Critical Root Zone
/KRIT-ih-kul root zohn/🌲 Arboriculture●● Intermediate
Also known as: CRZ, root protection zone
The critical root zone (CRZ) represents the minimum root area that must remain undisturbed for a tree to maintain structural stability and adequate health. It is generally defined as a circular area with a radius of 1 to 1.5 feet per inch of trunk DBH. Severing roots within the CRZ can cause immediate structural instability, while compaction or grade changes can lead to gradual decline.
Etymology
From Greek kritikos (able to discern) + Old Norse rōt (root) + Greek zōnē (belt)
Example
“Root cutting within the critical root zone of the mature maple led to progressive crown dieback over three years.”