How Woodlands Grow
A tree seed germinates, a seedling emerges, it is browsed by a deer, it grows to a sapling, a bird nests in its branches. When it is a pole-sized tree, wind breaks a branch. When mature, it is felled by a logger. In the vacant space left behind, a seed germinates, but it?'s of a different tree species than the felled tree, and the forest changes.
This process of change, in which a collection of tree species is slowly replaced by a different collection of tree species is called succession. Forestry is the art and science of manipulating a woodland to achieve your personal goals. Forestry can speed up or slow down natural succession. Your management may affect the characteristics of your woodland for a century or much longer, so it is wise to consider the long-term impacts of your decisions. Doing nothing may not yield the outcome you want to see. Future owners and others who depend on your resources will live with the consequences of your management practices.
The basic unit of management is a stand. It is common practice for a forester to develop a set of management practices for each stand based on the owner?fs objectives. Woodland owners often have different objectives for different stands because their growth potential may be different.
The growth potential of a stand is partly affected by the mix of tree species growing on it, but in the long term, growth potential is governed by the underlying site characteristics: soil, moisture, topography, and climate. Each stand in a woodland has an ecological trajectory, a natural pathway for change, that is heavily influenced by site characteristics. This pathway can be altered and the species composition of a stand changed via natural disaster (such as a fire or windstorm) or human activities (such as harvesting, thinning, or introducing invasive exotic species). To simplify management and reduce costs, you ordinarily should encourage growth of tree species that are naturally adapted to the site characteristics.