Glad to see Philip's ppt is freeware, great stuff!
Thanks for that thread, 6 years old but not outdated imo. Sure would be great to see a 2013 image of those trees!
The manual's focus on other organisms leaves a lot to say about pruning to retrench, and no one from the UK including the Morphogene has detailed it clearly yet. Much easier said than done.
Fools rush in--Friday Nov 15 8 a.m. (groan) at Expo there'll be an effort to plug that gap a bit. An 8-page handout will synopsize the best available info (Expo encourages paper handouts, while many chapter conferences have gone digital).
Google Coder Arboritecture, and Goodfellow John 2009, for a fresh look at pruning. (Why don't pdfs attach here?)
Retrenchment first referred to soldiers who retreated back to a line they could defend, where landforms and supplies allowed them to dig in and fight anew. This concept relates very well to declining trees, so before cutting any branches to reduce the size of the canopy, visualize the new canopy outline.
The objective is to make reduction cuts so that branch tips are left intact on the new, smaller canopy. For trees with strength loss at the base, as little a 15% reduction can increase strength by 50%