Soil microbial seasonality (IMAGE) San Diego State University Caption San Diego State University ecologists found that seasonal fluctuations in temperature lead to a corresponding fluctuation in soil microbial populations, and increased carbon emissions. Credit SDSU Usage Restrictions credit Xiaofeng Xu's research team at SDSU 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.