What makes a tree important? Is it the ability to withstand storms, wars and human greed through the centuries? The people that rest in its shade, the lovers who carve their names, the playing children creating eternal memories? Or is it just what country it grows in? The organizers of the European Tree of the Year contest, a relatively niche event on the Brussels social calendar, have been grappling with these questions for years. The competition, which started in 2002 as a national event in