Bachelor of Forestry Forest Mensuration Flashcards

Which formula is used to calculate the volume of a tree using the Smalian's method?

Answer: V = L × (Ab + At) / 2

Smalian's method calculates log volume as the average of the basal areas of both ends multiplied by the log length.

The Prismatic compass is primarily used in forest mensuration for:

Answer: Running compass traverses and measuring bearing angles

A prismatic compass is used to measure magnetic bearings during traverse surveys in forest areas.

What does 'form quotient' represent in tree measurement?

Answer: Ratio of diameter at mid-height to DBH

Form quotient is the ratio of the diameter at mid-height (or upper stem) to the diameter at breast height, indicating stem taper.

A timber cruise using systematic sampling with a fixed-area plot requires the cruiser to:

Answer: Measure trees within randomly located circular or rectangular plots

Fixed-area plot cruising involves establishing sample plots at systematic intervals and measuring all trees within each plot.

The ocular estimate of crown closure in a stand is typically expressed as:

Answer: Percentage of ground covered by tree crowns

Crown closure (or canopy cover) is expressed as the percentage of the ground area covered by vertical projection of tree crowns.

In log scaling, what is the purpose of deducting for defects?

Answer: To adjust volume estimates to reflect only sound, usable wood

Defect deductions reduce the gross scale to a net scale that reflects only the merchantable, sound wood in the log.

Which instrument measures tree height using the principle of trigonometry based on horizontal distance and vertical angles?

Answer: Hypsometer

A hypsometer uses trigonometric relationships between the observer's horizontal distance and measured vertical angles to calculate tree height.