NRES 348 — Lec 3: Community & Populations

What is a population?

A group of individuals of the same species living in the same place at the same time.

Why is population ecology important?

It helps us understand population changes, extinction risk, harvesting, environmental effects, & interactions between populations.

What is exponential growth?

Rapid population growth under ideal conditions with unlimited food, no predators or disease, & unlimited space.

What is carrying capacity (K)?

The number of individuals that the resources of a habitat can sustain.

What is logistic growth?

S-shaped population growth that slows as the population approaches carrying capacity.

What is population dynamics?

The study of changes in population size & composition & the factors that influence those changes.

What 4 factors change population size?

Births, deaths, immigration, & emigration.

What is the difference between density-dependent & density-independent factors?

• Density-dependent factors are related to population density

• Density-independent factors are not.

What is a community?

An interacting group of living organisms in the same area.

What is the difference between intraspecific & interspecific competition?

• Intraspecific = competition within the same species.

• Interspecific = competition between different species.