FM Forest Measurements & Inventory Flashcards
6 cards from real FM practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 FM Forest Measurements & Inventory flashcards as text
The 'International 1/4-inch log rule' is used in timber cruising to:
Answer: Estimate the board-foot volume of logs based on small-end diameter and log length
The International 1/4-inch rule is a widely used log scale that estimates the recoverable board-foot lumber volume from a log based on its small-end diameter inside bark and length.
In forest inventory, 'cruise intensity' refers to:
Answer: The proportion of the total forest area sampled, expressed as a percentage
Cruise intensity is the percentage of the total timber sale or stand area that is sampled, with higher intensities providing more accurate volume estimates but requiring greater field effort.
What does 'merchantable height' mean when measuring trees for a timber sale?
Answer: The height of the usable portion of the tree stem that meets minimum size requirements for products
Merchantable height is measured from the stump to the point where the stem diameter falls below a minimum utilization standard or has significant defect, defining the recoverable portion of the tree.
A 'Biltmore stick' is a field tool used to:
Answer: Estimate tree diameter by holding the stick at arm's length against the tree
A Biltmore stick is a graduated scale held at a fixed arm's length (25 inches from the eye) to estimate tree DBH through parallax, providing a quick but approximate diameter estimate.
What is 'periodic annual increment' (PAI) in forest growth measurement?
Answer: The average annual volume increase over a specified measurement period
PAI is the average annual volume, basal area, or height growth calculated by dividing total growth over a measurement period (e.g., 10 years) by the number of years in that period.
In forest inventory, 'gross volume' differs from 'net volume' in that:
Answer: Gross volume includes all wood, while net volume deducts defects, cull, and waste
Gross volume is the total wood volume in a tree or stand without deductions; net volume subtracts estimated losses from cull, rot, sweep, crook, and other defects to give the actually usable volume.