A cross-section of biocrust (IMAGE) Penn State Caption A cross-section of biocrust taken by confocal scanning laser microscopy. Soil particles are visible as various shades of gray, while the bundles of cyanobacterial filaments (fluorescent red) are situated between them. Credit Penn State Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.