In K/r selection theory, what does the "K" signify?

In K/r selection theory, the "K" signifies the carrying capacity of an environment. Carrying capacity refers to the maximum population size that an ecosystem can sustainably support, considering the availability of resources such as food, habitat, and water. Organisms that are considered "K-selected" tend to thrive in environments where the population size is close to the carrying capacity. These organisms typically exhibit traits such as lower reproductive rates, longer gestation periods, and increased parental care, all of which can help ensure that offspring survive in a stable and competitive environment. This contrasts with "r-selected" species, which are adapted to take advantage of unpredictable environments and often reproduce quickly and in large numbers, leading to fluctuations in population size. Understanding the concept of carrying capacity is crucial in ecology and conservation, as it helps predict how populations might behave in response to changes in their environment.