Growth Patterns Flashcards
Biotic potential (r)
highest per capita growth rate possible
Fecundity
the ability of an organism to be fertile or to reproduce
J curve
population growth with a brief lag phase and a step increase in the growth curve
S curve
a logistic growth pattern with a lag phase, growth phase, and stationary phase in which limiting factors become significant
Exponential growth
a growth pattern exhibited by a population that doubles with each generation; results in a J-shaped curved; begins with a ag phase, followed by a steep rise
Density-independent factors
abiotic factors that limit a habitat’s carrying capacity (e.g. fire, flood, frost); the impact is not affected by the density of the population
Lag phase
the first phase of a growth graph showing little increase in population numbers
Carrying capacity (K)
the theoretical maximum population size that the environment can sustain over an extended period of time; may change as the quality of the habitat changes; the popualtion is at carrying capacity when it levels off during logistic growth
Logistic growth
a population increase resulting in a S-shaped curve; begins with slow growth, steepens to exponential growth, and then levels to a carrying capacity due to competition because of environmental resistance
Exponential phase
the second phase of a growth graph in which population size increases significantly because limiting factors are not yet significant
Density-dependent limiting factors
biotic factors that limit a habitat’s carrying capacity (e.g. parasites, disease, increase in predators, lack of water, food, or territory); the impact increases with the density of the population
Environmental resistance
the combined effects of factors that limit population growth; prevent a population from growing at its biotic potential; determine the carrying capacity of the environment
Stationary phase
the third stage of a population growth graph in when population size stabilizes because of the balance between environmental resistance and biotic potential
