I85PREP
⌘ K
Lok Sewa Forestry Officer study materials
Lok Sewa Forestry Officer study resources

Lok Sewa Forestry Officer practice questions

One question at a time. Build your Lok Sewa Forestry Officer understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Forestry Science and Silviculture

In silviculture, which regeneration method relies on seed fall from retained mother trees scattered across the harvested area?

  1. Clear felling with artificial planting
  2. Shelterwood strip system
  3. Coppice with standards
  4. Seed tree system Correct answer.

Explanation

The seed tree system leaves a small number of mature trees per hectare to provide seed for natural regeneration, after which they are usually removed once regeneration is established. It differs from shelterwood, which retains a denser overstorey in successive fellings to shelter seedlings.

Question 2Forestry Science and Silviculture

Which tree species is a typical nitrogen-fixing associate used in Nepali silviculture to improve soil fertility?

  1. Shorea robusta
  2. Dalbergia sissoo
  3. Pinus roxburghii
  4. Alnus nepalensis Correct answer.

Explanation

Alnus nepalensis forms root nodules with the actinomycete Frankia and fixes atmospheric nitrogen, so it is widely used as a nurse and soil-improving species. The other species listed do not form effective nitrogen-fixing symbioses.

Question 3Forestry Science and Silviculture

What does the site quality class of a forest stand primarily indicate?

  1. The market value of standing timber
  2. The volume of timber already harvested from the stand
  3. The current stocking density of seedlings
  4. The productive capacity of the site for a given species Correct answer.

Explanation

Site quality expresses the inherent productive potential of a site, commonly indexed by dominant height at a reference age. It is independent of past harvest volume, present seedling density, or timber prices.

Question 4Forestry Science and Silviculture

In nursery practice, what is the main purpose of root pruning of seedlings before lifting?

  1. To promote a compact, fibrous root system for better survival Correct answer.
  2. To induce early flowering
  3. To reduce the need for watering
  4. To increase shoot elongation

Explanation

Root pruning undercuts long taproots and stimulates lateral fibrous roots, improving the root-to-shoot ratio and field survival after outplanting. It does not promote shoot growth or flowering.

Question 5Forestry Science and Silviculture

Which silvicultural system is best described as regenerating a stand by vegetative sprouts from cut stumps?

  1. Seed tree system
  2. Coppice system Correct answer.
  3. Selection system
  4. High forest system

Explanation

The coppice system depends on stump sprouts and root suckers for the next rotation, so it is suited to species with strong vegetative reproduction. High forest systems, including seed tree and selection, rely on seed regeneration.

Question 6Forestry Science and Silviculture

Which thinning removes trees of poor form, disease, or inferior crown class to improve the stand?

  1. Improvement thinning Correct answer.
  2. Crown thinning
  3. Free thinning
  4. Mechanical thinning

Explanation

Improvement thinning, also called cleaning when applied to young stands, removes wolf trees, diseased stems, and badly formed individuals to favour desirable trees. Mechanical thinning is based on spacing, free thinning on releasing selected crop trees, and crown thinning on removing competitors of the dominant crown classes.

Question 7Forestry Science and Silviculture

Which soil property is most directly improved by adding forest leaf litter and humus?

  1. Bulk density increase
  2. Soil pH alkalinity
  3. Cation exchange capacity Correct answer.
  4. Particle size of sand

Explanation

Humus from decomposing litter has high surface area and negative charge, raising cation exchange capacity and nutrient retention. It generally lowers bulk density and does not change the sand fraction or make soils alkaline.

Question 8Forestry Science and Silviculture

In a forest inventory, what does the term basal area per hectare express?

  1. Cross-sectional area of stems at breast height per hectare Correct answer.
  2. Total stem volume per hectare
  3. Number of seedlings per hectare
  4. Mean crown diameter per hectare

Explanation

Basal area per hectare is the sum of stem cross-sectional areas measured at breast height (usually 1.3 m) over a unit area, commonly in square metres per hectare. It is a measure of stand density and is distinct from volume, stem count, or crown dimension.

Question 9Forestry Science and Silviculture

A plantation of a light-demanding species is established under a partial overstorey that is removed after two years. Which silvicultural technique does this describe?

  1. Coppice regeneration
  2. Direct seeding in the open
  3. Nurse crop shelter Correct answer.
  4. Group selection felling

Explanation

Using a temporary overstorey to protect a young plantation from frost, sun, or weeds, then removing it, is a nurse crop or shelter technique. Direct seeding in the open lacks the protective cover, and the other options are regeneration methods rather than protection of planted stock.

