Tree health indicators used for visual rank assessment (Shibata 2007).
| Indicators | Abbreviation | Rank 1 | Rank 2 | Rank 3 | Rank 4 |
|---|---|---|---|---|---|
| Tree vigor | Tvg | vigorous growth | slight decline in vigor (not conspicuous) | clear decline in vigor | clearly poor growth state and no prospect of recovery |
| Tree form | Tfm | maintenance of the natural tree form | slight loss of the natural tree form (not conspicuous) | conspicuous loss of the natural tree form | complete loss of the natural tree form |
| Branch growth | Bgr | normal (≥ 30 cm at the top) | slightly less than rank 1 | new branches are short and thin | new branches are extremely short |
| Crown dieback | Cdb | no dieback | slight dieback (not conspicuous) | conspicuous dieback or cuttings | severe dieback or cutting |
| Crown density | Crd | closed crown and high density of branches and leaves | slightly less than rank 1 | distinct porosity with sparse branches and leaves | many dead branches, poor leaf development, and very sparse crown |
| Leaf shape and size | Lsh | normal | few deformed or small leaves | deformed leaves or generally small leaves | many deformed leaves or conspicuously small leaves |
| Leaf color | Lcl | normal | few pale leaves or diseased leaves | abnormal (many pale leaves or diseased leaves) | conspicuously abnormal leaves |
| Bark condition | Brk | active thickening growth and active bark regeneration | normal | old bark, no bark regeneration, or damage | very old bark, distinct damage, or decay |