Which population size has the highest growth rate among those above carrying capacity?

• A. 1500
• B. 1520
• C. 1530
• D. 1510

Answer: (D)

When a population exceeds carrying capacity, resources become limiting and the population tends to decline toward the carrying capacity. In this situation the growth rate dN/dt is negative, and the further above carrying capacity a population is, the larger (in magnitude) that negative rate becomes.

Among sizes above carrying capacity, the one closest to carrying capacity declines the least quickly and thus has the highest growth rate (the least negative dN/dt). Here, if carrying capacity is 1500, then 1510 is the smallest population above it, so it experiences the smallest decline compared with 1520 and 1530. The value at 1500 is at carrying capacity, not above, so it isn’t in this group.

So 1510 has the highest growth rate among those above carrying capacity.