Question 10Forestry Science and Silviculture

A stand has a dominant height of 24 m at base age 50 years and the site index curve for the species gives 24 m at index age 50. What is the site index?

  1. 48
  2. 50
  3. 24 Correct answer.
  4. 12

Explanation

Site index is defined as the dominant height reached at the reference (index) base age, here 50 years. Since the measured dominant height at that age is 24 m, the site index is 24.

Question 11Forestry Science and Silviculture

In a 0.1 hectare circular plot, 15 stems of a species are counted. What is the stems-per-hectare value for that species?

  1. 1500
  2. 150 Correct answer.
  3. 1.5
  4. 15

Explanation

Stems per hectare equals the plot count multiplied by the expansion factor 1/plot area in hectares. Here 15 stems in 0.1 ha gives 15 × 10 = 150 stems per hectare.

Question 12Forestry Science and Silviculture

A forester wants to release a valuable shade-tolerant crop tree from competition while retaining continuous canopy cover. Which treatment is most appropriate?

  1. Coppicing the crop tree
  2. Crown thinning around the crop tree Correct answer.
  3. Clear felling
  4. Prescribed burning of the understorey

Explanation

Crown thinning removes immediate competitors of selected crop trees while keeping the main canopy, which suits shade-tolerant species and continuous cover objectives. Clear felling removes canopy cover, fire damages the site, and coppicing would destroy the selected stem.

Question 13Forestry Science and Silviculture

Which condition most favours successful natural regeneration of a heavy-seeded species such as oak?

  1. Exposed mineral soil with adequate moisture and nearby seed source Correct answer.
  2. Waterlogged soil throughout the growing season
  3. Deep litter accumulation with no disturbance
  4. Complete removal of all overstorey trees before seed fall

Explanation

Heavy seeds disperse short distances and establish best on moist mineral soil where litter is reduced and a seed source is close. Deep litter hinders contact with soil, premature overstorey removal removes shelter, and waterlogging restricts root aeration.

Question 14Forestry Science and Silviculture

Why is a mixture of a nitrogen-fixing species with a commercial timber species often used in plantation design?

  1. To improve nutrient status and canopy structure Correct answer.
  2. To shorten the rotation of the timber species to one year
  3. To eliminate the need for thinning
  4. To reduce total stand basal area

Explanation

Mixtures with nitrogen-fixing species can add nitrogen, improve litter quality, and diversify canopy structure, supporting the growth of the companion crop. They do not remove the need for thinning or shorten rotations to implausible lengths.

Question 15Forestry Science and Silviculture

A forester marks trees for felling using a diameter limit of 40 cm. Which silvicultural concern does this rule raise in an uneven-aged stand?

  1. It removes the fastest-growing young trees
  2. It prevents any regeneration from occurring
  3. It may remove the vigorous large trees needed as seed bearers Correct answer.
  4. It eliminates all suppressed stems

Explanation

A simple diameter limit ignores vigour, form, and age, so it can remove the large, well-formed trees that provide seed and maintain stand structure. It does not selectively remove young fast growers, and it has no direct bearing on whether regeneration occurs.

Question 16Forestry Science and Silviculture

Which factor most strongly determines the choice between natural regeneration and artificial regeneration for a given site?

  1. Age of the forest ranger
  2. Number of visitors to the forest
  3. Availability of viable seed and reliable establishment conditions Correct answer.
  4. Colour of the mature foliage

Explanation

Natural regeneration is feasible only where seed sources, seedbed conditions, and adequate protection exist; otherwise planting or sowing is chosen. Foliage colour, visitor numbers, and staff age do not determine the regeneration method.

Question 17Forestry Science and Silviculture

What is the primary silvicultural objective of a cleaning operation in a young stand?

  1. To mark trees for final felling
  2. To remove undesirable vegetation competing with favoured seedlings Correct answer.
  3. To harvest the first commercial timber yield
  4. To establish a new rotation after clear felling

Explanation

Cleaning removes weeds, climbers, and unwanted woody growth that compete with young crop seedlings for light, water, and nutrients. It precedes commercial thinning and is not a harvesting or final-felling operation.

Question 18Forestry Science and Silviculture

Which statement best explains why shelterwood regeneration often produces better seedling survival than clear felling on exposed sites?

