USGS Scientist Sasha Reed Studies Biocrust Testing Plot (IMAGE) U.S. Geological Survey Caption USGS scientist Sasha Reed studies sites where different climate conditions are being mimicked to determine effect on biocrusts. Credit Jennifer LaVista, USGS Public domain Usage Restrictions Credit: USGS License Licensed content 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.