What factor primarily affects the carrying capacity of an ecosystem?

The carrying capacity of an ecosystem is fundamentally determined by the availability of resources such as food, water, and shelter. This concept reflects the maximum population size of a species that an environment can sustain indefinitely without degrading the environment. When resources are abundant, populations can thrive and increase; conversely, if resources are limited, the population will decline or stabilize at a lower level.

While the variety of species present can influence interactions within an ecosystem, it does not fundamentally determine the maximum population that can be supported. Similarly, the reproductive rate of individual species plays a role in population dynamics but is not the primary factor in defining how many organisms the ecosystem can support long-term. The geographical area of the ecosystem may affect resource distribution and availability, but it is ultimately the availability of essential resources that directly impacts carrying capacity. Thus, the consistent availability of food, water, and shelter is the pivotal factor that shapes the carrying capacity of an ecosystem.