Download Unit 2: Ecology Content Outline: Population Ecology (2.2)

Unit 2: Ecology
Content Outline: Population Ecology (2.2) - Part 1
I.
Population Ecology
A. Population – This is the same species, at the same time, in the same place, and reproducing.
B. Density – This term refers to the number of organisms in a given area.
C. Dispersion – This term refers to the pattern of organisms within a given area.
1. Clumped – This pattern results from a need for nutrients, water, or some other important items.
2. Uniform – This pattern results from territoriality or favorable environment.
3. Random – There is no apparent reason or pattern.
II. Demography - the study of population sizes and distribution
A. Growth – Populations grow in number by birth or immigration (going into an area).
B Decline – Populations decrease in number by death or emigration (leaving an area).
C. Calculating percentage population change:
Percent change = change in population X 100 %
Total population size
III. Population Limiting Factors
A. Resources - food, water, space, jobs, etc.
1. As resources become scarce competition rises and population numbers decrease.
B. Health Conditions - crowding and disease
C. Predation by another species
1. Predator-prey relationships
a. Prey - organism killed and eaten by another organism
b. Predator - organism that eats all or part of another organism after killing it.
D. Carrying Capacity
1. This term refers to the largest population that an environment can support at any given time.