1. Carrying Capacity
The number of individuals who can be supported in a given area within natural resource limits, and without degrading the natural environment.
The carrying capacity for any given area is not fixed.
As the environment is degraded, carrying capacity actually shrinks
Limiting factors: food availability, competition, harsh winter, etc.

2. Carrying Capacities
If the population # goes above the carrying capacity = organisms die (not enough resources)
•If the popluation# is below the carrying capacity = more births (abundant resources)

3. Limiting Factors
a resource or environmental condition which limits the growth, distribution or abundance of an organism or population within an ecosystem. 

4. Types of Limiting Factors
1. Density Dependent
2. Density Independent

5. Density Dependent Limiting Factors
Operate ONLY when the population reaches a certain level.
Operate more strongly when a population is large and dense
Examples
Competition
Predation
Parasitism
Disease

6. Density Independent Factors
Factors that affect all populations in similar ways, regardless of population size.
Examples
Unusual weather
Natural disasters
Seasonal cycles
Certain human activities such as clear cutting forests

7. Growth Curves J-Curve= population size grows more rapidly over time.
Also known as exponential growth
Not realistic.
Assumes resources are always plentiful

8. Growth Curves
• S-Curve= population size grows until it reaches carrying capacity.
Realistic in nature.
Assumes resources are limited.