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Master Craftsman Forestry study materials
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Master Craftsman Forestry practice questions

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Question 1Forest Ecology and Silviculture

In silviculture, which term describes a stand of trees established from seed rather than from stump or root sprouts?

  1. Shelterwood
  2. Plantation
  3. Coppice forest
  4. High forest Correct answer.

Explanation

A high forest is a stand originating from seed, so each stem is a distinct individual with a seedling origin. Coppice stands instead arise mainly from vegetative sprouting of cut stumps. The distinction matters because seed-origin stands generally develop a single dominant stem and different wood quality.

Question 2Forest Ecology and Silviculture

A forester wants a light-demanding, wind-dispersed species such as aspen to regenerate after harvest. Which regeneration approach best fits its silvology?

  1. Single-tree selection
  2. Shelterwood with dense overstory retained
  3. Clearcutting in patches Correct answer.
  4. Group selection with 0.1 ha gaps

Explanation

Light-demanding pioneer species establish best on exposed mineral soil with full sunlight, which patch clearcutting provides. Selection systems keep shade that suppresses these species. Small gaps or dense shelterwood leave too little light for vigorous pioneer establishment.

Question 3Forest Ecology and Silviculture

Which soil horizon is typically the zone of maximum fine-root density and organic matter incorporation in a forest profile?

  1. C horizon
  2. B horizon
  3. A horizon Correct answer.
  4. R horizon

Explanation

The A horizon is the surface mineral layer where organic matter accumulates and where most fine roots and biological activity concentrate. The B horizon is a subsurface accumulation zone, the C horizon is weathered parent material, and the R horizon is unweathered bedrock.

Question 4Forest Ecology and Silviculture

Which measure best expresses the competitive status of a tree relative to its neighbors in a stand?

  1. Site index
  2. Crown class Correct answer.
  3. Stocking percent
  4. Basal area

Explanation

Crown class classifies individual trees by canopy position and crown development, directly reflecting competitive status. Site index describes productivity of the site, while basal area and stocking percent describe stand-level density rather than an individual tree's position.

Question 5Forest Ecology and Silviculture

A manager observes that a stand's basal area has risen while quadratic mean diameter has stayed nearly constant. What does this most likely indicate?

  1. Change in species composition
  2. Ingrowth of many small stems Correct answer.
  3. Reduction in site index
  4. Mortality of dominant trees

Explanation

Basal area can rise without a shift in quadratic mean diameter when many small stems are added, since ingrowth adds area while pulling the diameter distribution downward. Mortality of dominants would reduce basal area and can raise mean diameter. Site index is a site property and does not change with stand dynamics.

Question 6Forest Ecology and Silviculture

Which condition most strongly justifies choosing an even-aged system for a shade-intolerant species on a productive site?

  1. Continuous canopy cover is required for soil protection
  2. The owner wants continuous sawtimber harvests every year
  3. The species regenerates well only in full sunlight on exposed soil Correct answer.
  4. Advanced regeneration is already abundant under the canopy

Explanation

Even-aged systems such as clearcutting or shelterwood expose regeneration to the high light that shade-intolerant species require. Uneven-aged systems maintain canopy cover that suppresses such species. The choice should follow the species' regeneration autecology, not harvest convenience alone.

Question 7Forest Ecology and Silviculture

In a shelterwood system, what is the primary purpose of the final removal cut?

  1. To reduce windthrow risk on the stand edge
  2. To release established regeneration from overstory competition Correct answer.
  3. To create advance regeneration before seedfall
  4. To prepare a seedbed by scarifying the forest floor

Explanation

The final removal cut takes off the remaining overstory once regeneration is established, releasing the new cohort from competition for light and water. Seedbed preparation and seedfall belong to the preparatory and seed cuts. Edge windthrow concerns are handled through layout and buffer design.

Question 8Forest Ecology and Silviculture

A stand is described as fully stocked at 100 percent. What does this most directly mean?

  1. Site index equals the regional average
  2. Every tree is of sawtimber size
  3. The canopy is closed with no gaps
  4. The stand's basal area equals the reference value for that density and species Correct answer.

