Old Black Pine Tree in Anatolia, Turkey (IMAGE) University of Arizona Caption By studying the annual rings of centuries-old black pines (Pinus nigra) such as this, scientists figured out that the northern boundary of the tropics moved back and forth in the last 800 years. Credit Ünal Akkemik Usage Restrictions The photo <Black pine in Anatolia, Turkey> may only be used to illustrate a story about the research described in the accompanying news release, 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.