Final answer:
In a logistic model, a population's growth rate is maximal at half of the carrying capacity, when the logistic 'S' curve is steepest. The growth rate then slows as resources become limited and the population size approaches its carrying capacity.
Step-by-step explanation:
When a population grows according to a logistic model, the growth rate is maximal at half of the carrying capacity. This is due to the fact that when resources are plentiful (e.g. at the start of the growth curve), the population grows exponentially. However, as resources become limited and the population size approaches its carrying capacity, the growth rate slows down and eventually stabilizes. The carrying capacity is defined as the maximum number of individuals that the environment can support.
The moment when the growth rate is largest can be visualized as the steepest part of an 'S' curve representing logistic growth. In a real-life scenario when the population grows logistically, this might be when a plant population reaches around 60 individuals in an environment with a carrying capacity of 120, or when a population of animals reaches 58 in an environment that can support 116.
Learn more about Logistic Population Growth