REFLECTANCE SPECTROPHOTOMETRY OF CYANOBACTERIA WITHIN SOIL CRUSTS - ADIAGNOSTIC-TOOL

Identification of cyanobacterial soil crusts is important for mapping apparently barren soils. The letter presents a diagnostic tool for the identification of cyanophyte within soil crusts by means of in vivo r eflectance spectrophotometry measurements. Spectral reflectance spectr a of the crust samples were measured under several conditions-dry, aft er wetting, after their phycobilin pigments had been removed, and afte r the crust had been immersed in paraffin oil. Differences in the refl ectance were enhanced by calculating ratio spectra. It is shown in thi s letter that relative higher reflectivity of the crust in the blue re gion is caused by the spectral characteristics of the phycobilins. Thi s work is a first step towards mapping biogenic crusts by using airbor ne or spaceborne sensors which have the capability to detect in the bl ue band.