The document discusses the concept of carrying capacity, which is defined as the maximum population size that can be sustained by the environment indefinitely. It notes that population growth is influenced by birth rates, immigration, death rates, and emigration. When the population exceeds the carrying capacity, it degrades the environment and reduces future carrying capacity. Factors like competition for resources, predation, disease, and weather affect the carrying capacity. Population growth follows a logistic curve as it slows down upon reaching the carrying capacity. Carrying capacity is relevant for urban planning and tourism management.