the number of individuals in a given area
Competition
Predation
Parasitism/Disease
Density-Independent limiting factor
Environmental factors that limit a population’s growth regardless of the density
Unusual weather
Natural disasters
Human activities

11. What is Earth’s Carrying Capacity?

12. Ecological Succession
From clean to cluttered
A gradual process

13. Ecological Succession
After an ecosystem experiences a catastrophe and begins to re-grow, the space re-forms itself through “succession”
Succession = the sequence of biotic changes that regenerate a damaged community or create a community in a previously uninhabited area

14. Ecological Succession
Primary Succession
Establishment & development of an ecosystem in a previously uninhabited area
Ex: Glacier Bay National Park in Alaska- as glaciers recede, primary succession is observed
Begins with bare rock
“Pioneer species” are the first organisms to live in this previously uninhabited area
Typically lichens and mosses
Secondary Succession
Reestablishment of a damaged ecosystem where soil remains intact

15. Secondary Succession as a result of Fires
The Fire of 1910
Largest forest fire in American history
Burned 3 million acres across 3 states- Washington, Idaho, Montana
Almost as large as the state of Connecticut
Hot and dry summer led to 1,000 to 3,000 fires burning across these states in August
August 20th- cold front blows in and brings “hurricane” winds that turn thousands of fires into one or two “blazing infernos”
Many towns were completely destroyed by the fire
The U.S. Forest Service was shaped after this fire