The point at which the per capita growth rate of a population decreases is known as the carrying capacity. This concept refers to the maximum population size that an environment can sustain indefinitely without being degraded. Once a population exceeds this capacity, resources become limited, leading to increased competition and ultimately a decline in the growth rate. Factors contributing to this dynamic can include food availability, habitat space, and various environmental pressures. Understanding carrying capacity is crucial for effective population management and conservation efforts.