In a logistic model, the carrying capacity L is the maximum sustainable population.

In a logistic model, the carrying capacity L is the maximum sustainable population.

• A. The initial population
• B. The maximum sustainable population
• C. The current population
• D. The carrying capacity has no biological meaning

Answer: (B)

Carrying capacity is the maximum population the environment can sustain indefinitely given limited resources. In the logistic model, the parameter L is that carrying capacity: it’s the equilibrium population where growth stops, because dP/dt = 0 when P = L. If the population is below L, growth is positive and pushes P upward toward L; if the population is above L, growth is negative and pushes P downward toward L. The initial or current population are just actual values at a time, not the ceiling itself. Carrying capacity has real biological meaning, though it can change with resources and conditions. So the maximum sustainable population is the carrying capacity.

Carrying capacity is the maximum population the environment can sustain indefinitely given limited resources. In the logistic model, the parameter L is that carrying capacity: it’s the equilibrium population where growth stops, because dP/dt = 0 when P = L. If the population is below L, growth is positive and pushes P upward toward L; if the population is above L, growth is negative and pushes P downward toward L. The initial or current population are just actual values at a time, not the ceiling itself. Carrying capacity has real biological meaning, though it can change with resources and conditions. So the maximum sustainable population is the carrying capacity.