POPULATION ECOLOGY

Population

• A group of organisms belonging to the same species, found in the same area at the same time.

Parameters of Population Ecology

1. Abundance

   • Number of individuals in a population.

2. Sex Ratio

   • Number of males to females.

3. Age Classes

   • Juvenile: Has not reached reproductive stage.

   • Adult: Has reached reproductive stage.

4. Open vs Closed Population

   • Open: Has movement of individuals (immigration/emigration).

   • Closed: No movement across boundaries (e.g., separated by barriers).

Density

• Number of individuals in a given area.

• Formula:
  Population Density
  =
  Abundance
  Area (m
  2
  
   or km
  2
  
  )
  
  
  
  
  
  Population Density=Area (m2 or km2)Abundance

Low Population Density (Low PD)

• Fewer individuals in a larger area.

• Factors:

  • Less food, water, space, mating partners, more predators.

High Population Density (High PD)

• More individuals in a smaller area.

• Factors:

  • More food, water, mating partners, fewer predators.

Artificial vs Natural Boundaries

• Artificial: Fence, globe, cage.

• Natural: River, canyon, mountain, ocean, mudslide.