Efficient Discrimination of Some Moss Species by Fourier Transform Infrared Spectroscopy and Chemometrics

Fourier-transform infrared (FT-IR) spectroscopy with the attenuated total reflectance (ATR) technique was used to classify 14 samples (11 species) from three moss families (Mielichhoferiaceae, Bryaceae, and Mniaceae). The FT-IR spectra ranging from 4000 cm−1 to 650 cm−1 of the 14 samples were obtained. To group the spectra according to their spectral similarity in a dendrogram, cluster analysis and principal component analysis (PCA) were performed. Cluster analysis combined with PCA was used to give a rough result of classification among the moss samples. However, some species belonging to the same genus exhibited very similar chemical components and similar FT-IR spectra. Discrete wavelet transform (DWT) was used to enhance the differences among species with similar chemical components and FT-IR spectra. Three scales were selected as the feature-extracting space in the DWT domain. Results showed that FT-IR spectroscopy combined with chemometrics was suitable for a systematic research classification of bryophytes.