POPULATION DYNAMICS
I.
Populations are defined in several ways
a. POPULATION  a group of individuals of a single species
that occupy the same general area
b. POPULATION ECOLOGY  concerned with the changes in
population size and the factors that regulate populations over
time
II.
Density and dispersion patterns are important population variables
a. POPULATION DENSITY  the number of individuals of a
species per unit area or volume
b. Impossible to count all the individuals so scientists use various
sampling techniques
i. MARK-RECAPTURE METHOD
c. DISPERSION PATTERN  refers to the way individuals are
spaced within their area
d. CLUMPED  individuals are aggregated in patches
e. UNIFORM  even spread
f. RANDOM  spaced in patternless, unpredictable way
III.
Idealized models help us understand population growth
a. EXPONENTIAL GROWHT MODEL  rate of expansion of a
population under ideal conditions; unregulated growth
b. Population-limiting factors and the logistic growth model
i. POPULATION-LIMITING FACTORS 
environmental factors that restrict population growth
ii. LOGISTIC GROWTH MODEL  idealized population
growth that is slowed by limiting factors as the
population size increases
1. CARRYING CAPACITY  the maximum
population size that an environment can support at
a particular time with no degradation to the habitat
IV.
Multiple factors may limit population growth
a. Competition for limited resources
i. Ex. Food, territory
b. Increased disease transmission
c. Physiological factors are impacted by dense populations
d. Abiotic factors may impact population size
V.
Some populations have “boom-and-bust” cycles
a. Not fully understood why this occurs in nature
VI.
Life tables track mortality and survivorship in populations
a. SURVIVORSHIP CURVES  plot the proportion of
individuals alive at each age
VII. Evolution shapes life history
a. LIFE HISTORY  the series of events from birth through
reproduction and death
VIII. The human population has been growing exponentially for
centuries
a. Human population was 1 billion in 1850, now it is over 6
billion
IX.
Birth and death rates and age structure affect population growth
a. Zero Population Growth (ZPG) is when birth rates equal death
rates
b. AGE STRUCTURE  the proportion of individuals in
different age-groups
X.
Principles of population ecology have practical applications
a. RENEWABLE RESOURCE MANAGEMENT  harvesting
crops without damaging the resource
b. MAXIMUM SUSTAINED YIELD  harvesting at a level that
produces a consistent yield without damaging the population