8.3: Population Density Flashcards
What is a population?
- a group of individuals of the same species living in an area
What is population ecology?
- analyzes the factors that affect population size and how and why it changes over time
What is density?
The number of individuals per unit area
How can density be determined by? (2)
- Counting the number of individuals (rarely done)
- sampling techniques (count small areas, average the areas, then use the averages to estimate the total population size)
Why is knowing a population’s density beneficial?
It provides more information about its relationship to the resources it uses
Why do species with large body sizes generally have lower population densities than species with smaller bodies?
- each large organism consumes more of the available resources
What is dispersion?
The pattern of spacing among individuals within a population
What are the three types of dispersion?
Clumped, uniform, and random
What is clumped dispersion?
Individuals gather in patches
What is uniform dispersion? What can it be due to? (2)
- evenly spaced individuals in a population
- can be due to territoriality
What is random dispersion?
Unpredictable spacing, not common
The size of a population is not ___. It can be affected by? (3)
- static
- birth/death
- immigration/ emigration
