Timber Production Management Planning

Harvest Timing

Optimal age for timber yield maximization.

Yield

Amount of timber produced, measured in cunits.

Mean Annual Increment (MAI)

Average growth over the entire measurement period.

Current Annual Increment (CAI)

Growth attained by the stand in a given year.

CAI Formula

CAI = (Y2 - Y1) / (t2 - t1).

MAI Formula

MAI = Yt / t.

Age of Max MAI

Age for optimal production.

CAI Behavior

Maxes early, then declines with age.

MAI Behavior

Maxes later, intersects CAI at peak.

MAI is increasing

If CAI > MAI

Net Return (Nt)

Per-acre return at harvest after costs.

Stumpage Price (S)

Price per cunit of timber, $35.

Regeneration Cost (R)

Cost per acre for regeneration

Interest Rate (i)

Inflation-free rate, 4%.

Annual Tax (T)

Annual cost per acre, $1.50.

Present Value of Nt

Nt discounted over time, PV = Nt / (1+i)^t.

Bare Land Value (BLV)

Present value of net returns from rotations in a continuing series.

Optimum Rotation Age

Age where MAI is maximized for yield.

Max BLV Age

Age for economic rotation.

Yield Curve

Graph showing yield against age of stand.

Cunits

Unit of measure for timber yield.

Average Production

2.0363 cunits/acre/year at max MAI.

CAI Values

Growth rates for specific ages of timber.

MAI Value

Average growth rates for specific ages.

Net Return Calculation

Nt = SYt - R(1+i)^t - T(1+i)^(t-1).

Present Value Calculation

PV = Nt / (1+i)^t.

Maximum Yield Age

Age to obtain highest average production.

Economic Rotation Age

Age where BLV is maximized.