A plantation is a large piece of land (or water) usually in a tropical or semitropical area where one crop is specifically planted for widespread commercial sale and usually tended by resident laborers. The crops grown include fast-growing trees (often conifers), cotton, coffee, tea, cocoa, sugar cane, sisal, oil seeds (e.g. oil palms), rubber trees, and various fruits. Protectionist policies and natural comparative advantage have sometimes contributed to determining where plantations were located.