There's a funny story with this artwork, when I first published the design on the internet in 2008, I got hit with a copyright violation and my image was removed from the site I had published it on. Apparently, another artist (NOT the aforementioned, Davis) had flagged it because they thought it looked very similar to their own design. I won't point it put or mention the artist's name. But if you had done an image search for "Celtic Tree of Life" back in 2008 only a handful of designs came up. The first and most prominent would have been the design I just mentioned, and mine (the one shown above) would have appeared at the end of the search results. 

I spent a good 6 months in communication with the site I was publishing on at the time proving that my work was my own. I even submitted photos of the original design sketches on college lined notebook paper. Eventually they were convinced and my design was allowed back into publication and reproduction. 

I am pleased to say that now if you repeat that image search you will be rewarded with hundreds of beautiful designs and variations on the theme and I think that is beautiful.