Burnham Beeches Management Plan 2010 - the City of London ...

2 the need for Management - pollards
2.1 The importance of managing the pollards
Areas with ancient beech pollards are rare. In Britain there are
just three sites with over 100 such trees and those in Burnham
Beeches are particularly fine examples. In a worldwide
context, only Romania and the Basque Country have more
than just a small handful of these trees and the climatic
conditions in these places mean that many of the species
associated with the pollarded beech trees there are different.
Pollarding enables beech trees to live much longer than
those left unpollarded (maidens): they can live for over 400
years rather than the more normal 250. The aging process,
together with the pollarding action gives the trees their
characteristic and knobbly shape. Rainwater and fungi
slowly break down the dead wood in the trunks of the
trees - this does not harm the tree but is a natural aging
process. These water and decay pockets provide ideal
conditions for invertebrates and the aging process enables
species of moss and lichen to live on the bark of these
trees rather than younger ones.
Once the process of pollarding has started it needs to be
continued. Trees uncut for many years develop very large
and heavy branches, become unstable and fall over or fall
apart. This is just what has
happened in Burnham Beeches.
The pollards were last cut regularly over 200 years ago.
This, coupled with the cessation of grazing by the 1930’s
(leading to new young trees growing around the old
ones), means that the branches reach up high for light as
well as growing larger in girth. By 1980 many of the old
pollards were becoming very unstable. In addition there
was no new generation of pollards as the youngest were
still probably 350 years old or more.
It was estimated by a forester in the 1930’s that at one time
there may have been over 3,000 pollards in Burnham Beeches.
By 1990 the number had declined to 550 and by 1999 the
trees were dying at a rate of approximately 8.5 every year.
Since then a programme of restoration work was started
but restoring lapsed pollards was a new science - one that
staff at Burnham Beeches were in the forefront of
developing. Techniques have been refined over the last
20 years, but we are still learning. The rate of loss of the
old trees has now declined to less than 6.4 trees every
year. Continuing this work programme, which also
includes work to create new pollards for future, is an
important part of our work.
In addition, grazing needs to be reinstated to all areas
with pollards in order to stop scrub and young trees
growing up and stopping light from reaching the old trees.
(1) (2) (3) (4) (5) (6)
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1: A tree pollarded regularly and in
a grazed system.
2: A ‘lapsed pollard’. It has not been
cut for many years: the branches
are tall and heavy. Young trees
grow aound it because grazing has
stopped.
3: Wind and the weight of the
branches make the tree unstable
and vulnerable to wind damage.
4: Old pollards can be restored.
First stage of restoration: young
trees are cleared from close to the
pollard and there is a gentle
reduction in the height and weight
of the branches.
5: Second stage of restoration: there
is a further reduction in height and
weight on the branches; a little
more clearance of young trees has
been done.
6: After several restoration stages
the pollard is much lower again and
more stable. It is now cut on a
regular cycle. New pollards are
nearby to replace the old ones when
they die. Animals graze underneath
them once again.