Tree rings in a wood sample (IMAGE) University of Utah Caption Detail of a wood core with visible growth rings (more recent rings towards the left) and bark on the right. Credit Antoine Cabon Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.