| Score and class | Definition | Remark |
|---|---|---|
| Class 1: Exploratory phase | Apical shoots and upper side buds form long shoots | Flat, longitudinal expansive shoot development |
| Class 2: Intermediary | Intermediary between class 1 and class 3 | |
| Class 3: Degeneration phase | Only apical bud forms a long shoot. Shoots of side buds are stunted. | Spear-shaped development of main shoots and reduced side shoot formation |
| Class 4: Intermediary | Intermediary between class 3 and 5 | |
| Class 5: Stagnation phase | Stunted long shoots | Claw-like appearance because of pluriannual short shoot chains |
| Class 6: Intermediary | Intermediary between class 5 and class 7 | |
| Class 7: Resignation phase | Die-back of twigs of the topmost part of the crown or even the whole crown itself | |
| Class 8: Regeneration phase | Phase with obvious regeneration | From worse phase to a better form on the same branch |
| Source: International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests, 2010). | ||
Download an Excel workbook containing tree assessment tables found in the stormwater manual.