unit 3 Flashcards
biosphere
where life is found
ecosystem
group of communities
community
group of population
population
group of organisms
k-selected species
reproduce late in life, small number of offspring with long life spans, lower population growth rate, high parental care
r-selected species
large populations of small-sized offspring, early reproductive age, high rate of population increase, low parental care
biotic potential
unrestricted pop growth allows for max pops; k = low biotic potential, r = high biotic potential
type 1 surviviorship
late loss (death due to old age), high survivorship, mammals
type 2 survivorship
environment causes death independent of age, birds/reptiles
type 3 survivorship
lowest survivorship in youth, early loss, most common
density dependent factors
environmental factor on population change, determined by density; ex. predator population, disease, competition
density independent factors
environmental factor affecting size of population but not influenced by changes in population density; ex. random weather events, resource shortages
carrying capacity
number of organisms that can be supported by an ecosystem without environmental degredation
population exceeds carrying capacity
overshoot occurs, resource depletion = dieback occurs from disease, famine, conflict
malthusian theory of carrying capacity
catastrophe occurs; above crisis = insufficient resources, below crisis = excess of resources
developed countries
high average per capita GDP, highly industrialized, slower pop. growth; ex. US, Japan, Australia, Canada
developing countries
low/middle income, low/moderate per capita GDP, fast growing, all other countries, most of Asia, Africa, Latin America
world pop. growth
has decreased, is now 0.88%
population growth will continue to occur until..
dieback occurs OR BR = DR and population growth rate reaches 0
growth can be affected by
density dependent (access to clean water, spread of disease) and independent (drought, famine) factors
replacement fertility level
of children a couple must bear to replace themselves, 2.1 in developed, 2.5 in developing
total fertility rates
estimated average number of children a woman will have during reproductive years, highest TFR in africa, developed = TFR below replacement rate
what factors affect TFR
importance of children in labor force, cost of raising and educating kids, availability of private/public pension, urbanization, education and employment for women, infant mortality rate, average age at which women start having kids, availability of contraception/family planning
crude birth rate
of live births/1000 people/year, have been decreasing
crude death rate
of deaths/1000/year, have been decreasing faster than CBR
factors affecting death rates
people started living longer - increased food supplies and distribution, better nutrition, improved public health, improved sanitation and hygiene, safer water supplies
demographic transition model
how economic development affects population overt time, 4 stages
preindustrial stage
hunter-gatherer, agriculture, harsh conditions, high birth and death rates, may experience slow growth, NO COUNTRIES IN STAGE 1
transitional stage
some industrialization, food production rises, health care improves, death rates drop, birth rates remain high
industrial stage
widespread industrialization, birth control, jobs and education available, kids are $$, birth rates decline, population growth slows
postindustrial stage
sustainable use of resources, 0 population growth or decline, 37 of countries today
problems associated with declining population
number of people paying for public pension program declines, number of people withdrawing from public pension rises, labor market shrinks = number of unfilled jobs increases, less people to care for elderly
role of family planning
responsible for half of total fertility rate drops in developing countries
population growth in the future
97% is expected to take place in developing countries, poverty = higher brith rates (less contraceptives, birth control, etc.)
economic rewards
$$ offered to those who use sterilization or contraceptives
economic penalties
china penalizes couples who have more than one or two kids with taxes, fees, etc. (one-child policy)
consequences of not controlling population growth
higher death rate due to declining health and environmental conditions, human footprints + increases resource use = degrades environment
how can you reduce population growth
increase economic roles for women, advance women’s rights, gov supports family planning, free contraceptives + ads/encouragement for contraceptives
2 factor population change (# of people)
B-D
4 factor population change (# of people)
(B+I) - (D+E)
calculate rate of increase/growth rate
% = population change/original population x 100
calculate rate of increase/growth rate WITH crudes
% = CBR-CDR/10
doubling time
70/rate of increase
