"Pollarding" is a much misused term. Cutting the top
off a tree and hoping it will grow back is not pollarding, whatever
the man with the chain saw may tell you. Pollarding is a treatment
that is given to young trees in order to make them grow with a
short trunk and a bushy canopy so that they can be maintained
by regular removal of young growth. Unfortunately people still
try to pollard ancient yews, and in doing so they invariably kill
them.
Here are two cautionary examples.
At Privett there is a beautiful but seldom used church which
is an important walkers landmark due to its raised position and
very high spire. Also there is the stump of a yew that is about
eight feet high, and between 25 and 30 feet in girth, depending
how far up the trunk you measure it. It has heaved a bit, and
the stump leans a few degrees towards the church, which is perhaps
10 meters away. It's fairly clear what must have happened, the
tree got shoved in a high wind, and started leaning. When this
happened, those responsible, considering the fabric of the church
and the safety of celebrants decided to have the top off the tree
in no uncertain terms. All that remains is a huge bole covered
with chainsawcuts where large branches have been removed. There
is not the slightest sign of life: the stump has lost its bark
and is rotting. A less dramatic remedy would certainly have served,
and this yew, once one of the 100 largest alive in the country,
might easily have been saved.
Another example of the outcome of this treatment is found in
Soberton churchyard. Here a great stump stands to the north of
the church, 23 feet in girth, and 7 high, smothered in ivy. It
had an enormous internal stem hard up against the east side of
the trunk; this formation was itself six feet in girth and at
least 400 years old. No one seems to know why the branches were
cut off this tree, but the treatment clearly killed it.
Here then are two examples of death by so-called pollarding in
yews both considerably over a thousand years of age. This is quite
obviously a treatment that should never be carried out. Looking
at it another way, I have never heard of an example of an ancient
yew surviving total limb removal, and there is actually a perfectly
well understood scientific reason (called the "mass to energy
ratio") why this might be a fatal treatment for an ancient
tree of any sort.
