Home    
1 Definition of a Silvicultural System 4 The Decision Process Appendix 1 Answer Key
2 Major Types of Systems 5 There's More to Learn Appendix 2 Advantages and Disadvantages
3 Variations of Major Types 6 Implementation Appendix 3 References

Uneven-aged Silviculture Systems

Selection system arrow Selection system variations

In the selection system, the only uneven-aged system, mature timber is removed either as single scattered individuals or in small groups at relatively short intervals, repeated indefinitely, where an uneven-aged stand is maintained. Regeneration should occur throughout the life of the stand with pulses following harvest entries.

This system depends on recruitment of trees into successive age classes over time and the predictable yield from merchantable age classes. Yield will be obtained by thinning clumps, harvesting individual trees, or by harvesting whole groups of the most mature age class to create small openings scattered throughout the stand.

The selection system can be very complex. Because three variants of selection systems are used and are treated quite differently in BC, these systems are detailed in Chapter 3.

 

spacer graphic

Chapter two icon.

As Swiss foresters tried to transfer German clearcut/even-aged approaches to Switzerland, they encountered problems due to differences in climate, terrain and land tenure. Karl Gayer and Arnold Engler encouraged a more "natural system" in the late 1800s. In 1920, Henri Boilley built on the work of French forester Adolph Gurnaud to develop the "check method," the precursor to the modern selection system.

What about selective logging?

People often confuse the term selective logging with selection system. The term selective logging is still used today by members of the public to describe any harvesting practice that does not clearcut, but rather leaves a significant number of leave-trees. Many foresters resist the use of this term as a synonym for the selection system, or any form of forest management.

In the past selective logging was used to remove the largest, highest quality trees from a stand. Selective logging amounted to mere exploitation, requiring little or no silvicultural skill. This style of cutting did not provide for regulated sustained yield and often resulted in overstocked stands with a deteriorated gene pool. From a long-term management perspective this approach to harvesting was similar to shooting the top three finishers in a horse race and putting the last place horses out to stud.

Selection system harvest stand and ten years after harvest
Selection system after harvest and ten years after harvest

The term selective logging should not be used in silvicultural terminology due to its association with these crude practices. Where a term is sought for all systems that do not include clearcutting, partial cutting systems is more useful and accurate.


Back to top of page.

spacer graphic

 

In the United States so-called "selection" cuttings have been made in various regions and types. In many cases the name is a misnomer, the character of the cutting indicating plainer than words that the selection method is not being employed.
Ralph Hawley (1929)

If selection fellings are to be raised to the status of a silvicultural system, something more is required than the mechanical removal of exploitable trees.
John Mathews (1989)

Quiz time icon.

spacer graphic spacer graphic Previous next