Question

What are three basic population growth curves? When might you see them in nature?

Short answer

The three basic population growth curves are the J-shaped curve (exponential growth), the S-shaped curve (logistic growth), and the oscillation or boom and bust curve. You might see them in nature in situations such as the rapid spread of rabbits in Australia (exponential), the growth of a deer population in a forest until food resources run low (logistic), and the sudden population crash after a locust plague consumes all available food (boom and bust).

Step-by-step solution

Identify the Three Basic Population Growth Curves

There are three typical forms of population growth curves: (1) J-shaped curve which represents exponential population growth, (2) S-shaped curve, also called Logistic population growth, and (3) oscillation, or boom and bust curve.

Explain the J-Shaped Curve (Exponential Growth)

In the J-shaped curve model, the population grows exponentially without any constraints, meaning the number of individuals increase rapidly over time - often seen in new environments with ideal conditions and resources.

Explain the S-Shaped Curve (Logistic Growth)

S-shaped curve or logistic population growth model describes the growth which has upper limits due to environmental factors. Starting slowly, the population increases rapidly at intermediate levels, and slows down as it approaches carrying capacity.

Explain the Oscillation or Boom and Bust Curve

Oscillation curves or boom and bust are characterized by rapid population increase followed by a sudden crash. This is often seen in species that over-consume their resources.

Provide an Example of Each in Nature

Exponential growth can often be seen in organisms introduced to new environments, such as the spread of rabbits in Australia. Logistic growth might be found in populations like deer in a forest, which can grow rapidly until food shortage takes effect. Oscillations or boom and bust patterns can be found in species such as plagues of locusts, which consume all available food leading to a sudden population crash.