Download What is population ecology? - Mrs. Cindy Williams Biology website

What is population ecology?
Population Ecology
• the study of how plant and animal
populations within a community affect each
other
• What affect population ecology?
• density
• age
• distribution
• growth
• competition
• predation
Population Density
• the measure of how crowded organisms are
in their environment
• organisms compete for resources, keeping a
balance is important
If the population is too high, some
organisms will __________.
Age
• a population can be classified by its age
• 3 groups of age classes are
1. preproductive – young and have not
reproduced
2. reproductive – in the process of reproducing
3. postproductive – past the stage of reproducing
To be productive, a community
should contain each of these three
age groups.
Distribution
• a description of how organisms are
distributed within their community
Population Growth
• increase in the number of organisms who
inhabit an area
• population growth is determined by
1. immigration – the act of an organism
moving into a habitat
2. emigration – the act of an organism
moving out of a habitat
3. natality – the production of new
individuals in a habitat (birth rate)
4. mortality – the death rate in a population
Increasing, Decreasing, or Stays the Same…
# of immigrants > # of emigrants
# of immigrants = # of mortalities
# of natalities < # of mortalities
# of immigrants + # of emigrants = # of
natalities + # of mortalities
Competition
• the use of the same resources by different
organisms to live
• What are the 3 major limiting resources for
animals?
food, shelter, and water
• What are the 3 major limiting resources for
plants?
nutrients, sunlight, and water
Predation
• one living organism serving as food for
another organism
Carrying Capacity
• the maximum population size of the species that the
environment can sustain indefinitely, given the food, habitat,
water and other necessities available in the environment
Predator-Prey Graph