I was recently informed in no uncertain terms by an authority on the subject that removing rubbing branches is no longer considered good practice in tree work. The justification is that they provide natural bracing.
I have subsequently tried to verify this information but come up blank.
BS3998 (10.5.2) clearly states that rubbing branches should be prevented by means of pruning (or failing that by bracing)
Gilman's 'An illustrated guide to pruning' (2nd ed) (p.205) also states removing rubbing branches as part of established tree maintenance (as well as crucial formative pruning)
Whats going on here then? Two hypotheses are that (1) best practice guidelines have updated on this matter since the publication of these materials (2010 and 2002 respectively), or (2) best practice holds that branches which merely cross but do not abrasively rub should be kept (and I failed to glean this subtlety from this authority) - which seems plausible although I've not seen this written anywhere.
Common sense seems to indicate to me that each case of crossing/rubbing branches be considered individually and a context-specific judgement be made which weighs up the relevant factors. It also seems logical that in cases where one branch rests upon another, there should, all else equal, be a general preference for removing the top branch since this is the one which was in receipt of the greatest support and is thus most likely to fail if suddenly alone.
Can anyone shed any light on this? Ta
