BSC research has been a hot topic in the past two decades however, the intimate interactions and arrangements between cyanobacteria, green algae, lichens and mosses within the soil itself has never before been visualised. To remedy this, we used a confocal laser scanning microscope (CLSM) which utilises laser light of specific wavelengths to visualise the active photosynthetic organisms like cyanobacteria. We viewed the BSCs from the soil surface, down to the deeper layers without destroying or disturbing the structure. When BSC organisms are dead, they can’t be visualised by CLSM. Despite this, the dead organic matter and glue excreted by the cells remains in the soil for a long time and are both important BSC features, aiding with continued soil stabilisation. After the microscopy stage, the information was processed with image analysis software. This software calculated the volume of carbon stored as biomass in the cyanobacteria and green algae at a specific soil depth. This analysis led to the creation of new terminology illustrated in Figure 3: a photosynthetic active layer (PAL) made of active organisms, and a photosynthetic inactive layer (PIL). The latter consists of the cell and glue remnants which stick to the soil particles and bind the BSC together. The thickness of the distinct layers is the result of complex interactions such as water availability, disturbance regime, soil texture and the developmental stage of a BSC. We created this technique at
TU Kaiserslautern and could be applied to future studies, greatly enhancing comparisons of different BSCs.