AP Environmental Science

age-structure pyramids
graphical representations of population’ ages
albedo
the fraction of solar energy that is reflected back into space
biotic potential
the amount that the population would grow if there were unlimited resources in its environment
birth rate (crude birth rate)
the number of live births per 1000 members of the population in a year
carrying capacity
the maximum population size that can be supported by the available resources in a region
death rate (crude death rate)
is equal to the number of deaths per 1000 members of the population in a year
demographic transition model
a model that is used to predict population trends based on the birth and death rates as well as economic status of a population
ecological footprint
the amount of the earth’s surface that is required to supply the needs of and dispose of the waste from a particular population
emigration
the movement of individuals out of a population
genetic drift
the random fluctuations in the frequency of the appearance of a gene in a small isolated population, presumably owing to chance, rather than natural selction
immigration
the movement of individuals into a population
k-selected
organisms that reproduce later in life, produce fewer offspring, and devote significant time and energy to the nurturing of their offspring
logistic population growth
when a population is well below the size dictated by the carrying capacity of its region, it will grow exponentially, but as it approaches the carrying capacity, its growth rate will decrease and the size of the population will eventually become stable
population density
the number of individuals of a population that inhabit a certain unit of land or water area
replacement birth rate
the number of children a couple must have in order to replace themselves in a population
r-selected
organisms that reproduce early in life and often have a high capacity for reproductive growth
total fertility rate
the number of children an average woman will bear during her lifetime; this information is based on an analysis of data from preceding years in the population question
growth rate equation
(birth rate – death rate) / 10
IPAT equation
I= PxAxT
where:
P=population size
A=affluence
T=level of technology