9- regulated population growth

carrying capacity (K)

the number of individuals an environment can support

population control/regulator

a factor that limits population size

density-dependence negative

individuals reproduce better when density is low. growth rate slows as density increases

density-dependence positive

individuals reproduce better when density is high. growth rate increases as density increases

density independence

environmental factors that affects population size regardless of population’s density

logistic growth model

population growth rate slows as it approaches K

disturbance

event that disrupts an ecosystem or community by altering its structure, composition, or resource availability

stable equilibrium

a state where an ecosystem maintains its balance and can return to that state after a disturbance

oscillation

interactions between populations of at least two different species (doesn’t stabilize)

life history

the pattern of survival and reproduction events

trade-offs

a situation where improving one aspect of an organism or ecosystem comes at the expense of another aspect

semelparity

reproduction once per lifetime. LOTS of babies

iteroparity

repeated reproduction throughout lifetime. Less but good quality babies

fast (r-selected) life history

short lives and many small offspring with little parental care. Resources are plentiful, higher amount of babies

slow (K-selected) life history

long lived and fewer, larger offspring. Lots of parental care and emphasize quality because resources are scarce

how is logistic similar and different to geometric growth?

both use discrete time. geometic doesnt have K

what 5 factors describe a species’ life history?

age at 1st reproduction, energy allocated per offspring, # offspring per event, frequency of reproduction, life span.