Really great post TreeCo, one of my favourite pet subjects fungi and trees.
There really is masses of work being done in this field and new understandings are being gained almost weekly. Here's a bit of research from your side of the pond back in 97' I think from the Connecticut Exoerimental Agricultural Station they did and do really good work, here's the web address;
http://www.caes.state.ct.us/Default.htm
and the paper;
PP044.doc
The better we get at understanding that although the tree trunk and branches, and leaves look clean and smooth, its covered with fungal spore growth, bateria paramecium etc.. and on the inside its just as cluttered with fungal mycelia attempting to colonise wood tissue...the better we will become at assiting in the management of our trees whereever we might be.
SF