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Factors of Population Size - Coggle Diagram
Factors of Population Size
types of growth
logistical growth
occurs when density-dependent factors affect pop. size over time
yields an S-shaped curve
exponential growth
number of new individuals increases with each generation but per capita growth rate stays the same
occurs in any population in which birth rate is greater than death rate
selection types
K-selection
equilibrium species; adaptive traits provide a competitive advantage when pop. size is nearing carrying capacity; tend to have large body and long generation time
r-selection
opportunistic species; maximize the per capita growth rate; short generation time and small bodies
limiting factors
density-independent
crowding does not influence likelihood of occurence/magnitude
natural disasters or weather related events affecting pop. size
denisity-dependent
degree of crowding increases= birth rates slow and death rates rise= pop. growth decreases
predation, parasitism, disease, and intraspecific competition
carrying capacity
maximum number of individuals of a species that a pop.'s environment can support indefinitely
demographic transition model stages
transitional stage
food production and health care improve
death rate drops fast and birth rate declines slowly= population growth
industrial stage
industrialization complete
birth rate declines and moves closer to death rate= slow pop. growth
preindustrial stage
pre-technology and medical advances
high birth and death rates= low growth rate
postindustrial stage
pop. growth negative with birth rate below death rate
biopic potential= theoretical rate at which the population would grow in shelter, food, and other essentials were unlimited with no pathogens or preditors