Indian Forest Service Examination Stand Tending, Thinning & Pruning: practice questions

Indian Forest Service Examination (IFoS) — Forestry optional · India · Union Public Service Commission

Original practice questions written to the published syllabus · not past papers

6worked here, free

17written to this exam in this subject

10syllabus units

What this subject covers

The intermediate treatments between regeneration and harvest that shape a stand's growth, quality and health.

In the exams: ICAR AICE-JRF 59 Unit 2 (tending: weeding, cleaning, climber cutting, mechanical, ordinary, crown and selection thinning, improvement felling, pruning, girdling); IFoS Forestry Paper I Section A (establishment and tending)

Weeding and cleaning
Climber cutting
Thinning: objectives and effects on growth
Thinning methods: mechanical, ordinary (low), crown, selection
Thinning grades and thinning schedules
Improvement felling and salvage cutting
Pruning: natural and artificial; timing and lift
Girdling and other stand-improvement methods
Release treatments and competition control
Fertilisation of established stands

Where the 17 questions fall

How our questions for Indian Forest Service Examination spread across the units of Stand Tending, Thinning & Pruning. Difficulty: 1 easy, 11 medium, 5 hard.

Weeding and cleaning	2
Thinning: objectives and effects on growth	2
Thinning methods: mechanical, ordinary (low), crown, selection	2
Thinning grades and thinning schedules	2
Improvement felling and salvage cutting	2
Girdling and other stand-improvement methods	2
Fertilisation of established stands	2
Climber cutting	1
Pruning: natural and artificial; timing and lift	1
Release treatments and competition control	1

6 practice questions, worked

Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.

1 · Climber cutting · medium

Why is complete eradication of climbers not usually the aim in natural forest?

Climbers have no effect on tree growth in any natural forest type, so cutting is wasted effort and money for the division
Climbers are protected by law in every country, so they may never be cut in any forest
Lianas contribute to diversity, food supply and wildlife structure; cutting targets crop trees and harvest areas
Climbers disappear on their own within one year after any logging operation

Answer and working

C. Lianas contribute to diversity, food supply and wildlife structure; cutting targets crop trees and harvest areas

Lianas are part of natural forest ecology; cutting is targeted at crop and future crop trees and around harvesting. They do affect tree growth, are not universally protected, and increase after logging.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

2 · Thinning: objectives and effects on growth · medium

If thinning within the middle density range does not raise total volume production, why is it done?

It always doubles total volume production within one thinning cycle on every site
It lowers the cost of final felling to zero because no trees remain at rotation age in the thinned stand
It removes the need for any regeneration after final felling of the stand
It concentrates growth on fewer, larger, more valuable trees and uses trees that would otherwise die

Answer and working

D. It concentrates growth on fewer, larger, more valuable trees and uses trees that would otherwise die

Thinning redistributes growth to fewer, larger stems, which are worth more per cubic metre, and captures mortality as intermediate yield. It does not double production, remove felling costs or replace regeneration.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

3 · Thinning methods: mechanical, ordinary (low), crown, selection · medium

An outrow in a thinning is:

A removed row that serves as an extraction rack, often combined with selective thinning between racks
A row of trees left unthinned along the compartment edge as a windbreak for the stand
A row of seedlings planted outside the plantation boundary to mark the compartment line, often with a stone pillar
A row of the tallest trees retained for seed in the final felling of the crop

Answer and working

A. A removed row that serves as an extraction rack, often combined with selective thinning between racks

Outrows open access for machines and are combined with selective thinning in the rows between. The other definitions are not outrows.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

4 · Improvement felling and salvage cutting · hard

Removing bark-beetle brood trees before the new generation emerges is an example of:

Liberation cutting
Crown thinning
Precommercial thinning
Sanitation cutting

Answer and working

D. Sanitation cutting

Removing infested trees to prevent spread is sanitation. Liberation removes overtopping older trees; crown thinning and precommercial thinning are density treatments.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

5 · Pruning: natural and artificial; timing and lift · medium

Where should a pruning cut be made?

Just outside the branch collar, without leaving a stub and without cutting flush into the stem
Flush with the stem, cutting through the branch collar to leave a smooth surface of the trunk
About 15 cm from the stem, leaving a stub that will dry out and fall off later
Halfway along the branch, so that the remaining stub still carries some leaves

Answer and working

A. Just outside the branch collar, without leaving a stub and without cutting flush into the stem

Cutting at the collar lets the wound close quickly. Flush cuts enlarge the wound and slow healing; long stubs delay occlusion and admit decay.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

6 · Fertilisation of established stands · medium

Which is the most reliable way to confirm that fertilising a stand will pay?

Visual inspection of bark colour from a distance by an experienced forest guard
Field trials that measure growth response, supported by foliar analysis
The price of fertiliser in the local market
The age of the oldest tree in the stand

Answer and working

B. Field trials that measure growth response, supported by foliar analysis

Foliar analysis against critical levels and especially field trials show whether a nutrient is limiting and how much growth responds. Bark colour, price and age do not diagnose deficiency.

Further reading: Smith et al., The Practice of Silviculture (9th ed., 1997); Nyland et al., Silviculture (3rd ed., 2016); Khanna, Principles and Practice of Silviculture

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