Explanation

Stocking percent compares a stand's density, commonly via basal area, to a reference standard for the species and site. It is a relative density measure, not a statement about tree size or canopy gaps. A stand can be fully stocked without uniform closure or uniform tree size.

Question 9Forest Ecology and Silviculture

Which pair correctly matches a shade-tolerance class with a typical silvicultural implication?

  1. Intolerant species - suited to selection systems
  2. Tolerant species - suited to clearcutting
  3. Tolerant species - suited to uneven-aged management Correct answer.
  4. Intolerant species - require dense shelterwood

Explanation

Shade-tolerant species can regenerate and persist beneath a partial canopy, making them compatible with uneven-aged systems. Intolerant species need exposed, high-light conditions and are poorly suited to selection or dense shelterwood. Matching tolerance to system is a core silvicultural principle.

Question 10Forest Ecology and Silviculture

A forester wants to estimate site productivity for a species using site index. Which data are essential?

  1. Species composition and canopy closure
  2. Soil pH and depth to bedrock
  3. Total stand basal area and stocking percent
  4. Tree age and height of dominant trees Correct answer.

Explanation

Site index is based on the height of dominant or codominant trees at a reference age, because height growth is relatively insensitive to stand density. Basal area, stocking, and canopy closure describe density rather than site quality. Soil properties influence productivity but are not the site index inputs.

Question 11Forest Ecology and Silviculture

Which process in the forest nitrogen cycle converts ammonium to nitrate and is carried out by specialized soil microorganisms?

  1. Denitrification
  2. Ammonification
  3. Nitrogen fixation
  4. Nitrification Correct answer.

Explanation

Nitrification is the microbial oxidation of ammonium to nitrite and then nitrate. Ammonification releases ammonium from organic matter, fixation converts atmospheric nitrogen to usable forms, and denitrification returns nitrate to nitrogen gas. Each step is mediated by different organisms.

Question 12Forest Ecology and Silviculture

Which treatment is a direct release operation in a young plantation?

  1. Cutting competing vegetation around crop trees Correct answer.
  2. Pruning lower branches for clear wood
  3. Prescribed burning of harvest slash
  4. Thinning from below in a mature stand

Explanation

Release removes competing vegetation that suppresses crop trees, directly improving their access to light, water, and nutrients. Thinning and pruning are later tending operations on established trees, and slash burning addresses fuels rather than crop-tree competition.

Question 13Forest Ecology and Silviculture

A manager plans a seed-tree cut. Which condition most limits the reliability of this method?

  1. The site has adequate moisture
  2. The species produces heavy seed with poor dispersal Correct answer.
  3. The species is moderately shade-tolerant
  4. The species is wind-pollinated

Explanation

Seed-tree cuts rely on a few retained trees to disperse seed across the opening, so heavy seed with poor dispersal limits effective regeneration. Wind pollination and adequate moisture aid reproduction rather than hinder it. Moderate shade tolerance does not by itself undermine the method.

Question 14Forest Ecology and Silviculture

Which statement best describes the role of coarse woody debris in forest ecology?

  1. It is a major source of atmospheric methane in uplands
  2. It prevents all surface erosion regardless of slope
  3. It accelerates soil acidification to harmful levels
  4. It provides habitat and slowly releases nutrients and moisture Correct answer.

Explanation

Coarse woody debris supplies habitat for invertebrates and vertebrates, moderates moisture, and releases nutrients as it decays. It contributes to erosion control but cannot prevent all erosion on steep slopes. Its overall effect is ecological enrichment rather than harm.

Question 15Forest Ecology and Silviculture

Which thinning method removes trees from the lower crown classes to favor dominants and codominants?

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

Explanation

Low thinning removes suppressed and intermediate trees from the lower crown classes, leaving dominants and codominants. Crown thinning instead targets competitors of crop trees in the upper canopy. Selection thinning removes large dominants, which is a different objective.

Question 16Forest Ecology and Silviculture

A stand has a site index of 22 m at base age 50 for the target species. What does this value represent?

