Cutting from below, also known as "ordinary", "German", low thinning, or thinning from below, is the oldest method of forest management through cutting. It is most useful when all the trees in the stand are merchantable. If the smaller trees can notbe easily sold, then it is best to apply a thinning from below later in the stand rotation. we can see in this slide the understory and some of the overstory trees have been removed. Nutrients, light, space, and water are thus freed for use by the remaining trees, leading to an increase in crown and diameter growth.

Low thinnings come in four grades, or intensities, of cutting based on crown class. Crown class is the position and dominance of the tree's crown in the stand. It is generally better to thin on the heavy side in order to cause some effect and not have to go back with frequent, light cuttings. The exception is a salvage cut, where diseased or dead trees are taken out early in the rotation.

This treatment reduces the stocking level to 60% by removing all trees smaller than a certain diameter. Because the decisions about which individual trees toremove are driven by diameter alone, there is no opportunity to deliberately allocate growing space to meet objectives. For
instance, if all the trees on the site are of approximately the same age, a common condition in Pennsylvania, the smaller ones are growing slowlyand competing poorly with their larger neighbors.

Removing them typically provides little additional growing space to the larger ones. Also, by removing all the trees of similar size, we may actually
eliminate one or more tree species that happen to grow and develop naturally at a slower rate.

Though the resulting forest can look almost park-like, which is pleasing to many people, the treatment can have important negative effects. Small trees and shrubs provide food, homes and hiding places for wildlife, and their removal may significantly reduce wildlife use of the area. Also, a diamater-based cut from below will likely not be an economically viable option, in terms of both immediate cash flow and ultimate financial return.

All trees smaller then eight inches in diameter were removed from this block (fig. 2) regardless of species or quality. Even though the stocking level has been reduced to 60%, the growth of the remaining trees is unlikely to improve. These residual trees were already dominant-they had full access to important site resources: light, moisture and nutrients. There is now a higher proportion of shade intolerant species.

This thinning gives the block a pleasing "park-like" appearance. However, some wildlife species are less likely to use this block because shelter and food near the ground are limited. This treatment is not recommended forestry practice, but it does demonstrate results similar to what we might expect following repeated firewood removals, when only small stems are removed.