| Summary: | The objective of this work was to determine the applicability of the dry-weight-rank (DWR) method for evaluating the botanical composition of forest understorey vegetation. An analysis of plant species abundance was carried out, and instead of ranking the three most abundant species, as is commonly used, up to twelve ranks were scored. Concurrently, four models of relative abundance distribution (RAD) of species were compared for their ability to explain the abundance of species in the study area. The Power-fraction model resulted in the best goodness-of-fit and it was subsequently used to produce the coefficients for the DWR method. Lin's concordance correlation coefficient, the adjusted coefficient of determination, the residual standard deviation and Spearman's rank-order correlation coefficient indicated a good performance of the DWR method. Biomass data and the Shannon index for diversity were also considered. Further analyses showed that there was a trade-off between the number of ranks scored and the accuracy of the botanical composition produced by the DWR method. It is concluded that, so long as the RAD model that explains the distribution of plant species is known, the DWR method can be applied to forest understorey vegetation.
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