population Flashcards
why does age structure have a profound effect on population growth?
reproductive capacity varies with age
What is a clumped dispersion pattern
If you find an individual in one location, there is a higher probability of finding an individual in a neighbouring region
What is a regular dispersion pattern?
If you find an individual in one location, there is a lower probability of finding an individual in a neighbouring region
What is a random dispersion pattern?
Equal probability of finding an individual at any point within the region
Spatial variation in environmental conditions strongly influence
dispersion patterns
give an example of interactions which promote clumped dispersion patterns
social lives
give an example of interactions which promote regular dispersion patterns
food, space and mate competition
What are demographic eveents?
pop = births - deaths + immigration - emigration
What can be used to determine growth rates and keep track of demographic factors?
Life table
A cohort table follows _
Individuals of a species born in the same rime frame across entire llife span
Horizontal life tables follow _
species across lifespan
Vertical life tables look at _
a sample of a population at a single time
What does the fecundity schedule keep track of?
number of offspring produced by females within given timespan
age dependant tables look _
across discrete calendar time frames
stage dependant tables look _
at important stages in organisms life cycle
Describe type 1 survivorship curve
high parental care, high adult survivorship, lower fecundity
Describe type 2 survivorship curve
constant survivorship throughout lifespan
Describe type 3 survivorship curve
low juvenile survivorship, low parental care, high fecundity
What is an organisms life history strategy?
How it allocates resources to be put towards growth, maintenance and reproduction
what is r
intrinsic growth rate
which life history traits are influenced by environmental conditions the most?
age of first reproduction
number of broods per female
number of offspring per brood
semelparous organisms
reproduce only once per lifespan
iteroparous organisms
reproduce multiple times over lifespan
what is the big bang in semelparous organisms?
Large number of offspring produced per brood (only one)
What effect can select for early and frequent reproduction?
Predation
the carrying capacity k represents
the maximum number of individuals that can be sustained by the resources within an environment
what kind of growth does a carrying capacity cause?
logistic growth
give 3 density dependant factors which limit pop growth
predation
food supply
pathogens
give a density independent factor
extreme weather conditions
unpredictable habitats are associated with
high fecundity and high r
predictable habitats are associated with
low fecundity/r, high probability of reproductive success
r-strategists employ strategies which
allow for high intrinsic growth rates
k-strategists employ strategies which allow for
persistence near carrying capacities
species that use abundant resources _
reach higher population densities
species with smaller body sizes _
reach higher population densities
species which have complex social organisations _
reach high population densities
species newly introduced to a region can _
reach higher population densities
organisms live in distinct habitat _
patches
a _population may be divided in to _populations
metapopulations
sub populations
What is the rescue effect?
when migration of individuals between subpopulations can inhibit extinction
Connections between habitat patches are known as _
corridors
what is biological control?
the use of predators/pathogens to control problematic species
