Stand tending is a subset of silviculture that includes a variety of forest treatments, including pre-commercial thinning, fertilizing, pruning and commercial thinning, which are carried out to maintain a healthy forest and to increase the quality and quantity of timber produced.
Although other silviculture treatments may redistribute volume and/or increase piece size and value, fertilization is the most proven method for increasing harvest volume and accelerating the operability of established stands. As such, fertilization is widely viewed by forest managers and practitioners as a potentially valuable tool for mitigating "pinch points" in the mid-term timber supply caused by age class imbalances, and for increasing long term harvest levels.
Pruning of lower branches of trees in plantations and in pre-commercially thinned stands can increase stand value by reducing the size of the knotty core, thereby increasing the amount and proportion of more valuable clear (knot free) wood. Dimensional lumber that is "clear" of knots and defects has historically commanded premium prices on world markets. Pruning may also improve log and lumber value by speeding the change from lower value juvenile wood to higher value mature wood and by reducing stem taper.
Terminology such as "juvenile thinning," "juvenile spacing," "spacing" and "pre-commercial thinning" generally refers to cuttings made in immature stands with the objective of reducing stand density in order to stimulate the growth of the remaining crop. Thinning affects the size and growth of individual trees and also the growth per unit area of the stand itself. The timing and intensity of juvenile thinning has large potential impacts on the amount, size and value of timber harvested from managed forests and on biological and technical rotation lengths. By preventing, or alleviating, height repression, juvenile thinning in extremely dense stands may provide a more reliable estimate of site potential as represented by site index.
Thinning is the cutting of individual trees from a stand to maintain or improve the health of remaining trees by providing space and resources for growth (e.g., sunlight, water, and nutrients). Commercial thinning refers to an intermediate harvest, as part of a broader stand development pathway, where merchantable volume is removed earlier than final harvest. Thinning can be applied within even-aged stands but can also be used to restore complex stand structures and accelerate forest succession, with a broad goal of preparing stands for uneven-aged silvicultural systems rather than clearcuts.
Thinning is a stand management activity within a silvicultural system practiced in many jurisdictions around the world. Thinning can be used to:
Please direct questions to the Intensive Silviculture Specialist at ThinningSupport@gov.bc.ca
Commercial thinning guidance:
Appropriate training for forest managers is crucial to good forest management. The ministry provides online training resources for forest managers.