Humans select and accumulate varieties of plants, caring for, managing, and cultivating them. These interactions lead to four kinds of cultures, whose names originate in Latin: agriculture—the tending of fields; arboriculture—the tending of trees; horticulture—the tending of gardens; and silviculture—the tending of forests. In 1939, Oakes Ames pointed out that the genetic consequences of human selection and propagation are different in agriculture and horticulture; the same is true in arboriculture and silviculture. In horticulture, annual plants are treated as individuals, which allows more intensive selection with a larger response to selection, i.e., more variability through time. In agriculture, plants are treated as populations although individual plants are selected to create the next generation; selection is less intensive because of the numerous plants composing the next generation, and the response is slower. In arboriculture, individual trees are selected and tended; when planted in gardens and swiddens, there can be intensive selection, but generation times are longer, so overall variability is less than in horticulture. In silviculture, individual trees and other plants are also selected and tended but continue to receive gene flow from unselected trees/plants, which acts to reduce selection intensity and response. In agri-, arbori-, and horticulture, populations are often fully domesticated, i.e., with large changes in their domestication syndromes and dependence upon their humans and domesticated landscapes for survival. In silviculture, populations tend to be incipiently domesticated, with small changes in their domestication syndromes and full survival outside of fully domesticated landscapes.