 Technically,
burning is best because old heather regenerates (from seed mostly) quicker
and fire destroys the litter which can harbour ticks. It can be done on
terrain where tractor operated cutters cannot safely go. Heather under 370mm
when cut, regenerates as fast as burned heather.
Cutting, using a horizontal chainflail and a 100 H.P. tractor, has many
practical advantages:
- Precision cutting, to achieve micro habitats, is easy. To use a
cutter to imitate the patch work quilt of burning is to waste its potential
for habitat improvement.
- Timeliness: Due to weather & available labour, the number of safe
& effective burning days is only 10-30 days per year. This problem is
increasing due to the warmer climate encouraging faster heather growth
and shorter intervals between burning. Thus it is difficult to burn
the ideal acreage each year. However the number of cutting days is usually
about 200 per year, allowing for about 40 lost due to snow or fog. On
easy ground it is even possible to run a cutting rig at night, and rain
is no problem.
- Grit - may be exposed when the flails cut into the soil.
- Layering of heather is enhanced. When mature heather is cut, some
of the uncut stems which are not vertical will droop down into the cut
area. This results in fresh young shoots from these stems specially
if they touch the ground and form adventitious roots. The feeding area
of young shoots then has up to 2 x 1 ft of vertical "hedge" sides added
to each 4 foot cut. Such a 50% increase is valuable, so research is
examining mechanical systems on the cutter, or behind it, which will
help the layering process.
- Relative costs need exploring because cutting is often wrongly assumed
to be slower and more expensive than burning. Field comparisons show
that safety (and insurance companies) require a burning team of 4-5
people. A tractor and cutter will often be used for fire breaks along
with water jet fire control equipment. So burning does not require any
less machinery than cutting. The team can burn 10-40 fires per day depending
on conditions. If we assume an average of 20 fires per day of 20m x
100m, the area burnt is 10 acres per day or 2 acres per man/day. A heather
cutter can cut 1-1.5 acres per hour or even up to 2 acres in good conditions
and this produces 8-12 acres per day i.e. as much as burning but with
only one quarter or one fifth of the labour cost (machinery costs being
equal), no wild fire risk and much greater operator comfort.
- Costs of distributing grit are almost nil as the grit is dispensed
from the cutting tractor at points where the cuts cross.
Next section:
Better Predator Control
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