Live Crown Ratio
/liv kroun RAY-shee-oh/🌲 Arboriculture●● Intermediate
Also known as: LCR, crown ratio
Live crown ratio (LCR) is a key indicator of tree health and vigor, calculated by dividing the length of the live crown by the total tree height. A healthy deciduous tree typically has an LCR of 50-70%, while conifers may maintain 60-80%. Low LCR indicates stress, poor growing conditions, or excessive competition. It is a critical factor in tree risk assessment and pruning decisions.
Etymology
From Old English līf (life) + Latin corona (crown, wreath) + Latin ratio (reckoning)
Example
“The oak's live crown ratio had dropped below 30%, indicating it needed more growing space.”