Table 1 Parameters used to calculate the index of vulnerability (IV)
Parameters | 1 (Low scale) | 2 (Average scale) | 3 (Strong scale) |
|---|---|---|---|
Use frequency (N1) | N1 < 20% | 20% ≤ N1 < 60% | N1 ≥ 60% |
Number of uses (N2) | N2 < 2 | 2 ≤ N2 ≤ 4 | N2 ≥ 5 |
Plant parts used (N3) | Leaves, latex | Fruit, branches | Wood, seeds, bark, root, flower |
Number of plant parts (N4) | N4 = 1 | N4 = 2 | N4 ≥ 3 |
Collection mode (N5) | Collection on the ground | Collection on the tree, cutting | |
Development stage (N6) | Old, senescent | Adult | Young |
Relative frequency (N7) | Fr ≥ 2/3 Fm | 1/3 Fm ≤ Fr < 2/3 Fm | Fr < 1/3 Fm |