Seedlings, shoots and advances /runners are saplings. To reproduce, a tree produces an abundance of seedlings. Most of these do not survive. For instance, they are in a place where they are unwanted, are out-competed or there are too many of one species in one place. They are often cut away, or uprooted and thrown into the shredder. We harvest these seedlings to plant them out somewhere where they are allowed to become full-fledged trees.