Fen Management Handbook - Scottish Natural Heritage

6.5.2 Methods of Scrub Clearance
124
Scrub clearance from an
area of fen at Betley Mere
SSSI in Cheshire. The cut
stumps have been treated
with herbicide to prevent
(or at least reduce) the
amount of scrub regrowth
(B. Hamill).
The table below summarises the most common methods of scrub clearance and
disposal of the cut material.
Method
Hand clearance by volunteers or
contractors using manual saws or
chainsaws. Scrub is normally cut at the
base of the trunk. The material is then either
burned on site at a designated bonfire site
or loaded into a chipping machine. All cut
stumps should be treated with herbicide to
prevent re-growth.
JCB Excavator removes the entire tree
including the root system by pulling/
pushing and digging around it. Some
machines include facility for stump grinding.
Woody material can be buried under
spoil banks if the operation is combined
with dyke restoration, or chipped, burned
or transported off site. If chipped, the
material should be removed from the site
unless spreading is known to be harmless
or beneficial. In some cases the chipped
material can be used on site to create
paths.
Typically the machine weighs 8 tonnes
with a ground pressure of 4.5 psi (pounds
per square inch). It travels around sites on
tracks using existing banks, but can also
run on the fen itself if dry or on mats if the
surface is too wet. The mats weigh 1ton
each and reduce the ground pressure of
the machine to 1.09 psi.
Advantages/
suitable sites
Small and
inaccessible sites
A single machine
can restore dykes
and remove
scrub in the
same operation,
maximising
efficiency and
cost-effectiveness.
If scrub is
burned, no need
for additional
machinery on site.
No stumps remain
to produce
regrowth.
Large scrub can
be tackled by
digging around the
roots and pushing
the tree over.
Disadvantages Examples
Labour intensive
Expensive
Heavy machinery
causes compaction by
repeated passes when
tracking directly on the
fen surface.
Pulling the entire
tree from the ground
leaves holes within the
peat and destabilises
the surrounding
surface, which creates
problems for both
livestock and mowing
machines and the
surface may remain
unstable for a number
of years.
There can be a huge
amount of woody
material for disposal.
Norfolk and
Suffolk Broads