and scrub clearance, heather cutting, turf stripping and grazing
Loss and fragmentation of heathland in Surrey is still continuing.
By far the greatest threat is encroachment by trees, scrub, bracken
and grass and the loss of species diversity resulting from a cessation
in traditional management. Heathland is no longer integrated into
the economy of the county and many areas are now managed for their
nature conservation and recreational value. The Agri-environment
schemes, Countryside Stewardship, Wildlife Enhancement Scheme and
Reserves Enhancement Scheme have had a considerable effect in funding
management in recent years.
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Tree and scrub clearance, heather cutting,
turf stripping and grazing
A major part of heathland management is removing young trees (often
referred to as ‘scrub’) to prevent the heathland being lost to developing
poor quality woodland.
In Surrey, the main problem tree species are Scots pine and birch,
sometimes also oak and sallow. A major part of heathland management
is preventing these trees from taking over. Pines, when cut close
to the ground do not survive but other species ‘coppice’, sending
up several new shoots. In order to kill this scrub, it is usually
necessary to treat the cut stump or the regrowth with a herbicide
such as ‘Roundup’. Where there is grazing, this might control the
regrowth and kill the stump without the need for chemical.
When invading trees have taken over heathland, this ‘secondary
woodland ‘(so called to distinguish it from ‘ancient woodland’ which
has a much longer history and is much richer in wildlife) can be
restored to heather. Heather seed can survive several decades in
the soil so, if a site has had heather – even 80 years before –
all that may be needed is to cut down the trees and heather will
grow, though usually stripping off any layer of leaf mould or pine
needle litter speeds up the process. A long-arm excavator is the
most common piece of machinery to carry out this task, though rakes
and wheel barrows work equally well on small areas! Areas of grass
and bracken litter can be treated in the same way.
Litter or turf stripping can also be very effective in restoring
heather in areas which have been taken over by bracken or the sometimes
the aggressive grasses, wavy hair-grass and purple moor-grass. The
bare ground initially left by these operations can be very valuable
for heathland invertebrates such as solitary bees and wasps.
The age of heather stands can be controlled by cutting, giving
diversity in the heathland habitat, to the benefit of a range of
heathland wildlife which depends on different ages of heather. Regular
cutting also maintains the vigour of heather stands. To prevent
build up of organic matter and fertility which is to the detriment
of heathland, it is necessary to collect the cut material so cutting
is usually by forage harvester into a trailer. Cutting produces
enormous volumes of material, hence is mainly used for cutting fire
breaks to help stop fires spreading across the heath.
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Burning of heather stands can be very effective at promoting their
regeneration, particularly as, unlike cutting, the burning may remove
some of the accumulated organic matter under the stand. Controlled
burning needs skill to achieve the best results and ensure that
the fire does not get out of control. Ideally, it is done in late
winter to minimise damage to heathland wildlife.
Burning is an ancient practice, and a recognised form of heathland
management, especially on Britain’s upland moors, but also in areas
such as the New Forest. Surrey, however, is no longer the wild uninhabited
place it was at the end of the 18th century. Even our wildest areas
are not far from roads, housing and businesses, and a deliberate
"management" burn on any of these areas needs to be carefully
planned. As burned heathland is an extremely good firebreak, managing
heaths by controlled burns has the benefit of helping to prevent
large areas being burned by summer wildfires.
Uncontrolled burns during the summer months often caused by arsonists
or carelessness can cause long-term damage to heathland and its
wildlife. In summer, heath fires burn much hotter – especially if
there is a covering of scrub. There is a greater chance that heather
rootstocks will be killed by a summer fire and sometimes a summer
burn is so severe that even heather seed will be killed. Summer
burns will kill any wildlife unable to move quickly enough. See
link to ‘fire awareness‘.
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Grazing by domestic livestock can benefit heathland in a number
of ways. It can reduce the amount of scrub that develops, as animals
graze off seedling trees. Grazing can promote diversity of flora
and fauna by reducing the dominance of grasses such as purple moor-grass
and wavy hair-grass. Grazing can promote ‘structure’ in the vegetation
to the great benefit of heathland wildlife. It can also benefit
heathland invertebrates that make use of dung. Different grazing
animals – cattle, ponies, sheep and goats – will have different
effects on the vegetation. The nature of the site – its size, topography
and the make-up of its vegetation – and the level of stocking are
also important determinants on the effects of grazing (please see
‘Grazing‘ for further details).
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In recent years, the spread of bracken has become a major problem
on heathland. It could be that the bracken, like grasses, is benefiting
from nutrient enrichment through air pollution. The vigour of bracken
can be reduced by mechanical treatment – regular cutting or rolling,
especially with a special roller called a ‘bracken bruiser’. Mowing
and rolling are most effective when done when the bracken frond
has just finished unfurling and food reserves in the underground
root system (rhizome) are most depleted. This is also the time when
it is best to treat bracken with a herbicide. Usually on heathland
the selective chemical Asulox is used for this and, in normal circumstances,
it does not affect the growth of plants such as heathers that may
be growing with the bracken.
There are disadvantages to the mechanical methods of bracken control.
Regular cutting keeps all vegetation short and rolling works best
where the vegetation is short, this makes control of bracken in
taller vegetation a difficult proposition. Both methods can harm
Under dense stands of bracken, there is often a thick layer of
litter that it is frequently useful to strip to allow heathers and
other heathland plants to re-establish.
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