This Week: Group Selection

The foresters of Finch Paper use a variety of sustainable forest management techniques, all with a common goal: To keep forests as forests.

In doing so, we help provide a renewable resource that:

• Removes greenhouse gases from our air

• Purifies our water

• Provides diverse biological habitats

• Provides society with the wood for a wide variety of important products that improve our quality of life and keep our planet green.

All of our forest management techniques are based on scientific analyses of what is best for each particular forest based on its tree species, location and other factors. Most importantly, our techniques mimic the changes Mother Nature would otherwise make in the forest over time.

This week, I’d like to give an overview of a management technique called “Group Selection.” You might also call it the “Swiss Cheese Method,” as it leaves small openings scattered throughout the forest just as Mother Nature would when removing individual trees or groups of trees via natural mortality.

Group Selection is typically used in those forests where it is important to the existing ecosystem to maintain some areas of dense forest canopy, and where the tree species are wholly or partially shade tolerant. We may want this canopy to provide shade for water bodies or habitat for specific bird species.  This technique cannot be used in all forest types because Mother Nature evolved some tree species to require full sunlight for regeneration (“shade intolerant” species).

To understand Group Selection, picture a 100-acre forest with a stream running through the middle, divided into 400 quarter-acre plots. Our foresters send timber harvesters into the forest every 15 years or so. Each time they will harvest all of the trees from 50 different quarter-acre plots spread evenly across the landscape. At the end of a 120-year period, each of the 400 plots will have been harvested, and new trees of varying ages will be growing across the forest. Throughout the 120-years, a majority of the 100-acre forest will have a dense canopy.  At the end of the first 120 years the process would begin again.

Forest productivity is less under this system than might be achieved with a system such as the “Shelterwood System,” but the lower growth rate is a trade-off for improved ecosystem benefits.  Remember that this system can only be used in areas where shade tolerant tree species occupy the forest.

As with all of our sustainable forest management techniques, “Group Selection” helps the forest perpetually regenerate, and creates an important source of income for the forest owner so that he can afford to keep the forest as forest and not convert it for development purposes.

In my next posting, I’ll take a look at the often important — and more often misunderstood — clearcut.

Tags: Harvesting, Sustainable Practices