In population ecology, what is population density?

• A. The maximum population size an environment can sustain indefinitely (carrying capacity)
• B. The rate at which individuals are added to a population through births and immigration
• C. The total number of individuals of a species in a habitat regardless of area or volume
• D. The number of individuals of a species per unit area or volume at a given time

Answer: (D)

Verified step by step guidance

1. Understand that population density refers to how many individuals of a species are found in a specific area or volume at a particular time.
2. Recognize that population density is different from total population size, which counts all individuals without considering the space they occupy.
3. Note that population density is expressed as the number of individuals divided by the unit area (e.g., per square kilometer) or unit volume (e.g., per cubic meter).
4. Use the formula for population density: \(\text{Population Density} = \frac{\text{Number of Individuals}}{\text{Area or Volume}}\).
5. Remember that population density helps ecologists understand how crowded a population is, which can affect resource availability and interactions among individuals.