  1. The overstorey prevents all seed production
  2. The overstorey increases soil temperature to extreme levels
  3. The overstorey reduces frost, desiccation, and weed competition Correct answer.
  4. The overstorey eliminates the need for any tending

Explanation

Retained shelterwood trees moderate microclimate by reducing frost damage, wind desiccation, and weed growth, which improves seedling survival on exposed sites. The overstorey does not prevent seed production and does not remove the need for tending.

Question 19Forestry Science and Silviculture

A stand is to be managed on a 40-year rotation with thinnings scheduled at ages 15 and 25. What is the main purpose of the thinning at age 25?

  1. To remove all dominant trees
  2. To convert the stand to coppice
  3. To regenerate the stand naturally
  4. To concentrate growth on the best remaining stems Correct answer.

Explanation

Intermediate thinnings remove suppressed and competing trees so that growing space and site resources are concentrated on the best stems, improving final crop quality. They are not regeneration fellings and do not remove the dominant trees that form the future crop.

Question 20Forestry Science and Silviculture

Which measure best reduces the risk of a plantation failing from frost on a valley floor site?

  1. Choosing a frost-hardy species and planting on a raised microsite Correct answer.
  2. Planting frost-tender species in the lowest hollow
  3. Removing all vegetation before planting
  4. Increasing the planting density to the maximum

Explanation

Frost damage is worst in cold-air pools on valley floors, so selecting hardy species and planting on raised mounds or frost-free slopes reduces risk. Dense planting or bare soil does not remove the cold-air hazard.

Question 21Forestry Science and Silviculture

Which of the following best describes the difference between a silvicultural system and a silvicultural treatment?

  1. A system is the overall plan for regeneration and tending; a treatment is a specific operation within it Correct answer.
  2. A system is a single felling; a treatment is a rotation
  3. A system applies only to plantations; a treatment applies only to natural forests
  4. A system is a soil type; a treatment is a species

Explanation

A silvicultural system integrates the regeneration method, cutting pattern, and tending regime over a rotation, while a treatment is an individual operation such as a thinning or cleaning. Systems are not restricted to plantations, and neither term denotes soil or species.

Question 22Forestry Science and Silviculture

In a stand table, a species shows 200 stems per hectare with a mean basal area of 0.05 square metres per stem. What is the stand basal area?

  1. 40 square metres per hectare
  2. 4 square metres per hectare
  3. 100 square metres per hectare
  4. 10 square metres per hectare Correct answer.

Explanation

Stand basal area equals stems per hectare multiplied by mean basal area per stem, so 200 × 0.05 = 10 square metres per hectare. This is a standard stand-table calculation.

Question 23Forestry Science and Silviculture

A manager proposes converting a degraded coppice stand to high forest. Which sequence is silviculturally sound?

  1. Clear felling and abandoning the site
  2. Retaining selected vigorous shoots as standards and thinning them over successive rotations Correct answer.
  3. Grazing the stand continuously until trees establish
  4. Repeated coppicing at one-year intervals

Explanation

Conversion to high forest requires selecting and retaining vigorous single stems as standards, then gradually thinning and tending them so they develop into seed-bearing trees. Annual coppicing, abandonment, and continuous grazing prevent the development of high-forest stems.

Question 24Forestry Science and Silviculture

Why can a diameter-limit harvest reduce long-term stand productivity even when it removes the same volume as a well-planned thinning?

  1. It always improves soil nutrient status
  2. It removes only suppressed stems that would die anyway
  3. It increases the seed supply for regeneration
  4. It removes the largest and often most vigorous trees, leaving genetically and structurally poorer residuals Correct answer.

Explanation

Diameter-limit or high-grading harvests tend to remove the largest, best-formed, and often most vigorous stems, leaving poorer residual trees and degrading future genetic and structural quality. A planned thinning instead removes competitors while retaining the best crop trees.

Question 25Forestry Science and Silviculture

In an uneven-aged selection forest, why is a balanced diameter distribution important?

  1. It ensures a steady supply of trees in all size classes and continuous regeneration Correct answer.
  2. It guarantees that all trees are of the same age
  3. It prevents any natural mortality
  4. It eliminates the need for inventory

Explanation

A balanced diameter distribution maintains trees across size classes, supporting continuous yield, canopy structure, and regeneration in uneven-aged management. It does not equalise age, prevent mortality, or remove the need for inventory.

