I was reading someones post in the faerie tales group about how the trees help a form of fairy in England and I came to realize how consistent this idea was throughout Europe. Water fairies such as the nymphs of Greece or the Vila of Slavic lands and the Rusalka of Russia lived where groves of trees grew by rivers. There's a strong relationship between the two types of fairies that often combines them to make them one and the same. Further, earth spirits when angered might become the spirit of the water so they could cause a region to flood.I find it interesting because while it seems like we often divide the elements and the fairies of the elements into very differing types which war with each other it seems more as though many peoples believed that they were the same thing in different forms. In Russia fairy tales indicate a belief that Water and Earth were allied as were Air and Fire and the only real contrast between earth or water and fire.