Population and Human Dynamics Flashcards
Module 3
all members of a single species living in a specific area at the same time
population
number of individuals (individuals)
population size
number of individuals living in a given area (individuals/km2)
population density
number of live births added annually per 1000 individuals
birthrate (natality)
number of deaths added annually per 1000 individuals
deathrate (mortality)
movement of individuals into a population
immigration
movement of individuals out of a population
emigration
number of males with respect to number of females
sex ratio
3 age distribution
pre-reproductive juveniles
reproductive adults
post-reproductive adults
2 types of growth
exponential and logistic
an increase in individuals per unit of time
“growth with no limit”
exponential growth rate
the maximum population size of a biological species that can be sustained by that specific environment
carrying capacity
changes in growth over time
(growth slows when approaching carrying capacity)
logistic growth rate
factors that prevent the further increase of the population
determines an ecosystem’s carrying capacity
limiting factors
the totality of all limiting factors
environmental resistance
4 factors affecting growth
external factors
internal factors
density-dependent factors
density-independent factors
factor affecting growth-
habitat quality, food availability, interactions
external factors
factor affecting growth-
slow growth and maturity, body size, metabolism, hormonal status, etc.
internal factors
factor affecting growth-
effect intensifies with increase in population size
density-dependent factors
factor affecting growth-
population affected no matter what size (often abiotic)
density-independent factors
usually small, high reproductive rate, high mortality, ignored offspring
depend on high rate of reproduction and growth
r-strategists
tend to be large, live long lives/mature slowly, care for offspring, low reproductive rate, low mortality
adapted for slower growth conditions near carrying capacity
K-strategists
survivorship- most individuals die late in life
Type 1
survivorship- individuals die at a uniform rate
type 2
survivorship- most individuals die at a young age
type 3
