abiotic factor

a non-living thing, such as water, temperature, and minerals, that affects an ecosystem

age–sex structure

the distribution of individuals in a species, categorized by both age and sex

biotic factor

a living thing that influences an ecosystem, such as prey, predators, and pathogens

carrying capacity

the maximum number of individuals of a population that a habitat can support


the life statistics of a population, such as births and deaths


limitations to population growth that vary with population density, such as food availability and disease


limitations to population growth that are not dependent on population density, such as weather and environmental catastrophes


the way in which individuals are arranged within the boundaries of a population

exponential growth

the rate of population growth in situations in which food and other resources are unlimited


the speed at which an individual of a species can produce offspring

introduced species

an organism from one ecosystem that is brought to live in a different ecosystem

invasive species

an organism that does not occur naturally in an ecosystem but thrives and often damages its new ecosystem

life history trait

the timing and characteristics of a significant event in the life cycle of a species

limiting factor

an environmental factor that restricts the growth of populations

logistic equation

a mathematical means of showing how the rate of increase in a population decreases as the population size increases

logistic growth model

a model that indicates how a population grows more slowly when a population reaches the carrying capacity of its environment


the rate of death in a population

native species

a species that is normally is found in a particular ecosystem


an interbreeding group of individuals of the same species

population density

the number of individuals of a population per unit of area

population ecology

the study of populations and how they interact with the environment

survivorship curve

a graphical representation of the numbers or proportions of individuals surviving at each age