Forest Management Planning and Economics
What this domain tests
Rotation and thinning economics, discounting, appraisal, and the difference between a biologically attractive stand and a financially attractive one.
Core rules
- Discounting: NPV = sum of cash flows divided by (1+r) to the t power. Future costs and revenues shrink fast at high rates, which shortens financially optimal rotations.
- LEV (soil expectation value) values bare land as an infinite series of rotations; it is the correct comparison for land with no timber capital.
- IRR is the rate at which NPV equals zero; comparing IRR to the landowner's alternative rate is the accept or reject test.
- Economic maturity occurs when value growth equals the discount rate, not when mean annual increment peaks.
- Stumpage value = delivered product value minus harvest, haul, and processing costs; a bid below that margin loses money.
- Sensitivity matters: a one percent change in the discount rate can reverse the ranking of two prescriptions.
Worked example
A final harvest of 20,000 dollars is expected in 30 years. At 5 percent, present value is 20,000 divided by 1.05 to the 30th = 20,000 divided by 4.3219 = 4,628 dollars. A thinning yielding 6,000 dollars in 15 years is worth 6,000 divided by 1.05 to the 15th = 2,886 dollars today. Adding a 500-dollar site preparation cost now makes the combined prescription worth 4,628 + 2,886 - 500 = 7,014 dollars.
Traps
Comparing undiscounted totals; mixing nominal cash flows with a real discount rate; ignoring annual management costs; treating LEV as valid for a stand that already holds timber; confusing inflation with real price appreciation.