Genera (IMAGE) National Institute for Environmental Studies Caption Number of genera that respond negatively and positively to the impacts of ironwork. Results for two historical periods, early modern (446-151 BP) and Kofun (c. 1700-1300 BP), are shown Credit NIES Usage Restrictions Credit required. 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.