Population Ecology Lecture Notes

Practice vocabulary flashcards covering population parameters, growth curves, sampling methods, and community interactions.

Natality

The birth rate within a population, which increases population size.

Mortality

The death rate within a population, which decreases population size.

Immigration

The movement of organisms into an area.

Emigration

The movement of organisms out of an area.

Migration

The periodic movement of organisms into and out of a population.

Closed population

A population that experiences no immigration or emigration, where population size is affected only by natality and mortality.

Carrying capacity

The maximum number of individuals of a population that the environment can support.

Limiting factors

Resources in an environment that are in short supply.

Environmental resistance

The resistance the environment offers against any further growth in a population due to limiting factors.

Logistic (S-shaped) growth form

A population growth pattern consisting of a lag phase (needing acclimation), an accelerating/log growth phase (with plenty of resources), a decelerating growth phase (meeting environmental resistance), and an equilibrium phase where carrying capacity is reached and the birth rate equals the death rate.

Geometric (J-shaped) growth form

A population growth pattern characterized by an accelerating log growth phase due to the availability of water, food, and space, not remaining in the same area constantly.

Mark-recapture method

An indirect calculation method used to estimate population size using the formula $P = \frac{F \times S}{M}$, where $F$ is the first sample, $S$ is the second sample, and $M$ is the number of marked individuals in the second sample.

Quadrat method

An indirect sampling method used for stationary or slow-moving organisms that stay in fixed positions, calculated using $P = \text{avg} \times \text{habitat size}$ from several randomly chosen samples of the same size.

Census

A direct method of determining population size through physical counting by direct observation.

Aerial photography

A direct method used to observe and count large organisms to determine population size.

Population Ecology

The study of populations and how factors may affect the size and composition of these populations.

Species

Organisms with similar characteristics that are able to interbreed and produce fertile offspring.

Population

A group of organisms of the same species living in a particular habitat.

Community

A group of different populations living together in the same habitat.

Competition

An interaction where organisms compete for limited resources (such as light, space, water, minerals, food, shelter, and mates) so they can survive.

Intraspecific competition

Competition occurring between organisms of the same species.

Interspecific competition

Competition occurring between organisms of different species.

Competitive exclusion

A competitive interaction in which one of two competing species is much more successful than the other, resulting in one species surviving while the other dies out.

Resource partitioning

An interaction in which different species coexist in the same habitat because they use resources slightly differently, such as feeding at different levels.

Symbiosis

A relationship between two species of organisms that live in close contact with each other for part or all of their lifetime.

Mutualism

A symbiotic interaction where both species benefit from the relationship.

Commensalism

A symbiotic relationship where one organism benefits while the other is neither harmed nor benefited.

Parasitism

A symbiotic relationship where one organism (the parasite) benefits and the other organism (the host) is harmed.