where W is the sum of the minimum of IV between plot A and B for each species. The value of A+ B
represents the sum of D, BA and F; the value is 600 in this study. To compare the percentages of similarity in the forest community between plots, a matrix representing the %S and the percent dissimilarity (%DS = 100 − %S) between the paired plots is shown in Table S6.
To examine the species diversity of woody plants in each plot, we used the Shannon–Wiener Index
(H′ = Σ Pi × ln Pi)41, where Pi is the value of ni (number of individuals in species i)/N (total number of individuals in all species). H′ is a measure of overall biodiversity and maximized when all species have the same number of individuals. This index assumes that individuals are randomly sampled from an infinite population. Simpson’s index43 is computed as λ = Σ Pi
2. Fisher’s index α is defined by S = α ln(1 + N/α)44, where N is the total number of individuals in all species and S is the number of species in each L-quadrat. These parameters are measures used to clarify the diversity of tree species by distance from the boundary lines.
To measure the distribution pattern of all individual trees in each plot, the evenness index of the community (E) was calculated following the method of Hill (1973)45. The values of E represent a coherent system for biodiversity that includes the Shannon-Wiener index and Simpson index as follows: