Cutting or Burning ?
Technically, burning is best because old heather regenerates (from seed or rootstock) quicker and fire destroys the litter which can harbour ticks. The regrowth is more nutritious when burnt rather than cut but estates need not worry if they find burning is too difficult due to climate, lack of manpower or close proximity to forestry.
There is no scientific evidence that burning produces more grouse than a precision cutting system. The superior chick rearing environment within NSM can easily offset the nutritional advantage of heather in a burning rotation. The most productive grouse moor in British Moorlands portfolio of managed moors produces just under 200 brace per 1000 acres without any burning for over 40 years, and the other moors were run for 8 years without any burning. All have produced much more grouse per unit area than local moors with traditional burning.
Cutting, using a horizontal chainflail and a 100hp. 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 can be 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 cut.
- 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) may 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 20 yds x 100 yds, the area burnt is 10 acres per day or 2 acres per man/day. A tractor 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.
CUTTING vs BURNING
Both techniques can be valuable to grouse moors. Assuming a moor is lucky enough to have about 40 burning days a year, what happens on the remaining 160 days of access time on the moor ? Instead of wasting it waiting for burning weather the keeper can keep going with installing NSM.
Burning is most efficient when used to burn large acreages per day. This is good for creating long wide strips for firebreaks.
If not too dry and winds are light a great number of small fires can be made in a day by lighting the small squares of heather created by the NSM. This must be done within an area surrounded by previously made firebreaks in case the wind changes direction or speed and the fires cross the cuts, but in the right conditions many very small fires can be run at the same time to spread the benefit over a wider area. NSM cuts can be widened to 2 or more to help in containing fires and in tall heather the wider cuts help the grouse to see any approaching danger. The wide strips, bare patches and firebreaks are favoured as roosting sites.
If there is significant grazing by deer, sheep etc heather burning must be extensive enough to provide for this, as animals prefer to graze heather from fires rather than cuts. A few small fires can readily lose their heather to overgrazing.
What to cut and what to burn ?
As the number of burning days is limited, burning should be concentrated on heather which will not recover well from cutting. This will be mainly very mature heather which is becoming degenerate.
However, even this can recover quite well from cutting if the site is damp and/or sheltered and warm but the first few years may show little sign of growth. This can also apply to “cool” fires. As regions and sites vary so much, trial and local experience will be needed. Comparisons can also be seen where firebreaks were cut around old fires.
Next section: Predator control