AP Environmental Science Unit 3

death rate equation

(number of deaths / total population) * 1,000

Birth rate equation

(number of live births / total population) * 1,000

Natural Rate of Increase Equation

(crude birth rate - crude death rate) / 10

environmental resistance factors

limits to available resources and space that constrain population growth

reproductive potential

the relative capacity of a species to reproduce under optimum, or nearly perfect, conditions

Survivorship

how different species exhibit unique evolutionary adaptations to access vital resources in order to grow, mature, and survive

Urbanization

the movement of large parts of a population from rural to urban areas

demographic transition

a theory of population dynamics; according to the theory, when the economy of a country or region becomes industrialized, or manufactures goods, its birth and death rates decrease

arable land

land that can be used to grow crops

Migration

the seasonal movement of animals due to changes in weather or resource availability

natural rate of increase (NRI)

a measure of how quickly a population size is changing

natality

the rate at which a species produces offspring over time

Population

A group of individuals that belong to the same species and live in the same area

Affluence

wealth, more resources used per person

Age Structure Diagram

a visual representation of the number of individuals within specific age groups for a country, typically expressed for males and females

Biotic Potential

The maximum rate at which a population could increase under ideal conditions

Carrying Capacity

Largest number of individuals of a population that a environment can support

Crude Birth Rate

The total number of live births in a year for every 1,000 people alive in the society.

Crude Death Rate

The total number of deaths in a year for every 1,000 people alive in the society.

Clumping

the most common dispersion pattern for populations, individuals flock together

Cohort

A population group unified by a specific common characteristic, such as age, and subsequently treated as a statistical unit.

Corridor

strips of natural habitat that connect populations

Community

All the different populations that live together in an area

Demographic Transition Model

a model of how the size of a population changes as a country develops its economy

Demography

The scientific study of population characteristics.

Density Dependent Factors

factor that limits a population more as population density increases

Density Independent Factors

limiting factor that affects all populations in similar ways, regardless of population size

Dieback

A sudden population decline; also called a population crash.

Exponential Growth Model

growth model that estimates a population's future size after a period of time based on the intrinsic growth rate and the number of reproducing individuals currently in the population

Doubling Time

The number of years needed to double a population, assuming a constant rate of natural increase.

Family Planning

the practice of regulating the number or spacing of offspring through the use of birth control

Fecundity

fertility

Generalist Species

Species with a broad ecological niche. They can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions. Examples are flies, cockroaches, mice, rats, and human beings. Compare specialist species.

Gross Domestic Product

The sum total of the value of all the goods and services produced in a nation

Immigration

Movement of individuals into a population

Emigration

movement of individuals out of a population

Inbreeding Depression

genetically similar parents mate and produce inferior offspring

Industrialization

the development of industries in a country or region on a wide scale.

Infant Mortality

the number of deaths of children under 1 year of age per 1,000 live births

Child Mortality

the number of deaths of children under age 5 per 1,000 live births

Intrinsic Growth Rate

under ideal conditions, with unlimited resources, the maximum potential for growth

J-shaped Curve

the curve of the exponential growth model when graphed

r-selected species

a species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs

k-selected species

a species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity

Specialist Species

Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.

Life Expectancy

The average number of years an individual can be expected to live, given current social, economic, and medical conditions. Life expectancy at birth is the average number of years a newborn infant can expect to live.

Limiting Resource

a resource that a population cannot live without and that occurs in quantities lower than the population would require to increase in size

Logistic Growth Model

a mathematical description of idealized population growth that is restricted by limiting factors

Malthus

said human population cannot continue to increase exponentially; consequences will be war, famine & disease

Malthusian Theory

Starvation is the inevitable result of population growth, because the population increases at a geometric rate while food supply can only increase arithmetically

Metapopulation

A group of spatially separated populations of one species that interact through immigration and emigration.

Mortality

death rate

Net Migration Rate

the difference between immigration and emigration in a given year per 1,000 people in a country

Overshoot

when a population becomes larger than the environment's carrying capacity

Parental Care

Any action by which an animal expends energy or assumes risks to benefit its offspring (e.g., nest-building, feeding of young, defense).

Population Density

Number of individuals per unit area

Population Distribution

a description of how individuals are distributed with respect to one another

Population Growth Model

Mathematical equation that can be used to predict population size at any moment in time

Population Growth Rates

explains how fast a given population grows

Population Momentum

The propensity for a growing population to continue growing even through fertility is declining because of their young age distribution

Population Pyramid

A bar graph representing the distribution of population by age and sex.

Population Size

total number of individuals in a population

Post-industrialization

the shift from an industrial economy dominated by manufacturing jobs to an economy dominated by service-oriented information-intensive occupations.

Pre-industrialization

The Stage of a nation before the phase of becoming industrialized, or large scale manufacturing/economic activity, where birth and death rates are high and people live in rather poor conditions

Random Dispersion

Random spacing of individuals of the same species within an area.

Replacement Level Fertility

The fertility rate necessary for a population to replace itself

Rule of 70

A method for determining the number of years it will take for some measure to double, given its annual percentage increase. Example: To determine the number of years it will take for the price level to double, divide 70 by the annual rate of inflation.

S-shaped Curve

the shape of the curve when a population is graphed over time using the logistic growth model

Sex Ratio

The number of males per 100 females in the population.

Survivorship Curve Type I

low death rates during early and middle life, then an increase among older age groups

Survivorship Curve Type II

the death rate is constant over the organism's life span

Survivorship Curve Type III

high death rates for the young, then a slower death rate for survivors

Survivorship Curve

Graph showing the number of survivors in different age groups for a particular species.

Theory of Demographic Transition

the theory that as a country moves from a subsistence economy to industrialization and increased affluence it undergoes a predictable shift in population growth

Total Fertility Rate

The average number of children born to a woman during her childbearing years.

Uniform Dispersion

The pattern in which individuals are equally spaced throughout a habitat.

Lag phase

period of growth in a variable that is notably slow