Thinning timber in Alabama can earn 350 per acre and increase annual harvest by 25%

That’s a tough pill to swallow for one that doesn’t understand the dynamics of thinning planted pine. This thinning timber stands is an actual case I recently looked at in Alabama. The planted pine had never been thinned, so we are talking about a first time thinning.

There were 450 trees per acre (tpa) which is fairly normal for a first time thinning. A typical Alabama planting will be a 6×10 spacing yielding 726 seedlings per acre. And normal mortality will result in about 450 trees per acre by the time the stand is ready to be thinned. This is another fact that landowners generally do not realize since 450 tpa give a deceptive impression to the layman that not a single tree has died since the day they were planted.

In thinning this stand of planted pine, 250 tpa are removed during the harvest, leaving 200 residual trees that will become future high-value crop trees. This assumes a fourth row thinning, which means every 4th row is to be completely removed, taking 100% of the trees in that row, giving room to cut take-out trees in the remaining rows and a lane to skid the cut trees to a loading ramp. So the fourth row is thinned unselectively and the remaining three rows between are thinned by selecting the weaker, slower growing, diseased, and deformed trees to be removed. The 200 best trees (65-70 square feet of Basal Area) are selected for their future higher-value-solid-wood-products potential to remain growing on the property.

The stand is growing at 3.3 tons per acre per year (1.25 cords/acre volume growth potential). The product ratio within the stand is 2/3 pulpwood trees and 1/3 chip-n-saw. Assuming $7 per ton for pulpwood and $15 for chip-n-saw, the annual value growth for the existing 450 trees per acre is $31.86/acre/year.

Now assume the dirt has the same potential for growing the remaining 200 trees per acre following the thinning. Also assume we have a new product ratio of 37.5% pulpwood and 62.5% chip-n-saw. This new growth on the remaining higher value wood will yield $39.58/acre/year.

Consider the current dollar growth on this stand compared to the potential of the new growth and you get an increase in annual value of 24.2% or nearly 25 percent. So there you have it; this landowner could thin his trees, collect better than $350 per acre now and enjoy an increase in annual value growth by nearly 25%. This should be a no-brainer timber management decision to thin.