By far, the majority of forest and conservation tree seedlings are grown from seed, and most of this seed is collected from plants in the wild. Because seedlings must be genetically-adapted to the environment on the outplanting site, foresters insist on "source-identified" seed. Seed collected from a specific location in a particular year is called a "seed lot", and is identified by a numerical seed code. When the seed is sown, this seed code will identify the seedlings until they are shipped back to the same geographical location for outplanting.
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