Population Ecology

This set of flashcards covers key vocabulary and concepts from the Population Ecology lecture, focusing on definitions, contrasts, and specific examples related to population dynamics, reproductive strategies, and demography.

What is ecology?

The study of the interactions of organisms with the biotic and abiotic components of their environment.

Population ecology

The study of the structure, size, and stability of species populations.

Population

A group of individuals of a single species that live in a particular area and interact with one another.

Conspecific interactions

Interactions between members of the same species.

Heterospecific interactions

Interactions between members of different species.

Population size

The total number of individuals in a population.

Population density

The number of individuals within a specific area.

High density

Greater stability, ease of finding mates, and reduced genetic drift.

Low density

Reduced stability, difficulty finding mates, and increased genetic drift.

Species dispersion patterns

The spatial relationship between members of a population within a habitat.

Uniform dispersion

An even spacing between members of a population.

Random dispersion

No clear pattern in spacing between members of a population.

Clumped dispersion

Structured spacing between members of a population in dense aggregations.

Demography

The study of population changes over time.

Birth rate

The number of births per size unit of a population (usually per 1,000).

Death rate

The number of deaths per size unit of a population (usually per 1,000).

Life expectancy

The average age at death of population members.

Energy budget

The balance of energy intake with expenditure for metabolism, development, reproduction, etc.

Life history

A series of events over a species' lifetime.

Fecundity

Potential reproductive capacity of an individual.

Reproductive frequency

The number of times a species reproduces, affecting fecundity and survival.

Semelparity

When a species reproduces only once during its lifetime and then dies.

Example of Semelparity

Mayflies, which are short-lived.

Example of Semelparity

Chinook salmon, which are long-lived.

Iteroparity

When a species reproduces repeatedly during its lifetime.

Seasonal estrus cycles

Mating occurs within a specific time of year coinciding with reproductive capacity.

Menstrual cycles

Mating occurs at any time, though reproductive capacity may be confined to a few days a month.

Trade-off with parental care

Fecundity is inversely related to the level of parental care.

Population changes

Affected by population size, birth rate, death rate, and population density.

Higher population density

Leads to more chances to find mates and higher birth rate.

Increased competition

Higher population density can lead to increased competition and disease transmission.

Energy expenditure

Species use their energy budget differently during reproductive events.

Impact of population density on birth rate

Higher density can lead to higher birth rates.

Impact of population density on death rate

Higher density can lead to higher death rates.

Reproductive strategies

Energy allocation strategies that affect fecundity and survival.