Colorimetry vs. spectrophotometry: which is better for discrimination of 13 native tree species in Southern Brazil?

The application of colorimetric parameters for wood quality control, species discrimination, and property evaluation has been described, but no studies have been published comparing the results obtained by colorimetry and spectrophotometry for the analysis of wood. The objective of this study was to establish spectral parameters for 13 native species from an Araucaria forest stand in Southern Brazil using colorimetric and spectrophotometric methods, and to compare the two methods for species discrimination. For each species, three individuals were collected, from which a disc was removed at breast height and divided into six specimens from pith to bark for analysis. Four parameters were determined for each specimen, two on the transversal surface and two on the radial surface, by each method. The results revealed a variation in the parameters L*, a*, and b*, and PCA results varied with the surface and species evaluated. Measurements of the radial surface, in general, yielded a lower species differentiation using the two methods. When considering the potential use of a technique for species identification in the field, it is necessary to rely on prior data obtained using the same method. In conclusion, colorimetry proved to rapidly discriminate native species in Araucaria forest areas.