38 terms

Tragedy of the Commons and Population Growth


Terms in this set (...)

Exponential Growth
Doubling in even increments
Clumped Dispersion Patterns
The organisms live together and eventually form packs
Logistic Growth
Pattern in which exponential population growth occurs when the population is small and population growth decreases steadily with time as the population approaches the carrying capacity
Random Dispersion Patterns
There are random organisms placed randomly in a given area (spreading of seeds)
Linear Growth
1:1 ratio; slow and steady growth
Uniform Dispersion Patterns
Even amount of space between organisms (plants in a desert)
Static Growth
As one organism dies, another one is born having no growth
Limiting Factors
Factors that limit the growth, abundance, or distribution of the population of a species in an ecosystem
Replacement Level Fertility Rate (RLF)
Average number of a children a couple must bear to replace themselves. The average for a country or the world usually is slightly higher than two children per couple mostly because some children die before reaching their reproductive years.
Population Density formula
Number of organisms in a particular population found in a specified area or volume.
Carrying Capacity (K)
The maximum number of individuals in a population that a habitat can support indefinitely
Total Fertility Rate (TFR)
Estimate of the average number of children who will be born alive to a woman during her lifetime if she passes through all her childbearing years conforming to age-specific fertility rates of a given tear. More simply, it is an estimate of the average number of children that women in a given population will have during their childbearing years.
Formula for Population Change
(births + immigration) - (deaths - emigration)/ total population
Less Developed Country (LDC)
Country that has low to moderate industrialization and low to moderate per capita GDP. Most are located in Africa, Asia and Latin America
More Developed Country (MDC)
Country that is highly and has a high per capita GDP
Rule of 70
Doubling time (in years) = 70/ (percentage growth rate)
Density-Dependent Limiting Factors
Biotic Potential
Maximum rate at which the population of a given species can increase when there are no limits on its rate of growth
Ecological Footprint
Amount of biologically productive land and water needed to supply a population with renewable resources it uses to absorb or dispose of the wastes from such resource use. It is a measure of the average environmental impact of populations in different countries and areas.
Density-Independent Factor
Weather and climate; exert their influences on population size regardless of the population's density
Age Structure Pyramid
Percentage of the population (or number of people of each sex) at each age level in a population
Birth (natality) Rate
Annual number of live births per 1,000 people in the population of a geographic area at the midpoint of a given year
Death (mortality) Rate
Annual number of deaths per 1,000 people in the population of a geographic area at the midpoint of a given year
Demographic Transition
Hypothesis that countries, as they become industrialized, have declines in death rates followed by declines in birth rates
Movement of people out of a specific geographic area
Migration of people into a country or area to take up permanent residence
Total Migration Rate
The difference between the number of immigrants and the number of emigrants throughout the year
IPAT Model
Proposed by Ehrlich and Holdren; way to calculate the impact of the humans on the environment; I = P(population)A(Affluence), and T(technology)
R-Related Species
Emphasize high growth rates, typically exploit less-crowded ecological niches and produce many offspring, each of which has a relatively low probability of surviving adulthood
K-Related Species
Possess relatively stable populations and tend to produce relatively low numbers of offspring, however, individual offspring tend to be quite large in comparison with this species
Reproductive Age
Between menarche and menopause, roughly from ages 12-49. The term is imprecise, since some women can become pregnant and bear children at younger or older years. In men, those years between the onset of puberty and loss of fertility
Pre-Reproductive Stage
Post-Reproduction Stage
Industrial Stage
Pre-Industrial Stage
Post-Industrial Stage
Transitional Stage
Ability of earth's various systems, including human cultural systems and economies to survive and adapt to changing environmental conditions indefinitely