How is carrying capacity defined?

Carrying capacity is specifically defined as the largest population size that the environment can sustainably support without environmental degradation. This concept is crucial in ecology because it considers the limitations of resources such as food, water, and habitat space. When a population exceeds its carrying capacity, the environment can become stressed, leading to a decline in health, reproduction, and overall population numbers until they stabilize at a sustainable level. This dynamic helps to explain population fluctuations and the importance of resource management within ecosystems.

In contrast, the other options focus on different ecological concepts. The minimum number of individuals required for survival relates to a population's viability rather than its capacity to sustain a larger group. The total number of species in a region addresses biodiversity rather than population dynamics. The amount of resources available pertains to resource availability but does not directly encapsulate the concept of how many individuals the environment can support as a whole.