Estimating the volume of woody debris

I was recently asked by the New Zealand Forest Owners Association to critique the statistical methods that are commonly used to estimate the volume of woody debris at a site. This work arose out of the need to assess the proportion of woody debris (by volume) that came from forestry operations after Cyclone Gabrielle hit the North Island of New Zealand recently. The work was really interesting, as some of the methods involve probability calculations similar to those described for Buffon’s Needle Problem.