ICAR AICE-JRF/SRF Forest Management & Yield Regulation: practice questions

1 · Rotation: physical, silvicultural, technical, financial, maximum volume · medium

Compared with the rotation of maximum volume production, the financial rotation at a positive interest rate is usually:

1. Longer, because interest makes older trees more valuable each year
2. Identical, because both maximise the same quantity over time
3. Shorter, because waiting has a cost when money earns interest
4. Longer at high interest rates and shorter at low interest rates

2 · Growing stock, density and normal growing stock · hard

Why is the triangle approximation of normal growing stock biased for most species?

1. Real forests always contain more age classes than the rotation allows
2. The approximation ignores bark, which is half of all stem volume
3. The approximation counts each age class twice in the calculation
4. Real stand volume rises along a sigmoid curve, not in proportion to age

3 · Increment and the felling cycle · medium

Shortening the felling cycle in a selection forest generally means:

1. Heavier, less frequent fellings in each coupe
2. No change in felling intensity in each coupe
3. Lighter, more frequent fellings in each coupe
4. Fellings only in years with high timber prices

4 · Yield regulation by area · hard

Why does area control guarantee a normal series of age classes after one rotation regardless of the starting structure?

1. Volume per hectare becomes equal everywhere after the first felling of each coupe
2. Every part of the forest is felled and regenerated exactly once, in equal annual areas
3. Area control fells the oldest stands first, which leaves only young ones
4. Increment equals yield from the first year, which fixes the structure

5 · Yield regulation by volume and increment (e.g. Von Mantel, Hufnagl, Austrian formula) · medium

The check method (méthode du contrôle), developed by Gurnaud and Biolley, regulates the cut in selection forests by:

1. Felling a fixed area each year in strict rotation, roughly equal in size
2. Applying Von Mantel's formula to the oldest trees only
3. Repeated full inventories of growing stock and increment, cutting roughly the measured increment
4. Clear felling whenever the stock exceeds normal

6 · Yield regulation in uneven-aged forests by number of trees and diameter limits · medium

The yield-regulation method developed by Brandis for the teak forests of Burma is an example of:

1. An area method using equal annual coupes in clear-felling systems
2. A linear-programming model maximising net present value
3. A number-of-trees method based on girth classes and passage times
4. A volume formula based on normal growing stock

7 · Yield regulation in uneven-aged forests by number of trees and diameter limits · easy

In a BDq-managed stand, the yield taken over a felling cycle is approximately:

1. The entire basal area above the maximum diameter plus all small trees
2. The growth of the stand back up to its pre-harvest structure
3. Half the stand basal area, whatever the target structure
4. The volume of trees below the exploitable diameter

8 · Yield regulation in uneven-aged forests by number of trees and diameter limits · hard

Why is area control by age class not possible in a true selection forest?

1. Trees of all ages grow intermixed on the same ground
2. Selection forests are too small to divide into coupes
3. Selection forests have no measurable increment at all
4. Selection forests are always on slopes too steep to map

9 · Harvest scheduling and optimisation (linear programming) · easy

In Johnson and Scheurman's Model I formulation, each decision variable is:

1. The area regenerated in one period and harvested in a later one, pooled across stands
2. The price of timber in a given period of the planning horizon
3. The area of an initial stand assigned to a complete regime over the horizon
4. The volume of increment in each age class in each year

10 · Multiple-use and ecosystem management · hard

Ecosystem management differs from traditional output-based management mainly by:

1. Maximising timber yield first and adding conservation only if budgets allow
2. Abandoning all monitoring so that ecosystems can manage themselves
3. Managing each stand in isolation without regard to the landscape
4. Sustaining ecosystem composition, structure and function, from which outputs follow