6.2 Population Ecology

Flashcards about population ecology based on lecture notes.

What are the levels of ecology discussed in the lecture?

Population, community, and ecosystem ecology.

What is population demography?

Using mathematical tools to look at changes in populations over time; involves statistics, tables, and figures.

What notation is used to represent population size?

A capital N (italicized).

How is population density defined?

Population size taking into account the specific area or volume they exist in.

What are the three distribution patterns?

Uniform, random, and clumped.

What characterizes uniform distribution?

Evenly spaced organisms, often seen in territorial animals.

What characterizes random distribution?

Organisms spaced randomly, common in plants with wind-dispersed seeds.

What characterizes clumped distribution?

Organisms grouped together, often around resources or in herds.

What is a complete census?

Counting every individual within a given population.

What is the mark and recapture method used for?

Estimating population size, especially for mobile animals.

What are quadrats and what information do they provide?

Meter or half-meter squares used to quantify species in a specific area, providing data for population size and density.

What is the difference between distribution and geographic range?

Distribution refers to a local population while geographic range is pertinent to the entire species.

What is a home range?

The area where an organism is found during its lifetime.

What is a territory?

A smaller area that some animals defend, which is smaller than their home range.

What factors increase population size?

Birth rate and immigration.

What factors decrease population size?

Death rate and emigration.

What are life tables?

Tables that show the life expectancy and survival rates of individuals in a population at different ages, often divided by sex.

What are survivor shift curves?

Graphical representations of data from life tables.

What are the three general types of survivorship curves?

Type one, type two, and type three.

What characterizes a type one survivorship curve?

Low risk of juvenile death, high parental care, and few offspring (e.g., primates).

What characterizes a type two survivorship curve?

Equal risk of death throughout all life stages (e.g., birds).

What characterizes a type three survivorship curve?

High risk of mortality at a young age, many offspring, and little parental care (e.g., frogs).

What is exponential growth?

Population growth with unlimited resources, resulting in a steep, J-shaped curve.

What is logistic growth?

Population growth that initially grows rapidly but levels out as resources become limited, resulting in an S-shaped curve.

What is carrying capacity?

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

What are limiting factors?

Environmental conditions that keep a population at a certain size.

What are density independent factors?

Factors that affect population size regardless of population density (e.g., precipitation, floods, droughts).

What are density dependent factors?

Factors that affect population size based on population density (e.g., predation, infectious diseases, accumulation of waste).

What is interspecific competition?

Competition between different species for the same resources.

What is an energy budget?

How much energy is required for an organism to go through its life processes such as growth and reproduction.

What are life history patterns?

Patterns that take into account survivorship curves as well as trade offs that must be made in regards to energy use.

What is fecundity?

The number of offspring an organism can produce in its lifetime.

What are semelparous species?

Species that reproduce only once in their lifetime (e.g., salmon).

What are iteroparous species?

Species that reproduce multiple times throughout their lives (e.g., mammals).

What are opportunistic life history patterns?

Short lifespans, early reproduction, many offspring, and little parental care (Type III survivorship curve).

What are equilibrium life histories?

Longer lifespans, late sexual maturity, and extensive parental care (Type I survivorship curve).

What information can be gathered from looking at the shape of a population pyramid?

Whether a population is growing, stable, or decreasing.