Crown ratio [Live crown ratio, Crown length ratio]
n. The ratio of crown length to total tree height (Helms 1998).
Crown ratio (along with its synonyms live crown ratio and crown length ratio) is a silvicultural measurement indicating tree vigor. Crown ratio is sometimes used to estimate crown base height when only tree height and crown ratio are known. Some silvicultural forest inventories that focus on tree growth measure compacted crown ratio. In those cases, it may be necessary to uncompact that estimate in order to estimate what is known as the uncompacted crown ratio.