Question 26Forestry Science and Silviculture

Which regeneration method relies on seed falling from scattered seed trees retained on the harvested area until seedlings are established?

  1. Strip felling method
  2. Selection method
  3. Seed-tree method Correct answer.
  4. Coppice method

Explanation

The seed-tree method leaves a small number of mature, wind-firm trees per hectare to provide seed, then removes them once regeneration is secured. It suits light-demanding species with reliable seed years and requires a seed source that survives exposure.

Question 27Forestry Science and Silviculture

What does the site index of a forest stand express?

  1. Top height attained by the dominant trees at a specified reference age Correct answer.
  2. Depth of the effective rooting zone above any restricting layer
  3. Total volume produced per hectare over the whole rotation
  4. Number of naturally regenerated seedlings per hectare after germination

Explanation

Site index is a height-based measure of site productivity, expressed as the top height of dominant trees at a chosen base age. Height is used because it is less sensitive than volume to stocking and thinning history.

Question 28Forestry Science and Silviculture

Which practice is the standard way to raise the germination percentage of a seedlot of a species with hard, impermeable seed coats?

  1. Sowing the seed deeply in compacted nursery beds
  2. Soaking the seed in a dilute fungicide suspension
  3. Storing the seed dry at low temperature for several weeks
  4. Scarifying the seed coat mechanically or with acid before sowing Correct answer.

Explanation

Hard-seeded species show physical dormancy because water cannot enter through the impermeable coat. Scarification opens the coat so imbibition can begin, which raises the proportion of seeds that germinate.

Question 29Forestry Science and Silviculture

What is the principal purpose of a tending operation that cuts back competing vegetation around young seedlings without removing the overstorey?

  1. To increase the volume of the final crop by reducing the rotation length
  2. To reduce competition for light, water and nutrients so that seedlings become established Correct answer.
  3. To create dead wood for cavity-nesting birds
  4. To raise the stocking above the level set at planting

Explanation

Weeding or release from competing vegetation reduces resource competition during the vulnerable establishment phase. Survival and early height growth improve because seedlings gain access to light, moisture and nutrients.

Question 30Forestry Science and Silviculture

A forester needs to estimate the volume of standing timber in a compartment. Which combination of measurements is required to apply a standard volume equation for a single tree?

  1. Diameter at breast height, age and crown width
  2. Basal area per hectare, stems per hectare and site index
  3. Diameter at breast height, total height and a species-specific form factor Correct answer.
  4. Total height, canopy cover and slope

Explanation

Tree volume is derived from basal area, height and a form factor that corrects for taper. Species-specific form factors or volume tables convert these field measurements into volume estimates.

Question 31Forestry Science and Silviculture

Which thinning method removes trees from all crown classes across the stand in a single operation, aiming to reduce density uniformly?

  1. Free thinning
  2. Geometric thinning Correct answer.
  3. Low thinning
  4. Crown thinning

Explanation

Geometric thinning, also called mechanical or schematic thinning, removes a fixed proportion of stems at regular spacing regardless of crown class. It is simple to mark and apply but does not preferentially favour the best trees.

Question 32Forestry Science and Silviculture

A nursery manager wants to harden seedlings before outplanting on a dry site. Which measure most directly improves drought hardiness of the planting stock?

  1. Applying a broad-spectrum insecticide shortly before lifting
  2. Reducing irrigation and nitrogen supply while maintaining adequate phosphorus and potassium Correct answer.
  3. Increasing irrigation frequency in the final weeks before lifting
  4. Shading the seedbeds heavily to lower leaf temperature

Explanation

Reducing water and nitrogen in the hardening phase encourages stocky growth, greater root-to-shoot ratio and stomatal control. Adequate phosphorus and potassium support root development and stress tolerance without promoting soft shoot growth.

Question 33Forestry Science and Silviculture

In a forest survey, what does the term crown ratio describe?

  1. The number of whorls of branches produced in the current growing season
  2. The ratio of crown width to stem diameter at breast height
  3. The fraction of the stand area covered by the canopy when viewed from above
  4. The proportion of total tree height that carries live crown Correct answer.

Explanation

Crown ratio is the live crown length expressed as a proportion of total tree height. It is used as an indicator of tree vigour and of the effect of thinning and competition.

Question 34Forestry Science and Silviculture

A plantation established on an exposed ridge shows poor height growth and yellowing foliage despite adequate rainfall. Which site factor should be investigated first?