  1. Height of dominant trees at age 50 Correct answer.
  2. Mean height of all trees at age 50
  3. Total basal area at age 50
  4. Average diameter at age 50

Explanation

Site index is the height reached by dominant or codominant trees at a specified base age, here 50 years. It uses dominant height because that measure is relatively independent of stand density. Basal area and diameter are density- and competition-sensitive and are not site index values.

Question 17Forest Ecology and Silviculture

Which scenario best illustrates the principle of ecological succession in a managed forest?

  1. A clearcut is planted with the same species that was harvested
  2. A plantation is fertilized to increase growth
  3. An abandoned field progresses from grasses to shrubs to pioneer trees to tolerant forest Correct answer.
  4. A stand is thinned to a target basal area

Explanation

Succession is the directional change in community composition over time, as when an old field passes through grass, shrub, and pioneer tree stages toward a tolerant forest. Replanting the same species, thinning, and fertilizing are management interventions rather than successional change.

Question 18Forest Ecology and Silviculture

Which factor most directly determines whether a clearcut will regenerate naturally from seed rather than from sprouts?

  1. The number of retained snags
  2. The depth of the litter layer alone
  3. The presence of a nearby seed source and receptive seedbed Correct answer.
  4. The slope aspect of the opening

Explanation

Natural seeding requires a viable seed source plus a seedbed where seeds can germinate and seedlings survive. Snags, litter depth, and aspect influence microsite conditions but cannot substitute for the absence of seed. Where sprouting species dominate, vegetative regeneration may prevail instead.

Question 19Forest Ecology and Silviculture

Which of the following best characterizes an uneven-aged stand?

  1. A stand with no trees in the sapling size class
  2. Trees of a single age class with a closed canopy
  3. At least three age classes mixed in the same stand Correct answer.
  4. A stand regenerated only by clearcutting

Explanation

Uneven-aged stands contain three or more age classes intermingled, typically maintained through selection cutting. A single age class describes an even-aged stand. Uneven-aged structure is incompatible with clearcut-only regeneration.

Question 20Forest Ecology and Silviculture

Which practice most directly reduces the risk of a bark beetle outbreak spreading through a dense, stressed conifer stand?

  1. Increasing rotation length to grow larger trees
  2. Reducing stand density through thinning to improve vigor Correct answer.
  3. Eliminating all dead wood from the site
  4. Retaining all large-diameter trees as legacy

Explanation

Thinning reduces competition and water stress, improving tree vigor and lowering susceptibility to bark beetles. Longer rotations and retained large trees can increase susceptibility by providing more host material. Dead wood removal has limited effect on outbreak dynamics.

Question 21Forest Ecology and Silviculture

In a stand table, the number of trees per hectare in successive diameter classes is called what?

  1. Stocking guide
  2. Size-class distribution Correct answer.
  3. Yield table
  4. Site index curve

Explanation

The size-class distribution, often shown as a diameter distribution, gives tree counts by diameter class. Site index curves describe height growth, stocking guides relate density to basal area, and yield tables predict volume over time. Each serves a different planning purpose.

Question 22Forest Ecology and Silviculture

A manager wants to compare the density of two stands of different species and ages. Which approach is most defensible?

  1. Compare mean diameter of the largest trees
  2. Compare total tree counts per hectare
  3. Compare stand density index relative to each species' reference Correct answer.
  4. Compare raw basal area values directly

Explanation

Stand density index expresses density relative to a species-specific reference, allowing valid comparison across species and ages. Raw basal area and tree counts are confounded by differences in species and size structure. Diameter of the largest trees describes structure, not density.

Question 23Forest Ecology and Silviculture

Which combination best describes a two-aged shelterwood regeneration method?

  1. Single-tree selection repeated every ten years
  2. Seed cut followed by final removal once regeneration is established Correct answer.
  3. Diameter-limit cutting removing all trees above a threshold
  4. Clearcut followed by planting of the same species

Explanation

A shelterwood sequence uses a seed cut to establish regeneration under partial shade, then a final removal cut to release it, producing two age classes. Clearcutting gives one age class, and selection or diameter-limit cutting produce different structures. The seed-cut to removal-cut sequence is the defining feature.

