As mentioned, dangerous branches can be separated from dangerous
trees. The tree in question certainly had some risky branches, a
fact that had been pointed out to TAMS some time ago. For whatever
reason this advice was not acted upon until one of them fell
recently. Now after some attempts to get quantified information on
the integrity of the tree (which may or not have been completed and
may or not have supported drastic action), TAMS presumably used
advice from the consultant Ian mentioned and then elected to do what
they did i.e. remove all but the tall stump immediately. From the
point of view of the tree, it would be interesting to see any hard
evidence that was used to support more than lopping one or two
remaining risky branches. No information has been made available
publicly which is unfortunate given the feelings of some interested
parties and some (non-professional) post-felling opinions that the
tree appeared fundamentally sound (which if true would be contrary to
what Ian's expert reported).
From the point of view of the nesting Gang-gangs, I can't for the
life of me understand why it wasn't possible to leave the
felling/lopping for another couple of weeks until they fledged, with
whatever precautions may have been legally necessary in the meantime.
The decision making process in Canberra re tree safety activities is
not transparently functional despite recent publicity and discussion.
re trees having dangerous branches without being themselves a
risk... interestingly in a COG context, I only learned tonight and
maybe some others haven't picked up on this either, one of the
significant causes of trees dropping branches is the direct result of
Cockatoos. I knew galahs would chew around tree hollows but had no
idea of how active they are in other areas. There are some excellent
examples very close to the Tree In Question of some that have been
dramatically chewed by Galahs(?) around the area where branch meets
trunk i.e around the fork. This often leads to rot, failure to grow
and loss of strength to the extent that those branches eventually
fall prematurely. It has been suggested that this behaviour might
even be proactive, instinctive hollow-making behaviour since
then-fallen branches often leave a nice hollow. Arborists sometimes
go to considerable lengths in domestic environments to prevent
cockatoo access to these vulnerable areas. This preventive measure
doesn't yet seem to have made its way to government pro-activity,
even for notable trees or especially risky trees. Anyone who is
interested in this behaviour can see some great examples in the trees
around the Tree In Question - especially the tree to the right or
left of the blue marker on this map ...
<http://maps.google.com.au/maps/ms?ie=UTF8&hl=en&msa=0&ll=-35.267188,149.142221&spn=0.002729,0.003401&t=h&z=18&msid=109598757085709980006.00047b634eeb4ea3aa1af>
I think E Manniferas are particularly affected -- I wonder how much
of their 'brittle' characteristic is due to the fact that their bark
seems to attract the best attention of Galahs?
Julian
At 09:38 AM 23/12/2009, Peter Ormay wrote:
The tree itself may be less likely to fall because of the reduced
windload and the weight on it but the branches are more likely to
fall because of the weakened tree, often an empty shell and often
weakened branches due to termites and rot.
Peter
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