Population Dynamics and Ecological Interactions

Flashcards covering population growth, distribution patterns, and ecological interactions.

Population Density

Number of individuals in a given volume or area. Formula: Dp = N/A or Dp = N/V

Uniform Distribution

A distribution pattern where the distance between neighboring individuals is maximized due to competition for resources; evenly spaced.

Random Distribution

A distribution pattern with unpredictable spacing; the least common distribution in nature.

Clumped Distribution

The most common type of dispersion found in nature, where the distance between neighboring individuals is minimized, often around resources.

∆N = [b + i] - [d + e]

change in population size =(births + immigration)-( deaths + emigration)

Growth Rate (gr)

The change in the number of individuals in a population over a specific time frame. Formula: gr= ∆ N / ∆ t

Per Capita Growth Rate (cgr)

The change of population size is a rate per individual. It takes into account the original population size; used to compare populations of different sizes. Formula: cgr= ∆ N / N

Biotic Potential (r)

Highest possible per capita growth rate for a population given unlimited resources & ideal living conditions.

Carrying Capacity (K)

The maximum population size that the environment can sustain.

Density-Dependent Factors (BIOTIC)

Factors that arise from population density (limited resources, food, space).

Density-Independent Factors (ABIOTIC)

Factors that affect members of a population regardless of size/density (flood, fires, temperature).

K-Selected Species

Species whose population sizes fluctuate at or near their carrying capacity (K); few offspring, long maturation.

R-Selected Species

Species that reproduce close to their biotic potential (maximum reproductive capacity); many offspring, short lifespan.

Intraspecific Competition

Competition for limited resources among members of the same species.

Interspecific Competition

Competition between members of different species in the same community.

Batesian Mimicry

A harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator.

Mullerian mimicry

A natural phenomenon in which two or more poisonous species mimic each other's warning signals

Mutualism

When both partners benefit from the relationship.

Commensalism

One partner benefits and the other neither benefits nor is harmed.

Parasitism

One partner benefits at the expense of the host.

Succession

Slow, orderly, progressive replacement of one community by another during the development of vegetation in an area.

Primary Succession

Succession on barren rock with no soil present, starting with pioneer species

Secondary Succession

Succession after an ecological disturbance where soil is still present.

Sustainability

Living in a way that meets our needs without compromising the health/resources of future generations.

Age Pyramids

A graphical illustration that examines a population's age structure and proportion of males and females- used to assess a population's potential for growth.