Chapter 3 Flashcards
What strategy do humans use?
Humans use K strategy
Characteristics of K strategy
Long lifespan, late sexual maturity, few young, high parental care
4000 BCE to 1347
Stable population, limiting factors are significant, S shaped growth curve
1347 to 1350
Bubonic plague (black death)
1700
industrial revolution, advanced agriculture methods, domestication of animals, advanced medicines, led to exponential growth
Today
J shaped exponential growth curve
Exponential population growth is a large concern on our planet
Two ways to examine population growth
- Percent population growth
- Doubling time
Percent population growth
Rapid population growth
Why? Birth rate remains the same but death rate has fallen
Doubling Time
The time it takes for a population to double in number. This has greatly decreased from 200 yrs, 80 yrs to 46 yrs
Death rate is ___ in developed countries
Slower
Death rate is ____ in developing countries
Faster
Demographic Transition
A. theory that describes the pattern if birth rates, death rates & growth rates of populations overtime
Stage 1: (pre transitions) early human societies
- high BR (no knowledge of birth control)
- high DR (no modern medicine)
- zero population growth
Stage 2: (early transition/demographic trap)
- high BR (no knowledge of birth control)
- low DR (more medicine, better food production)
- rapid population growth
- many under developing countries
- being trapped in stage 2 is called the demographic trap
Stage 3: (late transition/demographic transition)
- decreased BR (knowledge of birth control, better living standards)
- death rate decreases
- population growth slows
- most developing countries
Stage 4: (post transition)
- low BR
- low DR
- population growth slows to zero
- most developed counties
Stage 5: (constricting population growth)
- BR falls below DR
- population growth is shrinking
Population Pyramids
a bar graph used by demographers which shows the age distribution in a population
- can be used to predict the populations growth potential
- % of males in a different age group (left)
- % of females in different age group (right)
- age on y axis
Age Distribution=
% of people in different age groups
Expansive Population
- triangular shape
- rapid population growth, why?
- many young people of reproductive age
- fewer old people (not reproducing)
- decreased average lifespan (standard of living low)
- fertility rate: 4.7 children per female
Stable Population
- rectangular shape
- zero population growth, why?
- fewer young people of reproductive age
- increased average lifespan (high standard of living)
- fertility rate: 1.7 children per family
Constrictive Population
- inverted triangular shape
- negative population growth, why?
- fewer young people of reproductive age
- large number of people past reproductive age
Ecological Footprint
The amount of land that is required to support each person for their needs (food, water, transportation, housing & waste management in a country)
6 major categories to human demands…
a) crop land (how much land we require to grow food)
b) grazing land ( how many animals do we eat)
c) fishing ground
d) forest land (building & paper)
e) carbon absorption (transportation - cars, trains)
f) building area
Biocapacity
The earths carrying capacity for the human population
Biocapacity in developed countries
Large carrying capacity (biocapacity) ecological overshoot we place many demands on environment
Biocapacity in developing countries…
have a smaller carrying capacity (biocapacity)
Impact of large ecological footprint on Earth
1) Declining Bio diversity
2) Threats to sustainability
Sustainability
The quality of causing little or no damage to the environment over a continued period of time
ex: recycling habits
