Figure 2: Analytical framework of the approach. Using individual-based rarefaction curves (A-C) and their conversion to effective numbers of species (ENS) (D-F), diversity change can be dissected into contributions of SAD-effects and N-effects. The columns represent 3 hypothetical scenarios of diversity patterns between a diverse “tropical” and a less diverse “temperate” local community. In first scenario (A, D, G), the difference in diversity results from a passive sampling effect, as the tropical community supports more individuals than the temperate one. In the second scenario (B, E, H), abundance remains constant but the pattern is underlain by differences in the regional species abundance distribution (SAD, i.e. larger species pool in the tropics). In the third scenario (C, F, I), both abundance and the regional SAD vary between the two communities. Using the ENS conversion, the total diversity of each sample is dissected into a SAD component and a N-component (dots in G- I). By examining the difference of the components between the communities, we can quantify the corresponding SAD effects and N effects (pie charts in G-I).