Population Ecology: Logistic Growth, Overshoot, and Life Histories

Vocabulary flashcards covering key concepts from the lecture notes on logistic growth, carrying capacity, overshoot, life history traits, and reproductive strategies (semelparity vs. iteroparity), plus r- and K-selection and related trade-offs.

Carrying capacity (K)

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

Logistic growth model

A population growth model in which per capita growth rate decreases as N approaches K; described by dN/dt = rN(1 − N/K).

Overshoot

A situation where a population temporarily exceeds carrying capacity (K) due to delays in resource effects or reproduction, before declining.

Intrinsic rate of increase (r)

The maximum potential growth rate of a population under ideal conditions (per capita rate of increase when resources are plentiful).

Life history traits

Traits that determine the schedule of reproduction and survival, including age at first reproduction, frequency of reproduction, and number of offspring per reproductive episode.

Semelparity

One-shot or big-bang reproduction—reproducing only once in a lifetime, often followed by death (examples: coho salmon, agave).

Iteroparity

Repeated reproduction across multiple seasons or years; organisms reproduce more than once (examples: loggerhead turtle, oaks).

Age at first reproduction

The age at which an organism begins reproducing; a key life-history trait.

r-selection

Selection for traits that maximize population growth rate in low-density or disturbed environments; produces many small offspring with little parental care (e.g., weeds).

K-selection

Selection for traits that maximize success near carrying capacity; produces fewer offspring with greater parental investment (e.g., mature trees).

Trade-offs

Allocation of limited resources to one function (like reproduction) that reduces resources available for another (like survival), shaping life-history strategies.

Parental care

Investment by parents in offspring survival; higher care can reduce the number of offspring or parental survival in some contexts (e.g., kestrels).

Offspring number (fecundity)

The number of offspring produced; variation in offspring number influences life-history strategies and survival.

One-shot reproduction

Semelparity—the single reproductive event before death (examples: coho salmon, century plant).

Repeated reproduction

Iteroparity—the ability to reproduce multiple times across life; examples: loggerhead turtle, horses, oaks.