That's Peter of Pooktre Tree Shapers, who specializes in shaping trees as they grow in pre-determined shapes (sort of like a living sculpture!): Link
Check out more "twisted" trees at Web Urbanist's neat post: 25 Seriously Twisted Trees: From Uncanny Urban Overgrowth to Awesome Arbosculpture - Thanks Bjorn!
Arborsculpture relates to Richard Reames's method of shaping trees.
At Wikipedia there was a consensus that a neutral name was needed for the artform, and Tree shaping was decided upon. http://en.wikipedia.org/wiki/Tree_shaping
You may be also interested in visiting this website http://www.treeshapers.net ,which shows photos from all the different tree shapers from around the world.
http://www.primeau.qc.ca/coexis/ArbresF/1992_2004.html