Chapter 51 (exam 4) Flashcards
what two factors determine range
- abiotic factors
- biotic factors
population density
number of individuals per unit area
what are the different arrangement of patterns within populations
- random
- clumped
- uniform
random
position of each individual is independent of the others
clumped
organisms associate in social groups or quality of habitat is patchy
uniform
negative interactions occur among individuals (competition)
metapopulation
population made up of many small, physically isolated populations connect by dispersal
the number of individuals present in a population depends on what four processes
- birth
- death
- immigration
- emigration
what is the difference between immigration and emigration
immigration is when individuals enter a population from another population while emigration is when individuals leave a population to join another
what is a life table
summarizes probability that an individual will survive and reproduce in any given time interval over course of its lifetime
what are the types of survivorship curves
- type 1: survivorship high thru life and drops drastically in old age
- type 2: have same probability of dying in each year of life
- type 3: extremely high death rates
fecundity
number of female offspring produced by each female in the population
what does net reproductive rate indicate
whether the population is increasing or decreasing
how to find populations overall growth
change in population size (deltaN)/per unit time (deltat)
exponential growth
- no immigration or emigration is occurring
- per capita growth rate is constant and density independent
- accelerating increase in size of population
per rate capita of increase (r)
difference between the birth rate and death rate per individual
birth>death then
r>0
- population growing
birth<death then
r<0
- population declining
r=0
population size does not change
intrinsic rate of increase
- rate of increase of a pop. when conditions are ideal
- birth rates as high as possible
- death rates as low as possible
what do the graphs of exponential growth usually look like
J shaped
exponential growth is…
density independent
- pop. size does not limit growth
what are the two types of circumstances in exponential growth
- colonization of new habitat
- recovery after a disaster
density dependent
referring to any characteristic that varies depending on population density
carrying capacity (K)
maximum number of individuals in a population that can be supported in a particular habitat over a sustained period of time
will population grow if N is below K
yes
Logisitic growth equation
dN/dt=rN|K-N/K|
as a population approaches a habitat’s carrying capacity what happens to growth
predicted to slow
Logisitic population growth
- decrease in growth as a pop. size approaches the carrying capacity
- density dependent
what kind of shape does logistic growth represent
S shaped
what two types of factors regulate pop. sizes
- density independent factors (usually changes in abiotic environment)
- density dependent factors (usually biotic)
density dependent factors
limit pop. size
- competition for resources
- disease and parasitism
- predation
- toxic wastes
- social behavior
intraspecific
within species interactions
interspecific
between species interactions
what does age structure drastically impact
influences the population’s growth over time
replacement rate
average fertility required for each women to produce exactly enough offspring to replace herself and offsprings father
