Different Fern Species (IMAGE) University of Turku Caption Different fern species require different kinds of soil to grow, so their presence can be used to deduce site conditions. Credit Gabriela Zuquim Usage Restrictions The media may use the enclosed photos freely in connection with news on the topic. The photographers must always be credited. 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.