Topic 8.4 - Effect of Density of Populations 𖦹⋆｡°✩ Flashcards
what affects population density in an environment
resource availability
what is population density
how close individuals within a population live near one another
when can a population become dense and what does it result in
when an abundance of food is available, can result in higher reproductive rate, limited space
when may a density of a population may decrease and what does it result in
when food is limited, lower reproductive rate, individuals can spread out in the limited space
what are density-dependent factors
abiotic or biotic factors whose effect on population size relies on a population’s density
what are examples of density-dependent factors
༻ competition for resources
༻ territoriality
༻ disease
༻ predation
what are density-independent factors
abiotic/biotic factors that affect population size regardless of population density
what are examples of density-independent factors
༻ natural disasters (ex. floods, forest fires, volcanic eruptions)
༻ pollution
what is a logistic-growth model
describes population growth that initially starts slowly, immediately followed by exponential growth and ends with a relatively stable maximum growth
what shape is a logistic-growth model
an S-shaped curve
what is the carrying capacity
the maximum number of individuals in an environment can sustain. both density dependent and density independent factors can cause a population to reach carrying capacity
when can a population temporarily exceed carrying capacity
under certain conditions, but limiting factors will always bring population size back down
where will fluctuations in population size occur
can naturally occur at or near carrying capacity
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