Question 24Forest Ecology and Silviculture

A forest manager observes increasing dominance of shade-tolerant species in the understory of a partially cut stand. What is the most likely silvicultural consequence if no action is taken?

  1. The stand will shift toward tolerant species and lose the desired intolerant component Correct answer.
  2. Site index will rise for the intolerant species
  3. The stand will develop a pure even-aged structure
  4. Regeneration of the intolerant species will improve

Explanation

Partial cutting that leaves moderate shade favors tolerant regeneration, so the future canopy shifts toward tolerant species while intolerant species decline. Site index is a site property and does not change with composition. Intolerant regeneration generally suffers under such shade.

Question 25Forest Ecology and Silviculture

Which factor most limits the use of single-tree selection in a forest dominated by a shade-intolerant species?

  1. Excessive soil disturbance from skidding
  2. Too few large trees for seed production
  3. Insufficient light reaching the forest floor for regeneration Correct answer.
  4. Overly rapid canopy closure after cutting

Explanation

Single-tree selection removes scattered trees and leaves a largely closed canopy, so light at the floor is too low for intolerant regeneration to establish and grow. Skidding disturbance and canopy closure are secondary concerns. Seed supply is usually adequate where mature trees remain.

Question 26Forest Ecology and Silviculture

Which site characteristic most directly determines the natural regeneration method chosen after a regeneration cut in a boreal conifer stand?

  1. Total volume removed in the previous commercial thinning
  2. Average diameter of the harvested overstory trees
  3. Depth and moisture regime of the forest floor seedbed Correct answer.
  4. Distance to the nearest all-weather logging road

Explanation

Natural regeneration success depends first on whether seed can reach and germinate on a suitable seedbed. Forest floor depth, humus type, and moisture regime control germination and early seedling survival far more than road access or past thinning volume. The harvested diameter and removed volume describe the stand, not the regeneration environment.

Question 27Forest Ecology and Silviculture

A stand is thinned and the residual trees show increased diameter growth within a few years. Which mechanism best explains this response?

  1. Greater allocation of carbon to root growth instead of stem growth
  2. Reduced competition for light, water, and nutrients among the residual trees Correct answer.
  3. Increased soil nitrogen fixation by the residual trees
  4. A shift in the stand toward more shade-tolerant species

Explanation

Thinning removes competitors and leaves more site resources per residual stem. The released trees capture additional light, water, and nutrients and allocate them to cambial growth, producing wider annual rings. Nitrogen fixation and species shifts are not direct causes of the immediate diameter response.

Question 28Forest Ecology and Silviculture

Which measure is the most direct expression of stand density independent of species and age?

  1. Standing volume per hectare
  2. Basal area per hectare
  3. Stand density index Correct answer.
  4. Mean height of dominants

Explanation

Stand density index converts trees per hectare and quadratic mean diameter to a common reference, so stands of different species and ages can be compared on one scale. Basal area and volume are absolute quantities that vary with size and species. Mean dominant height describes site productivity, not density.

Question 29Forest Ecology and Silviculture

A manager applies a selection system in a stand where the target species is intermediate in shade tolerance. Which design element is most critical to sustaining that species?

  1. Setting a maximum diameter limit that removes the largest trees each entry
  2. Lengthening the cutting cycle to several decades beyond the species' rotation
  3. Removing all mature trees in a single cut across the whole stand
  4. Maintaining a residual basal area and canopy structure that keeps advance regeneration viable Correct answer.

Explanation

Selection systems depend on advance regeneration surviving between entries, so residual canopy and basal area must let the target species persist without being suppressed. A diameter-limit cut tends to high-grade the stand and degrade genetic quality. Clearcutting and very long cycles contradict the selection concept.

Question 30Forest Ecology and Silviculture

Two stands have the same site index for a species, but one carries far more stems per hectare. Which interpretation is most defensible?

  1. The denser stand is more fully occupied and may be at greater risk of stagnation Correct answer.
  2. Site index cannot be compared between stands with different densities
  3. The sparser stand will always yield more total volume at rotation
  4. The denser stand has higher site productivity

Explanation

Site index measures height growth of dominant trees and is largely independent of density within normal stocking. A stand with many more stems is more fully occupied and can stagnate if density exceeds the threshold where growth is redistributed rather than added. Higher stem counts do not raise site quality.

