Natural Regeneration

There are several ways in which trees reproduce themselves, which is called natural regeneration.  They drop seeds - a few of which germinate into seedlings. If hardwoods are cut down when they are relatively young, their stumps can sprout. Some hardwoods, including aspen, sprout from their roots after they are cut down. Some trees sprout from a buried branch, but those species are not here.

The heavier nuts of oak, walnut, butternut, and hickory fall directly to the ground near the parent tree; but they may be moved (this is called dispersal) by birds, mammals, and gravity. In fact, when blue jays in Germany were tracked, it was discovered that each bird moved about 4500 seeds ever year. Squirrels not only consume the nuts but also bury them; fortunately, they do not remember where they put them all.

The lightweight seeds of elm, ash, and basswood have so little food in them, that wildlife eat them rather than store them. In their case, the trees have to depend on the wind to disperse their seed.

The forester uses natural regeneration by selecting an area that has two characteristics:

(1) many seedlings and saplings of desirable species and

(2) a canopy layer of undesirable species.

By removing the undesirable larger trees, the canopy is opened to let in the sunlight. Some of the young saplings have struggled in the understory, starved for sunlight for 40 years. By opening the canopy, these saplings will begin to compete for the sunlight, growing fast and tall.