lots of variation different species' populations fluctuates over time
·
in how
>
-
population ecology =
study of factors that drive changes in population size
·
promote + limit growth
53 1 .
Populations have particular characteristics
population all individuals of a species living within a given area
·
-
Population Mark-and-recapture technique used to estimate the size of a population that's very large inhabiting an expansive area
·
-
or
i
Size
Density ·
N =
(2) XM
N =
population size
C = Total number of individuals caught
R =
Number of recaptures
M = Number of individuals marked previously
·
number of individuals in a given area
Population density =
size of area
-helps determine if a population is densely crowded/scarce compared to other populations
helps scientists know if a species has enough resources in its area+ set for how
many organisms
·
regulations can
be harvested
Population geographic range area over which a population is spread
·
-
Range's
Distribution >
-
determined by favorable conditions + access for species
sometimes new species are accidentally introduced to a new continent >
-
species' required biotic + abiotic conditions help
predict where species will spread
·
population distribution -
measure of how individuals are clumped within their
geographic range
·
random uniform ,, or clumped
>
-
random distribution -
no pattern in where individuals are relative to other individuals
evenly spaced
>
-
uniform distribution -
individuals are out
>
-
clumped distribution -
individuals aggregate
>
-
usually in response to clumped resources or social behavior
Population Population sex ratio ratio of males to females
·
-
sex ratio
is age >
-
usually 50 : 50 but can
,
vary
structure
uneven sex ratios can impact number of offspring and therefore how rapidly populations grow
population age structure number of individuals in different age categories
·
-
>
- effects number of offspring +
population growth
·
in how
>
-
population ecology =
study of factors that drive changes in population size
·
promote + limit growth
53 1 .
Populations have particular characteristics
population all individuals of a species living within a given area
·
-
Population Mark-and-recapture technique used to estimate the size of a population that's very large inhabiting an expansive area
·
-
or
i
Size
Density ·
N =
(2) XM
N =
population size
C = Total number of individuals caught
R =
Number of recaptures
M = Number of individuals marked previously
·
number of individuals in a given area
Population density =
size of area
-helps determine if a population is densely crowded/scarce compared to other populations
helps scientists know if a species has enough resources in its area+ set for how
many organisms
·
regulations can
be harvested
Population geographic range area over which a population is spread
·
-
Range's
Distribution >
-
determined by favorable conditions + access for species
sometimes new species are accidentally introduced to a new continent >
-
species' required biotic + abiotic conditions help
predict where species will spread
·
population distribution -
measure of how individuals are clumped within their
geographic range
·
random uniform ,, or clumped
>
-
random distribution -
no pattern in where individuals are relative to other individuals
evenly spaced
>
-
uniform distribution -
individuals are out
>
-
clumped distribution -
individuals aggregate
>
-
usually in response to clumped resources or social behavior
Population Population sex ratio ratio of males to females
·
-
sex ratio
is age >
-
usually 50 : 50 but can
,
vary
structure
uneven sex ratios can impact number of offspring and therefore how rapidly populations grow
population age structure number of individuals in different age categories
·
-
>
- effects number of offspring +
population growth
