K-selected species are described as species selected by environments that are:

1. The two life-history strategies suit different environments. 2. Reproductive strategies alone do not account for limited resources and competition. 3. That leads to the classical concept of K-selected versus r-selected species. 4. K-selected species are species selected by stable, predictable environments. 5. Their name comes from the carrying capacity K that such environments impose. _Source: OpenStax Biology 2e (CC BY 4.0), Ch 45 'Population and Community Ecology', sections 45.1-45.4_