Population Growth & Regulation Vocabulary

Demography

The study of populations

Growth Rate

In a population, the number of new individuals that are produced per unit of time minus the number of individuals that die

Intrinsic Growth Rate ( r )

The highest possible per capita growth rate for a population

Exponential Growth Model

A model of population growth in which the population increases continuously at an exponential rate

J-Shaped Curve

The shape of exponential growth when graphed

Geometric Growth Model

A model of population growth that compares population sizes at regular time intervals

Doubling Time

The time required for a population to double in size

Density Independent

Factors that limit population size regardless of the population’s density

Population Dependent

Factors that affect population size in relation to the population’s density

Negative Density Dependence

When the rate of population growth decreases as population density increases

Self-Thinning Curve

A graphical relationship that shows how decreases in population density over time lead to increases in the size of each individual in the population

Carrying Capacity (K)

The maximum population size that can be supported by the environment

Logistic Growth Model

A growth model that describes slowing growth of populations at high densities

S-Shaped Curve

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

Inflection Point

The point on a sigmoidal growth curve at which the population has its highest growth rate

Life Tables

Tables that contain class-specific survival and fecundity data

Stable Age Distribution

When the age structure of a population does not change over time

Survivorship

The probability of surviving from birth to any later age class

Net Reproductive Rate (R0)

The total number of female offspring that we expect an average female to produce over the course of her life

Generation Time (T)

The average time between the birth of an individual and the birth of its offspring

Cohort Life Table

A life table that follows a group of individuals born at the same time from birth to the death of the last individual

Static Life Table

A life table that quantifies the survival and fecundity of all individuals in a population in a population during a single time interval