exam 3 pt 7 (exponential population growth -> realized niche)

exponential population growth

population increase under idealized conditions

→ dN/dT = r(N) → J-shaped curve → not realistic because not reflective of natural populations

carrying capacity

maximum population size the environment can support

logistic population growth

population under natural conditions

dN = r(N)[(K-N)/K] → S-shaped curve where plateau is carrying capacity

density-independent

birth rate + death rate do not change with population density

→

density-dependent

birth rate fall and death rate rise with population density

→

density-dependent birth and death rates are an example of what kind of feedback?

negative

→ affected by competition for resources, territoriality, disease, predation, toxic waste, and intrinsic factors

population dynamics

focuses on complex interactions between biotic and abiotic factors that cause variation in population size

metapopulation

groups of populations linked by immigration + emigration

what caused human population growth to slow down?

A) access to contraceptives

B) access to education

demographic transition

the move from the first state toward the second state

→ (high birth rate-high death rate) → (low birth rate-low death rate) leads to better conditions

what causes population growth changes in countries?

education access + healthcare access

community

a bunch of different populations interacting together

interspecific interaxtions

relationships between species

→ competition, predation, herbivory, symbiosis (parasitism, mutualism, commensalism)

interspecific competition

occurs when species compete for a resource in short supply

(-/-)

→ species 1 and species 2 spend energy in competition to get that resource

competitive exclusion

strong competition leads to a local elimination of competing species

competitive exclusion principle

states that two species competing for the same limiting resources cannot coexist in the same place

ecological niche

the total of a species’ use of biotic + abiotic resources

resource partitioning

differentiation of ecological niches, enabling similar species to coexist in a community

→ i.e. diurnal and nocturnal species

fundamental niche

all the possible area an organisms COULD occupy

realized niche

the are an organism actually occupies