Most plants are custom species made with the plant editor. I made the terrain with GeoControl 2 Clouds are from White Magic by Dick Scherzinger Atmosphere by www.ddcreations.eu
I got the tree from Cornucopia3d.com . I only used 1 light, the sun, I never use more than 1 light. In the natural world , outside in nature, you also just have the sun. Combined with Global Radiosity you get the best results.
They already have ones on Cornucopia3D [link] I haven't bought them yet. But I don't think creating such a tree in the plant editor is possible with any of the other existing ones. They don't really have the subsets for it