Erik Heyman, University of Gothenburg (IMAGE) University of Gothenburg Caption Erik Heyman's studies are based on large-scale field experiments in five deciduous forest areas close to three mid-size cities in southwestern Sweden Credit University of Gothenburg Usage Restrictions None 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.