This looks awesome! How did you do that? (If I may ask). I'm also impressed by the 6 bark pictures. Maybe because i doen't recognise the species. (I'm studying forestry here in The Netherlands). If you like you could have a look at my photo's at [link] (I use dA mostly for emotes)
Explosion was created with a standard garden hose and adapter and an unused aquarium. I sprayed a jet of water (from the hose) into a partially filled aquarium and took the shot point up towards the surface. This shot has actually been rotated 180 degrees (so it is upside down). I then tweaked the exposure in Photoshop. I cant remember exactly what I did, though. I think I played around with white balance some.
Regarding the trees, they are redwoods from California. I'm no tree geek, so I can't tell you any further than that!