Some people think that plant preservation pertains to drying the plant or lacquering it so that it does not wilt. This is not the true meaning of plant preservation. Take a rare orchid for example; by drying it how are you preserving it so that future generations may enjoy the sight of it? Quite simply, you're not. True rare plant preservation is decidedly more time-consuming.
Assisted migration is the practice in which the conditions in which a rare plant thrives are first identified. These include humidity, soil acidity, nutrient content, average rainfall, average temperatures, sunlight levels and other complementing plants. Once all these factors are found, other regions of the world are examined until one is found that matches the exact needs of the specific plant. The plant is then moved to this new region in the hopes that it will be more protected from land development and encroaching man so that it may flourish.
Reintroduction is a process similar to assisted migration. Plants are moved to new locations where they can grow and reproduce completely uninhibited. The difference is that the intention is to return these plants back to their original home once their numbers have improved. A variation of this method involves growing and propagating rare plant species under controlled conditions in greenhouses to plant the mature species back into their habitats.
On-site preservation is a method of preservation where legal action is taken to prohibit the trespass of man on the plant's natural habitat as well as to make land development in that area illegal. Off-site preservation is a method in which seeds and cuttings of rare plants are taken. They are placed in seed banks for long-term storage or are grown in greenhouses and botanical gardens. This differs from reintroduction in that off-site preservation does not intend to return the species back into the wild.