Question 31Forest Ecology and Silviculture

Which soil process most directly governs the availability of nitrogen to trees in an upland forest?

  1. Mineralization of organic nitrogen by soil microbes Correct answer.
  2. Weathering of primary silicate minerals
  3. Leaching of dissolved organic carbon into groundwater
  4. Cation exchange of calcium on clay surfaces

Explanation

Most forest nitrogen is bound in organic matter and must be mineralized to ammonium before plants can take it up. Microbial decomposition therefore controls nitrogen supply in upland soils. Silicate weathering and calcium exchange concern base cations, and carbon leaching removes carbon rather than supplying nitrogen.

Question 32Forest Ecology and Silviculture

A stand regenerated after a severe fire is dominated for decades by a fast-growing, light-seeded species, while a slower, shade-tolerant species establishes beneath it. Which concept best explains this pattern?

  1. Site degradation caused by nutrient loss during the fire
  2. Stand stagnation caused by excessive stocking
  3. Genetic drift within the regenerating population
  4. Successional replacement driven by changing light conditions Correct answer.

Explanation

The pioneer species captures the site after disturbance, but its own canopy shades out its regeneration while favoring tolerant species that establish below. Over time the tolerant species ascends and replaces the pioneer, which is the classic pathway of successional replacement. Stocking, nutrient loss, and genetic drift do not explain the directional species change.

Question 33Forest Ecology and Silviculture

In a mixed hardwood stand, a forester wants to favor a mid-tolerant species that is currently in the codominant crown class. Which marking approach is most appropriate?

  1. Remove all trees of the target species to allow natural seeding
  2. Remove the largest trees of the target species to release smaller stems
  3. Remove codominant and dominant competitors from the immediate neighborhood of the crop trees Correct answer.
  4. Remove only suppressed trees from the lower crown classes throughout the stand

Explanation

Crop-tree release removes competitors whose crowns interfere with the selected stems, including codominants and dominants, not just suppressed trees. Cutting only suppressed trees leaves the main competitors in place. Removing the largest target trees or all target trees works against the desired species.

Question 34Forest Ecology and Silviculture

A manager plans a group selection harvest in a stand with a seed source that is unreliable in heavy mast years. Which adaptation is most defensible?

  1. Shorten the cutting cycle so that openings are harvested before seed fall
  2. Convert the stand to a clearcut system to guarantee uniform regeneration
  3. Reduce opening size and plan for planting or advance regeneration to supplement natural seeding Correct answer.
  4. Enlarge openings to reduce edge shading and rely on wind-dispersed seed

Explanation

When seed supply is unreliable, smaller openings retain more shade and edge influence but cannot guarantee regeneration, so planting or reliance on existing advance regeneration becomes necessary. Enlarging openings does not fix a seed shortage. Clearcutting worsens the problem, and shortening the cycle does not create seed.

Question 35Forest Ecology and Silviculture

Which factor most strongly limits the use of single-tree selection in a stand dominated by a species with low shade tolerance?

  1. Loss of soil nutrients from repeated entries
  2. Inability of the species to regenerate and survive under a partial canopy Correct answer.
  3. Reduced markets for small-diameter products
  4. Excessive windthrow risk on the residual trees

Explanation

Single-tree selection maintains a continuous partial canopy, and a shade-intolerant species cannot establish or persist as advance regeneration beneath it. Windthrow, nutrient loss, and small-diameter markets can be concerns, but they do not fundamentally exclude the method the way shade tolerance does.

Question 36Forest Ecology and Silviculture

In a forest inventory, which sampling design is most appropriate for estimating volume in a stand with highly variable tree sizes and clustered mortality gaps?

  1. A single large plot covering the entire stand
  2. Variable-radius plots centered on a systematic grid Correct answer.
  3. Strip lines placed only along the stand boundary
  4. Fixed-radius plots placed on a regular grid

Explanation

Variable-radius plots sample trees with probability proportional to basal area, which captures a wide range of tree sizes efficiently and can be distributed systematically to represent the whole stand. A single plot cannot represent variability, and boundary strips bias the sample toward edge conditions.

