population

ecology

distribution

clumped, even, random

density

number of individuals per unit area or volume

pre reproductive

0-14

reproductive

15-44

post reproductive

45+

sex ratio

rations of males and females

immigration and births

increase population size

emmigration and deaths

decrease population size

exponential model of population growth

j shaped or hockey stick curve

logistic model of population growth

s curve

survivorship

the probability of newborn individuals

type 1

death comes near end of life span (late loss)

type 2

death rate fairly uniform throughout life span (constant loss)

type 3

high death rates for very young then decreases for adults (early loss/bloom and burst population)

TFR

total fertility rate

demographic transition

4 stages

stage 1

pre industrial - high birth ad death rates

stage 2

transition phase -

stage 3

industrial - birth and death rates decline - population stable like the US

stage 4

post industrial - birth rates continue to decline, death rates overtake birth rates, population age and decline

life expectancy

the average number of years that an infant born in a particular year in a particular year in a particular country can be expected to live, given the current average life span and death rate in that country