More information can be found here.
One of my favourite pieces from last year is called
V = B0 + B1 *D^ B2 + B3 *D^ B4 *H^ B5 by Neville Gabie.
From the program: The title of the work is the mathematical equation used by foresters to calculate the total cubic volume of wood in a tree by measuring its girth and height while it is still standing. Using this formula, science and conservation staff of the Royal Botanical Gardens calculated the total volume of this red oak (killed by gypsy moths) before it was cut down. The resulting work is the entire tree, from the largest sections of the trunk to the smallest branches, cut into cubes and packed as a solid block in its original location.