Question 37Forest Mensuration and Inventory

In forest mensuration, what does DBH conventionally refer to when measured on a standing tree?

  1. Diameter of the stump at ground level
  2. Diameter at the midpoint of the merchantable bole
  3. Diameter of the crown spread measured at the widest point
  4. Diameter of the stem measured outside bark at 1.3 m above ground level Correct answer.

Explanation

DBH is the standard reference diameter taken at breast height, conventionally 1.3 m above ground on the uphill side of the tree. It is measured outside bark unless the inventory protocol specifies diameter inside bark. Consistency of height and side of measurement is essential for comparability across plots and inventories.

Question 38Forest Mensuration and Inventory

A cruiser records diameters with a diameter tape on a slope. Which practice gives the correct stem diameter?

  1. Read the tape where it crosses the downhill side of the stem
  2. Add the slope correction factor to the tape reading
  3. Hold the tape perpendicular to the stem axis rather than horizontal to the ground Correct answer.
  4. Pull the tape tight enough to compress the bark slightly

Explanation

A diameter tape is graduated so that a circumference reading converts directly to diameter, and this conversion assumes the tape encircles a cross-section perpendicular to the stem axis. On sloping ground the stem is usually near vertical, so the tape must be held perpendicular to the axis, not parallel to the slope. Holding it in the plane of the ground would overestimate diameter on steep terrain.

Question 39Forest Mensuration and Inventory

Basal area per hectare of a stand is most directly obtained by multiplying which quantity by the number of trees per hectare?

  1. The mean tree height
  2. The mean merchantable volume
  3. The mean tree basal area Correct answer.
  4. The mean crown radius

Explanation

Stand basal area is the sum of individual tree cross-sectional areas at breast height, so multiplying mean tree basal area by trees per hectare yields stand basal area per hectare. Height, crown radius, and volume do not have area units and cannot substitute. This relationship underlies point-sampling expansions as well.

Question 40Forest Mensuration and Inventory

Which instrument is designed specifically to measure tree height by sighting the top and base of the tree?

  1. A diameter tape
  2. A clinometer Correct answer.
  3. A bark gauge
  4. A wedge prism

Explanation

A clinometer measures vertical angles, which combined with horizontal distance to the tree give height by trigonometry. Wedge prisms are used for basal-area sampling, bark gauges for bark thickness, and diameter tapes for circumference-based diameter. Height measurement therefore depends on angle and distance, not on stem contact.

Question 41Forest Mensuration and Inventory

On a fixed-area plot of 0.05 hectare, 12 trees are tallied. What is the estimated trees per hectare?

  1. 600
  2. 60
  3. 240 Correct answer.
  4. 24

Explanation

Trees per hectare equals the tally divided by plot area in hectares, so 12 divided by 0.05 gives 240 trees per hectare. Plot expansion factors are simply the reciprocal of plot size in hectares. Using the reciprocal of 0.05, which is 20, and multiplying by 12 confirms the result.

Question 42Forest Mensuration and Inventory

What does a wedge prism used in variable-radius sampling estimate directly?

  1. Volume per hectare
  2. Basal area per hectare Correct answer.
  3. Mean diameter
  4. Trees per hectare

Explanation

In angle-count sampling the prism admits or rejects trees according to a fixed angle, and each tallied tree represents a constant amount of basal area per hectare determined by the basal area factor. Trees per hectare and volume require additional measurements or conversions. Mean diameter likewise must be computed from the tallied trees.

Question 43Forest Mensuration and Inventory

When a log's small-end diameter is measured for volume estimation, why is the measurement usually taken inside bark?

  1. Because the volume tables are based on wood volume rather than bark volume Correct answer.
  2. Because bark thickness is assumed to be zero on all logs
  3. Because inside-bark diameters are always larger than outside-bark diameters
  4. Because bark is removed before the log is scaled

Explanation

Log volume tables and scaling rules commonly express wood volume, so diameters are taken inside bark to exclude the bark shell. Bark thickness varies by species and season, so outside-bark diameters would introduce inconsistent bias. The measurement is a convention of the scaling system, not a physical removal of bark.

