ICAR AICE-JRF/SRF Stand Tending, Thinning & Pruning: practice questions

Question 1 · medium

When is weeding most valuable in seasonally dry tropical plantations?

1. Immediately after the dry season ends, when weeds are dormant and easy to cut
2. Before the dry season, so that the crop has the remaining soil moisture to itself
3. Only in the year of final felling, to make extraction of logs easier for crews working in the stand
4. Only once per rotation, at the time of the first commercial thinning

Question 2 · medium

Why do heavy canopy openings from logging, fire or grazing often increase climber problems?

1. Climbers need full shade and so move into the darkest remaining patches
2. Canopy openings remove all climber seeds from the soil seed bank
3. Climbers respond strongly to increased light and disturbance
4. Logging machinery spreads climber pollen, which kills crop seedlings

Question 3 · medium

Langsaeter's curve states that, over a wide middle range of stand density:

1. Gross volume increment rises in direct proportion to tree number
2. Height growth usually falls linearly as density rises
3. Roughly constant gross increment per ha
4. Mortality is zero whatever the stand density

Question 4 · hard

Using Reineke's SDI = N × (Dq/25.4)^1.605, what is the SDI of a stand with 900 trees/ha and a quadratic mean diameter of 30 cm?

1. About 1,063
2. About 1,176
3. About 900
4. About 762

Question 5 · hard

The removed trees in a thinning average 18 cm diameter and the stand averaged 24 cm before thinning. What is the thinning ratio d/D and the type of thinning?

1. 1.33, a crown thinning
2. 0.75, a crown thinning
3. 1.33, a low thinning
4. 0.75, a low thinning

Question 6 · hard

How does sanitation cutting differ from salvage cutting?

1. Sanitation removes only healthy trees; salvage removes only trees of unwanted species in mixed natural forests of the tropics and subtropics
2. Sanitation is done only in nurseries; salvage is done only in mangroves
3. Sanitation removes infested or susceptible trees to protect the stand; salvage recovers value from trees already killed or damaged
4. Sanitation is a type of pruning; salvage is a type of weeding

Question 7 · easy

Green pruning differs from dry pruning in that it:

1. Removes dead branches only
2. Removes live branches and so reduces leaf area and possibly growth
3. Is done only with chemical sprays
4. Is done only on seedlings in the nursery before they are lifted and graded for planting

Question 8 · hard

Why may simple girdling fail on some species?

1. They sprout from the stump or roots, or bridge narrow girdles with callus
2. Their bark is too thin to be cut with an axe
3. Their roots do not need sugars from the crown because they photosynthesise below ground
4. They lack a cambium layer entirely

Question 9 · easy

Boron deficiency in pines on some soils is associated with:

1. Leader dieback and stem deformity
2. Excessively fast height growth
3. Doubling of cone production
4. Thicker bark at breast height

Question 10 · medium

Why do improvement, salvage and sanitation fellings need clear rules in the working plan?

1. They are outside the regular yield-table sequence, so removals, regeneration and retention must be specified
2. They are always illegal unless approved by a court of law in each case before any tree is felled by the forest officer
3. They can only be done by private contractors from outside the division
4. They produce no timber and so cannot be recorded in any register