Brad Withrow-Robinson, Forestry & Natural Resources Extension Agent, Benton, Linn and Polk Counties.
In previous segments I argued that many people have too many trees in their young stands which may be costly and harmful to the long term growth of the stand. Most importantly, having too many trees at this stage can undermine common landowner objectives of growing attractive, longer rotation diverse forest habitats and can force landowners into shorter rotations than imagined.
While this suggests that people should think about planting fewer trees per acre in the future (a step deserving some careful consideration), it highlights the need for pre-commercial thinning in many existing stands to correct overstocking at an early age. This may include your stand.
But pre-commercial thinning (PCT) seems to have fallen out of common practice lately. It has come to be seen (mistakenly, I think) as an avoidable expense rather than an important investment in the stand. An investment that begins to shape how the stand will look and behave in the future and which adds resilience and options to the landowners’ woodland portfolio.
The idea of PCT is to avoid harmful overcrowding later by removing excess trees early on. PCT lets the remaining “leave trees” grow faster and larger before serious crowding sets in. This means that trees reach a usable size sooner, and hopefully allows the very important first thinning harvest (also called a commercial thinning) to be done “on time” when the stand is in its 20’s. This first thinning harvest is costly and the difference between it being another big expense for the landowner rather than breaking even or even paying some small profit, often comes down to the size of the trees harvested. PCT is meant to ensure that this very important thinning harvest operation can pay for itself. Continue reading