FT-RAMAN SPECTROSCOPY OF DIRINA-MASSILIENSIS F SOREDIATA ENCRUSTATIONS GROWING ON DIVERSE SUBSTRATA

The FT-Raman spectra of encrustations of Dirina massiliensis f. soredi ata on a variety of substrata collected from several locations have be en recorded and analysed. This is the first time that such a comprehen sive spectroscopic study has been made of lichen encrustations of the same species on different substrata. This lichen is able to bring abou t deterioration in all six different lichen substrata studied. Calcium oxalate dihydrate is produced in significant amounts by the reaction of lichen-generated oxalic acid with various calcareous rock substrata , as well as particles of the particular substratum itself. However, f or specimens growing on a non-calcareous substratum in an exposed mari time location only traces of calcium oxalate are produced and more not iceable quartz particles are incorporated into the thalli. The results indicate that this lichen can degrade its substratum highly effective ly and there is evidence of different strategies being exhibited by li chens in different habitats and geographical locations. (C) 1997 The B ritish Lichen Society