Question 44Forest Mensuration and Inventory

A sample of 25 trees has a mean DBH of 30 cm with a standard deviation of 6 cm. What is the standard error of the mean?

  1. 30 cm
  2. 1.2 cm Correct answer.
  3. 0.24 cm
  4. 6.0 cm

Explanation

The standard error of the mean is the standard deviation divided by the square root of the sample size. Here 6 divided by the square root of 25, which is 5, gives 1.2 cm. The standard error shrinks as sample size grows, which is the basis for sampling intensity decisions.

Question 45Forest Mensuration and Inventory

In a cruise where every possible fixed-area plot of a specified size within the stand has an equal chance of selection, the design is best described as which type?

  1. Simple random sampling Correct answer.
  2. Systematic sampling with a random start
  3. Angle-count sampling
  4. Stratified double sampling

Explanation

Simple random sampling gives every possible sample unit an equal and independent chance of selection, which matches the described design. Angle-count sampling selects trees by a size-angle criterion rather than plots. Systematic sampling with a random start selects plots on a regular grid, and double sampling uses two measurement intensities.

Question 46Forest Mensuration and Inventory

A stand covers 40 hectares and has a mean basal area per hectare of 24 m². What is total stand basal area?

  1. 1,920 m²
  2. 96 m²
  3. 960 m² Correct answer.
  4. 480 m²

Explanation

Total basal area is the per-hectare value multiplied by the number of hectares, so 24 times 40 equals 960 m². Keeping units consistent avoids the common error of dividing instead of multiplying. Stand-level totals of this kind feed directly into volume and biomass expansions.

Question 47Forest Mensuration and Inventory

A tree's total height is measured as 24 m with a clinometer set at a horizontal distance of 20 m from the tree, and the base of the tree is level with the observer. Which trigonometric relation gives the height?

  1. Height equals the horizontal distance multiplied by the slope distance
  2. Height equals the horizontal distance multiplied by the tangent of the elevation angle to the top Correct answer.
  3. Height equals the horizontal distance divided by the sine of the elevation angle
  4. Height equals the horizontal distance multiplied by the cosine of the elevation angle

Explanation

With the base at the observer's eye level, the tree top, the observer, and the base point form a right triangle whose opposite side is tree height and adjacent side is horizontal distance. The tangent of the elevation angle equals opposite over adjacent, so height is distance times tangent. Sine and cosine relate other side combinations and do not apply directly here.

Question 48Forest Mensuration and Inventory

A tree has a DBH of 40 cm. Using a basal area factor of 2, how many tally trees per hectare does this single tree represent in an angle-count sample?

  1. About 2
  2. About 8
  3. About 4 Correct answer.
  4. About 16

Explanation

In angle-count sampling each tally tree represents the basal area factor divided by the tree's basal area in square metres. A 40 cm DBH tree has a basal area of about 0.1257 m², and 2 divided by 0.1257 gives roughly 16 trees per hectare, so a single tree of this size represents about 16 trees per hectare. Larger trees represent fewer trees per hectare because each accounts for more basal area.

Question 49Forest Mensuration and Inventory

Which statement best explains why volume tables are species-specific rather than universal?

  1. Diameter tapes are graduated differently for each species
  2. Height measurement accuracy varies by species
  3. Taper and form differ among species, so the same diameter and height yield different volumes Correct answer.
  4. Bark thickness is identical across species but volume tables ignore it

Explanation

Volume depends on stem form and taper as well as diameter and height, and these form characteristics differ systematically among species and sites. A table built for one species will misestimate volume for another even at identical DBH and height. This is why local or regional volume equations are preferred over generic tables.

Question 50Forest Mensuration and Inventory

A 0.1 hectare plot contains 8 trees of species A and 4 trees of species B. What is the estimated trees per hectare for species A?

  1. 8
  2. 40
  3. 12
  4. 80 Correct answer.

Explanation

The expansion factor for a 0.1 hectare plot is 10, so 8 trees of species A become 80 trees per hectare. Species B would expand to 40 trees per hectare. Reporting by species requires applying the same expansion factor to each tally separately.