Population Ecology

Population Ecology

Vocabulary/Definitions:

• Population: All individuals of a single species which exits in the same geographical area at the same time.

Population size and dispersion:

• Population size greatly effects survivability of a species.
• Greater the population size - Better probability of the species
• Reduces effects of inbreeding
• Reduces effects of catastrophic random events.
• Population density is another important factor
• Effects probability of individuals meeting, mating and combining genetic materials.
• Population dispersion is a measure of the geographical arrangement of the individuals within a population
• 3 types
• Randomly spaced - No apparent pattern to individual locations
• Evenly spaced - Individuals are located individually according to an observable pattern
• Clumped - Small populations occur in close proximity to each other. Each group, however, is separated from similar groups

Population Growth:

• Population growth occurs as an exponential function. It is characterized by a slow initial population growth called the lag phase, followed by an explosive increase of population called the log phase.

• In a healthy ecosystem limiting factors cause the curve to reach a stable plateau. This maximum population an ecosystem can support is called the carrying capacity

In a less than healthy ecosystem the population undergoes a crash phase where toxins, disease or starvation cause a dramatic population drop.