  1. Rotation length set in the management plan
  2. Age of the seedlot used in the nursery
  3. Soil nutrient status and pH of the rooting layer Correct answer.
  4. Spacing used at the time of planting

Explanation

Yellowing with poor growth on an exposed site commonly indicates nutrient deficiency, often nitrogen or phosphorus, or an unsuitable pH. Soil sampling and foliar analysis are the appropriate first diagnostic steps.

Question 35Forestry Science and Silviculture

A stand is regenerated by clear felling followed by planting. Which measure best protects the site from nutrient loss and erosion in the first two years?

  1. Retaining harvest residues and establishing a rapid ground cover Correct answer.
  2. Deep cultivation of the whole area to bury the litter layer
  3. Delaying planting until the second growing season
  4. Complete removal of harvest residues by burning

Explanation

Retaining slash and establishing early ground cover protect the soil surface from raindrop impact and reduce leaching of nutrients released after felling. Burning residues removes organic matter and exposes mineral soil.

Question 36Forestry Science and Silviculture

Which statement best describes the difference between a silvicultural system and a silvicultural treatment?

  1. A system is applied once at stand establishment, while a treatment is repeated every year
  2. A system defines the overall regeneration and tending framework, while a treatment is a specific intervention within it Correct answer.
  3. A system applies only to even-aged stands, while a treatment applies only to uneven-aged stands
  4. A system is a legal designation, while a treatment is a technical prescription

Explanation

A silvicultural system is the whole sequence of operations that regenerates and tends a stand, such as shelterwood or selection. Treatments are the individual interventions, such as a thinning or a cleaning, carried out within that framework.

Question 37Forestry Science and Silviculture

A manager wants to convert a degraded coppice stand to high forest. Which first step is silviculturally sound?

  1. Continuing short coppice rotations until the stools die out
  2. Clearfelling the whole stand and planting a single fast-growing species
  3. Selecting and releasing the best stems from seed origin to form the future crop Correct answer.
  4. Removing all advance growth to simplify later marking

Explanation

Conversion begins by identifying and releasing good-quality seedlings and saplings of seed origin so that they can develop into the future high forest. This builds a seedling-derived component while the coppice canopy is gradually opened.

Question 38Forestry Science and Silviculture

A forester compares two compartments with identical basal area per hectare, but one has many small stems and the other fewer large stems. Which additional measure best distinguishes their structure?

  1. Canopy cover percentage
  2. Total height of the tallest tree
  3. Quadratic mean diameter Correct answer.
  4. Site index

Explanation

Quadratic mean diameter summarises the average size of stems and reveals whether a given basal area is carried by many small trees or fewer large ones. Basal area alone cannot distinguish these structural differences.

Question 39Forestry Science and Silviculture

In a shelterwood system, why is the final removal of the overstorey usually delayed until the regeneration is well established?

  1. Because the final felling is legally restricted to winter months
  2. Because seed production stops once the overstorey is removed
  3. Because the overstorey shelters seedlings from frost and drought while they develop root systems Correct answer.
  4. Because seedlings need full overhead cover throughout their rotation

Explanation

Retained overstorey trees moderate temperature extremes, reduce frost damage and limit weed competition while seedlings develop. Once the regeneration is robust, the overstorey is removed to release it into full light.

Question 40Forestry Science and Silviculture

A selection forest shows a shortage of stems in the smallest diameter classes while the large classes are over-represented. What is the most likely long-term consequence if harvesting continues unchanged?

  1. The basal area will automatically stabilise at the target level
  2. The growing stock will become increasingly concentrated in large trees and recruitment will fail Correct answer.
  3. The site index of the stand will decline sharply
  4. The stand will rapidly convert to an even-aged structure

Explanation

A deficit of small stems means insufficient recruitment to replace harvested large trees, so growing stock becomes concentrated in large size classes. Over time the diameter distribution becomes unbalanced and sustained yield cannot be maintained.

Question 41Forest Management and Forest Mensuration

In forest mensuration, a standing tree's diameter at breast height (DBH) is conventionally measured at what height above the ground on level terrain?

  1. 2.0 m
  2. 1.3 m Correct answer.
  3. 0.5 m
  4. 3.0 m

Explanation

DBH is standardized at 1.3 m above ground level in Nepal and most metric countries so that diameters from different trees and inventories are comparable. Measuring at other heights would break comparability with volume tables and yield equations.

