Studying Populations Flashcards
what characteristics are studied when looking at populations
size
density
dispersion
migration patterns
what letter represents size?
N
what letter represents density?
D
what methods are used with studying populations?
- survey
- sampling
- tracking
population definition
a group of individuals of one species that live in a particular area
habitat definition
the specific environment in which an organism lives characterized by biotic and abiotic factors
geographic range
the total area occupied by a population (spatial boundary)
density definition
number of individuals per unit area or volume
crude density definition
number of individuals in the total area of the habitat
ecological density definition
number of individuals in the area actually used by the individuals
types of population distribution
- clumped
- uniform
- random
random dispersion definition
an individual has an equal probability of occuring anywhere in an area
uniform definition
individuals are uniformly spaced through the environment
clumped definition
individuals live in areas of high local abundance, which are separated by areas of low abundance
what is a survey?
a count like a census
what is sampling?
taking a measurement from a portion of the population and applying it to the whole
tracking definition
monitoring / following an individual organism
what are some sampling methods?
transect
quadrat
mark-recapture
transect defintion
a straight line along which observations are made
types of transects:
point
continuous
belt
point sampling
“string is marked off at equal intervals to indicate where a count is to be taken”
continuous sampling transect
the whole area along the line is counted
resource distribution in clumped dispersion
uneven
resource abundance in clumped dispersion
abundance in the clumps
