Stop fires from picking up momentum

April 18, 2017

Fire breaks like this arranged in a grid throughout the plantation help to stop runaway fires.

Keep it small and simple (KISS) fire protection model to prevent runaway fires...
By Michael Olivier

I can remember during my years in forestry, when the berg wind was whining, how I wished that the whole plantation was like a grid with a firebreak every 50 meters in either direction. That would mean that there would be a good chance that a fire would stop by itself before it could build momentum.

After those big fires in Mpumalanga and Tzaneen last year, I thought about it again and realised that it is indeed financially possible to implement the KISS fire protection method. When fully implemented, it would cost less than 60% of a standard fire protection budget to disc a grid of 4.8 meter wide firebreaks every 50 meters over the whole plantation annually (where the terrain is not too steep or rocky).

Alternatively, it would cost less than 30% of a standard fire protection budget to disc a 2.4-meter wide brake every 50 meters).

I would strongly recommend that any new afforestation project should consider implementing the KISS Fire Protection Model. It would be easy to implement.

Spacing with afforestation & regeneration
One of the main causes of runaway fires is because plantations are planted at a spacing that restricts access and makes it very difficult or sometimes even impossible to get to a fire quickly, if the fire is not close to a road.

With the KISS fire protection model you plant your trees at your normal spacing, but every 50m you leave a 6m gap which is not planted.  In the rows, you also leave a 6m gap after every 50m.

If this is implemented the whole compartment (and eventually your whole plantation) will be divided into 0.25ha ‘islands’ with a 6m opening around.

To end up with the same number of stems per ha, you would need to plant the line of trees running alongside the gaps closer to each other. This would compensate for the number of trees lost due to the 6-meter gap. These 6m gaps are then disc’d every year to a width of 4.8m. You will need to do two trips in the gap with a 60kW 4x4 tractor with a 2.4m off-set disc to create the needed 4.8m firebreak.

With regeneration in mind, the 6-meter gap should be left open for accessibility every 50 meters. With current thinning operations, the 6-meter gap every 50 meters can already be implemented. After 10 years (in pine) when the stems have rotted, these gaps can then be ploughed to implement the KISS Fire Protection Model.

SWOT analyse for KISS Fire Protection Model.

•    Prevent fires from gaining momentum
•    Less stress for forestry staff
•    Plantation is much more accessible
•    Fire protection much easier
•    Financially viable
•    Easy to implement with afforestation in certain areas
•    Gives fire crews more efficient/cleaner access
•    Disc breaks will restrict many fires to 0.25 ha without further human intervention
•    Arson damage greatly reduced

•    Old tree stumps hinder effective implementation of KISS Fire Protection Model – in pine plantations only effective after 10 years if stems are left to rot
•    Breaks need to be de-stumped for hardwood regeneration plantations
•    Old riparian vegetation zones - fire hazard threat in plantations
•    Difficult to implement in rocky and steep areas where it is not possible to disc breaks

•    Prevention is better than cure
•    A proactive step to counter consequences of climate change
•    Less need for expensive aerial support
•    More planning needed with afforestation and regeneration
•    Use firebreaks to cut riparian zones into patches smaller than 0.25ha
•    After forestry operations, breaks and roads need to be cleared 5 meters on either side of branches

•    Old-School resistance to change
•    Riparian zone policy for plantations - causing “bombs” in plantations

Where in the world will you find a commercial business whose commodity is highly flammable material, but their own policy stipulates that “bombs” must be kept close to their product. This increases the risk of fire.

Costing for this exercise
Work tempo (ha/hour) = Work tempo (4km/hour) x Work with (2.4 meter) x Working efficiency (80%) ÷ 10  = 0.768 ha/hour
Running cost/hour: 60kW 4x4 tractor = 273.85;  2.4m off set disc = 214.15;  D/O =  62.00;
Total = R550.15  /hour
Cost of ploughed fire break = R0.34/meter (4.8m wide)
Protection cost of each 0.25 ha (island) with 4.8m firebreaks ploughed around it = R34.37

*First published in SA Forestry magazine, Feb 2017

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