The number of organisms in a population per unit area.
Change in population size over time
population size is not changing
Zero growth rate
Population will increase exponentially (J-curve)
Starts out exponential, but levels off at a certain population size (S-curve)
the maximum population size an ecosystem can support, leveling off point
reproduce fast, have many young, develop quickly. (rabbits)
reproduce steadily, have few young develop slowly. (kangaroos)
Factors that have a greater influence on population size as the population increases
Density Dependant Factors
Factors that have an impact on population size regardless of what the population size is.
Density Independent Factors
changing of plant communities
begins with bare rock from volcanic activity
begins with soil from a previous community