Equation (IMAGE) Stanford University Caption The researchers' equation representing "payments" from plants to microbes, where α (alpha) is the ratio of carbon the plant allocates to two microbes and β (beta) is the ratio of benefits that the plant receives from those microbes. Credit Courtesy of the Peay Lab/Brian Steidinger Usage Restrictions Image may only be used with appropriate caption or credit 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.