population ecology

allee effect

a positive correlation between population size and per capita population growth rate

abiotic

non-biological, EX: weather, soil structure, water availability, light availability, altitude, pH, available nutrients and minerals

biotic

living, EX: bacteria, fungi, plants, animals

carrying capacity, K

the maximum number of individuals that its environment can sustainably support

demography

the study of population structure and dynamics

demographic transition

As a society develops and industrializes, its population transitions from having high birth and death rates to low birth and death rates.

density dependence

the impact on population dynamics changes with the size of the population EX: disease, competition for food, parasitism, and predation

density independence

the impact on population dynamics does not change with the size of the population EX: storms, fires, volcanoes, and floods

dispersal

the movement of individuals away from a group of others of the same species

emigration

the movement of living individuals out of a population

immigration

the movement of individuals into a population or area

finite rate of growth (lambda)

the population size at one time step to the size of the population at the previous time step

intrinsic rate of increase (r )

the growth rate, per individual per unit time, for an equivalent population with no resource limitation

logistic growth

the population experiences continuous reproduction and limited resources

geometric growth

a growth model for populations with discrete reproduction and unlimited resources

exponential growth

maintains a constant per capita growth rate equal to its intrinsic rate of growth, r

mortality

the number of deaths per unit time occurring within that population

survivorship

the probability of an individual surviving to a particular age

population

a group of individuals of the same species living within a defined area at the same time