Table 6 Definition of five ratios contrasting tree species diversity in the regeneration and overstory layers
From: Tree regeneration characteristics in limestone forests of the Cat Ba National Park, Vietnam
| Ratio | Function | Explanation |
|---|---|---|
| Species richness ratio (SRR) | Nr/ No |
Nr, number of species in the regeneration layer per sample plot No, number of species in the overstory layer in the same sample plot |
| True diversity ratio (TDR) | Tr/To |
Tr, true diversity of the regeneration layer per sample plot To, true diversity of the overstory layer in the same sample plot |
| Same species ratio (SSR) | Sr/No |
Sr, number of regeneration species present in the overstory layer per sample plot No, see above |
| Newly occurred species ratio (NSR) | Nn/No |
Nn, number of species occurring in the regeneration layer but not in the overstory layer of a sample plot No, see above |
| Threatened species ratio (TSR) | Rr/Ro |
Rr, number of threatened tree species in the regeneration layer per sample plot Ro, number of threatened tree species in the overstory layer in the same sample plot |