Selective Timber Harvesting
A selective timber harvest is part of a silvicultural system used to create or maintain an uneven-aged forest. Such a forest contains at least three well-defined age classes. For example, an oak-hickory forest with a history of timber harvesting in southern Indiana might have an overstory of 60-80 year old trees, a pole stand of 20-30 year old trees, and an understory layer of seedlings. It might look like this:
This woodland was selectively marked by a now retired consulting forester in 1984 and harvested shortly thereafter. Notice the old white oak stump in the foreground from the previous timber harvest. In 2004 I completed another selective marking on the property. The harvesting was finished shortly before these photos were taken in March of 2006. Notice the scattered tree tops on the ground and also the medium-sized sawtimber trees in the background. Also pay attention to the high stocking (density) level with numerous 20-40 year old pole-sized sized trees present. A high stocking level is one of the characteristics of uneven-aged forest management.
One thing that does not show up well in this winter photo is the tree seedling regeneration. Because of the use of a selective harvesting system, this woodland is converting to more shade tolerant tree species in many areas. The predominant tree seedlings are sugar maple, beech, and ash.
Finally, the trees that were harvested in this timber sale were all marked and measured by myself. I use one paint spot on the base of the tree to regulate the harvest, in addition to several paint spots on the stem. You may not see a paint spot on every stump pictured here because it is located on the reverse side of the stump.
Here are some more photos from the same selective timber harvest:
One of the main differences between a good selective timber harvest and a poor one is what is left in the woods after the sale. A typical timber buyer will select just the high value, large diameter tree species for cutting and leave the low value (culls, undesirable species) and small diameter trees in the woods. This type of 'selection' harvesting results in a degraded woodland that has a much lower growth and earnings potential over time.
A true selection harvest TAKES trees in all diameter classes, especially those trees that are unhealthy, overmature, have poor form, or are growing on the wrong site. A true selection harvest LEAVES trees in all diameter classes, especially those trees that are healthy, vigorous, have good form, and are growing on the right site. Notice the high quality 22-26 inch diameter (chest height) black walnut, northern red oak, sugar maple, and American beech left in this woods after I marked a proper selective timber harvest:
You can view a larger size of these images by left clicking on any of the pictures.
Copyright 2006, Dwyer Forestry Consulting