Population Ecology - Video Notes Flashcards

Vocabulary flashcards covering key terms and concepts from the population ecology lecture notes.

Biosphere

The global sum of all ecosystems; the zone of life on Earth.

Biomes

Large, distinct ecological communities characterized by similar climates and organisms.

Ecology

The study of how organisms interact with each other and their environment.

Ecosystem

A system consisting of living organisms and their physical environment, with energy flow and nutrient cycling.

Energy flux and cycling of nutrients

The movement of energy through an ecosystem and the circulation of nutrients among organisms and their environment.

Community

Interactions among populations of different species living in the same area.

Population

A group of individuals of a single species occupying the same general area; the unit of population dynamics and evolution.

Organism

An individual living thing; its survival and reproduction are the units of natural selection.

Population ecology

The study of how and why the number of individuals in a population changes over time and with environmental factors.

Mark–recapture

A method to estimate population size by capturing, marking, releasing, and later recapturing individuals.

Sampling limitations

Limitations in estimating population size due to nonrandom distribution (clumped, random, uniform) and sampling method.

Clumped dispersion

Individuals aggregated in patches, often due to resource availability or social behavior.

Uniform dispersion

Evenly spaced distribution, often from territoriality or competition.

Random dispersion

No distinct pattern; occurrences are by chance rather than pattern.

Mark-release-recapture

The process of capturing, marking, releasing, and later recapturing to estimate population size.

Lincoln–Petersen estimator (N ≈ (s × n) / x)

A formula to estimate total population size: N = (s × n) divided by x, where s is initial marked sample, n is second sample, and x is marked individuals recaptured.

Assumptions of mark–recapture

No births/deaths or migrations occur, marked individuals mix with unmarked, marking doesn't affect catchability, marks are not lost, and enough time passes for mixing.

Birth rate (b)

Per-capita rate at which individuals give birth; part of growth rate calculations.

Death rate (d)

Per-capita rate at which individuals die; part of growth rate calculations.

Growth rate (r)

r = b − d; positive r indicates growth, negative r indicates decline.

Exponential growth

Unrestricted growth where population increases at a constant rate per capita, yielding a J-shaped curve.

Logistic growth

Growth that slows as carrying capacity is approached, producing an S-shaped curve.

Carrying capacity (K)

The maximum population size that the environment can sustain indefinitely given resources.

Density-dependent factors

Factors whose impact increases with population density (e.g., competition, disease, predation).

Density-independent factors

Factors that affect population size regardless of density (e.g., weather, disasters, habitat destruction).

Age structure

The distribution of individuals among age classes, used to predict future growth.

Survivorship curves (Type I/II/III)

Graphs showing the probability of surviving at each age; Type I: high juvenile survival, Type II: constant, Type III: high juvenile mortality.

Life history traits

Traits that influence growth, reproduction, and survival (e.g., age of first reproduction, fecundity).

Fecundity

Average number of female offspring produced by a female.

Age-specific fecundity

Fecundity measured for females in specific age classes.

Four demographic factors

Births, deaths, immigration, and emigration; these determine population size changes.

Age structure diagrams

Graphs (pyramids or rectangles) showing the age distribution and indicating potential growth or stability.

Predator–prey cycles

Boom-and-bust population dynamics arising from interactions between predators and their prey.

Asian Carp example

An invasive species showing rapid, exponential-like growth (r ≈ 1); high fecundity (up to ~1.9 million eggs per female) and multiple yearly spawning events.

Global carrying capacity for humans

The biosphere’s maximum sustainable human population; estimates project ~8.1–10.6 billion by 2050.

Human population growth pattern

Often described as exponential due to industrial and medical advances, rather than strictly logistic in early stages.

Age structure diagrams (expanding vs stable vs contracting)

Graphs that predict future growth: expanding (triangular), stable (rectangular), or contracting (inverted pyramid).