Work in progress

Visited the rather lovely Hardwick Wood today and came across the area that's currently being coppiced. I've never seen this kind of device before but it looks exactly right for supporting the poles while the brash is cut off. 

The extras: the white spike is a mystery to me. Is it fungi, lichen or something else? On contact the white stuff is flaky and fine . Any ideas? 
The other extra is part of a fallen ash tree.