This is a rowan or mountain ash, Sorbus acuparia. They grow wild in the Alps and climb pretty high up the hills. Anyway, a rowan of this caliper is very rare. I do not know of another one. Many folks tried to talk me into selling it.
The first images are as of one year ago. The final ones are the tree as of this morning. It is in the naturalistic style, in the informal broom form, suposed to look like a real tree and not like a bonsai.