Question 42Forest Management and Forest Mensuration

A forester records a tree's diameter with a caliper as 40.0 cm. If the same tree were measured with a diameter tape, the tape reading would represent which quantity?

  1. Half the caliper reading
  2. Circumference divided by pi Correct answer.
  3. Radius squared times pi
  4. Circumference multiplied by pi

Explanation

A diameter tape is graduated so that the measured circumference is divided by pi, directly giving diameter. This makes the tape reading equivalent to a true diameter, not a circumference.

Question 43Forest Management and Forest Mensuration

A rectangular sample plot measures 20 m by 25 m. What expansion factor converts the number of trees counted in the plot to trees per hectare?

  1. 20 Correct answer.
  2. 40
  3. 25
  4. 50

Explanation

The plot area is 500 m², and one hectare is 10,000 m², so the expansion factor is 10,000/500 = 20. Multiplying the plot count by 20 gives trees per hectare.

Question 44Forest Management and Forest Mensuration

In a fixed-area plot inventory, the basal area per hectare is obtained by multiplying the summed tree basal areas (m²) in the plot by which value?

  1. 10,000 divided by plot area in m² Correct answer.
  2. Plot perimeter divided by area
  3. Number of trees in the plot
  4. Plot area in m² divided by 10,000

Explanation

Basal area per hectare scales the plot total to a hectare basis, so the multiplier is 10,000/plot area in m². This assumes the plot is representative of the stand.

Question 45Forest Management and Forest Mensuration

Which instrument is specifically designed to estimate basal area per hectare directly by variable-radius (angle-count) sampling?

  1. Increment borer
  2. Relascope Correct answer.
  3. Bark gauge
  4. Clinometer

Explanation

A relascope uses a fixed sighting angle so that each counted tree represents a fixed basal area per hectare, allowing rapid stand basal area estimation. The other instruments measure height, age, or bark thickness.

Question 46Forest Management and Forest Mensuration

In point sampling with a metric basal area factor (BAF) of 2 m²/ha, a tree is tallied when its diameter at breast height exceeds which threshold relative to its horizontal distance from the point?

  1. Diameter in cm exceeds the BAF squared
  2. Diameter in cm exceeds twice the distance in m
  3. Diameter in cm exceeds distance in m times 2√2 Correct answer.
  4. Diameter in cm exceeds distance in m divided by the BAF

Explanation

For metric point sampling, BAF = 0.25(D/R)², where D is diameter at breast height in centimetres and R is horizontal distance in metres. Thus the limiting diameter is D = 2R√BAF. With BAF = 2 m²/ha, a tree is tallied when D > 2√2 R, approximately 2.828R.

Question 47Forest Management and Forest Mensuration

A hypsometer reading gives a tree's total height as 24 m. If the horizontal distance from the observer to the tree is 20 m and the base angle was zero, what tangent value was effectively used for the top angle?

  1. 0.24
  2. 20.0
  3. 1.20 Correct answer.
  4. 0.83

Explanation

Height equals distance multiplied by the tangent of the elevation angle, so tangent = height/distance = 24/20 = 1.20. This corresponds to an angle of about 50 degrees.

Question 48Forest Management and Forest Mensuration

When a tree's top and base are both above the observer's eye level, the correct total height from two clinometer readings is obtained by which operation?

  1. Multiplying the two components
  2. Subtracting the base component from the top component
  3. Adding the two height components Correct answer.
  4. Averaging the two components

Explanation

If both points lie on the same side of eye level, the vertical components are additive because the eye level falls below the tree base. Subtraction applies only when one point is above and the other below eye level.

Question 49Forest Management and Forest Mensuration

In a stem analysis, the volume of a felled tree is commonly computed by treating successive short sections as which geometric solid?

  1. Frustum of a cone Correct answer.
  2. Sphere
  3. Hemisphere
  4. Perfect cylinder

Explanation

Tapered sections are best approximated as frustums of a cone using Smalian's or Huber's formula. A cylinder ignores taper and would overestimate volume.

Question 50Forest Management and Forest Mensuration

Using Smalian's formula, the volume of a 4 m log with end diameters of 30 cm and 20 cm is closest to which value?

  1. 0.28 m³
  2. 0.20 m³ Correct answer.
  3. 0.10 m³
  4. 0.16 m³

Explanation

Smalian's formula uses the average of the two end areas times length. The end areas are about 0.0707 m² and 0.0314 m², averaging 0.0511 m², which times 4 m gives about 0.20 m³.