Thanks, for this and the other warning. I reported him. I already found several of my images being sold by the same guy in other sites (Pinterest, Flickr, ...). I contacted him by mail too but no reaction.
Thanks! Originally those are oak trees, from a collection I acquired a long time ago. I'm sorry but I don't remember where I got them but it was probably in C3D or in Renderosity. I put all my trees in one folder and therefore I lose track of their exact origins, all that remains is the name. But anyway, I edited the trees in the plant editor, changed their shapes a bit and all materials completely so you won't find them anywhere exactly like this.
Wow, I love how the light beams fall through the trees. Also the trees look really nice, and so is the vegetation underneath them. I also think that the pov is nicely chosen, so we get to see some nice reflections in the water.