Discovering the cause and origin of a destructive wildfire

Fire expert Dave Dobson was hired to find the cause and origin of a wildfire that left a swathe of destruction across farms and forestry plantations in the KZN midlands in 2007. Working years after the event, Dave followed the trail of smoke to uncover the origin of the runaway fire that burnt thousands of hectares to a cinder …

The dispute surrounding the ‘Kentucky’ fire of 25th June 2007 that devastated farms and commercial forests in the Curry’s Post area of KwaZulu-Natal has eventually been settled. The fire caused extensive damage to privately owned farms and commercial forest plantations in the area.

As a result of the fire one of the plantation owners instituted legal proceedings against the owners of two properties where the fire was purported to have originated. This case study deals with the case against the second Defendant, the owner of the farm Kentucky.

The challenges
The objective of every fire investigation is to establish the cause and origin of the fire and to determine the ignition sequence.

The first challenge, and one that is regularly encountered in work of this nature, is the fact that I was appointed to investigate the origin and spread of this fire on behalf of the Defendant some seven years after the event (i.e. in 2014).

The Defendant was not a member of the local Fire Protection Association. This raised two issues. The first was that the Defendant was deemed negligent in the event of a fire originating or exiting his property and the onus rested on the Defendant then to prove his innocence. The second issue was that the Defendant was denied access to information held by members of the Fire Protection Association. This was particularly important in respect of the origin of the fire under investigation.

Other issues that contributed to the charge of negligence against the Defendant related to the presence of a compartment of plantation waste/slash located on the boundary between the Defendant’s farm and a neighbouring commercial forest plantation. This was deemed to be a fire risk which contributed to a massive flare-up that resulted in the fire spreading to the Plaintiff’s plantations.

The fires
A number of fires occurred during this period. The first two occurred on the property adjoining Kentucky Farm (St Clair Estate) while the third, as will be shown later, arose on Kentucky Farm. This led unfortunately to the fire becoming known colloquially as ‘the Kentucky Fire’ which was not entirely correct!

The first fire (fire A) occurred on Sunday 24 June 2007. It was extinguished on St Clair Estate (Kentucky’s neighbour) and played no further role in the events that unfolded the following day.

The second fire (fire B) started on the morning of Monday 25 June 2007 on St
Clair Estate and swept through Kentucky Farm fanned by extreme weather conditions.

A third fire (fire C), that was not reported, started on Kentucky Farm during the afternoon of Monday 25 June 2007. This is the fire that resulted in the extensive damage to commercial plantations and farms in the area, which was the focus of this lawsuit.

Data collection
I approached the investigation in a systematic manner beginning with a site visit and an interview with the Defendant. This proved useful in providing circumstantial evidence tracing the progress of the fire through the Defendant’s property. Of particular importance however, was acquainting myself with the overall fire area which was to prove beneficial later in the investigation.

Empirical data was collected in the form of weather data during the time of the fire, interviews and fire reports from various parties who were involved in fighting the fire as well as photographs taken from the spotter aircraft monitoring the fire. A vital piece of evidence was pictures taken of the origin and spread of the fire recorded by Fire Hawk’s locally based fire tower. This information was not readily available to the Defendant since he was not a member of the local Fire Protection Association. However, the picture sequence of the fire was in the public domain as it was being used to conduct Fire Boss Training courses. A simple request for the pictures provided access to this vital piece of information!

In addition, and rather late in the day, an Expert Report was received from the Plaintiff’s legal team.

Cause and origin of the fire
Once the data had been collected and analysed it was possible to develop a hypothesis of the events that occurred on this day. This hypothesis was then subjected to systems analysis to develop a broad understanding of what happened and to avoid linear thinking. This initial hypothesis is depicted in the following diagramme.

In developing this initial hypothesis consideration was given to the summons which suggested that the fire originated from the Sunday night fire (fire A) that had – according to the summons - not been properly extinguished. Various witness statements however refuted this contention. Furthermore, picture evidence obtained from the Fire Hawk camera appeared to indicate that the fire that damaged the Plaintiff’s plantations originated near some homes on the neighbouring St Claire Estate and was the result of a member of the household throwing out ash from the previous night’s hearth fire during the morning of Monday 25 June (fire B).

When examining a problem systematically there are tools in systems thinking that can assist with an enquiry. Systems archetypes are one such tool. As one works with the problem, developing the story, identifying the key variables and sketching them in causal loop diagrams, patterns begin to emerge which provide keys to unlocking parts of the problem. These generic patterns are described in systems thinking as archetypes (Kim, D., H. and Anderson, V. 1998).

A typical “Escalation” archetype now emerges where discarded ash from a previous night’s fire catches alight and starts a fire (fire B). This fire later enters the plantation slash on Kentucky and under deteriorating weather conditions escapes causing havoc to farms and commercial forest plantations down wind. This served as an initial hypothesis for testing against further empirical evidence.

The crucial evidence related to the slash in an old pine compartment located on Kentucky Farm, adjacent to the boundary between Kentucky farm and a neighbouring commercial forestry estate. The trees in this compartment had been clearfelled six years prior to the fire and most of the plantation residue would have decomposed by the time of the fire. Nevertheless the Plaintiff’s Expert presented pictures showing clear lines of fire burning in the old pine compartment which were ascribed to the brush piles having caught alight. The picture also clearly showed a road in the area.

I was aware that no such road existed and began searching for an answer to this conundrum. It turned out that the fire depicted in the photographs was actually burning on a property on the other side of the Curry’s Post road some 1.5 km away! The owner of the property was contacted and confirmation was received that he had in fact cleared and stacked jungle wattle and gum in this area of his farm a few months prior to the fire! The picture of the plantation slash burning that was presented as evidence of negligence on the part of the Defendant was incorrect – the photos were of another property on the other side of the Curry’s Post road.

It was time to test the validity of the evidence of the fire entering and escaping from the old pine compartment on Kentucky Farm.

A closer inspection of the photographic evidence of the fire in the section of Kentucky farm bordering the commercial forest revealed further interesting empirical data. The first was clear evidence – i.e. straight line burns - of firebreak burning in kikuyu camps adjacent to the old pine compartment on Kentucky. Wild fires do not burn in straight lines. From the available photographs it was evident that the party responsible for initiating this firebreak burn lost control of the operation resulting in it entering the old pine slash compartment on Kentucky farm, and subsequently the neighbouring forest where it was brought under control by the land owner. However, the fire in the old pine slash compartment on Kentucky continued to burn. This was fire C.

The events leading to the origin of this fire were never reported, although mention was made in a fire report of drip torches being issued to a helitack ground crew who were dropped in the area in an effort to mop up and contain the fire.

Soon after this, evidence of the fire break between Kentucky and the commercial forest plantation being half burnt indicated a further attempt to contain the fire. The Expert for the Plaintiff (who had previously been contracted by Kentucky’s neighbour to prepare a report on the fire) mentioned the “application of a counter fire along the land owner’s boundary closing up to the main plantation road.”

Clearly there were numerous attempts to introduce counter fires and fire-breaks along this boundary under extreme weather conditions.

At the same time as fire C was burning in the old pine compartment on Kentucky farm, a power failure at the landing strip where the water bombers were refuelling delayed their return to the fire. A further complication arose when weather conditions became too dangerous to fly. Eventually the fire exited the old pine compartment and was driven, out of control, by the extreme weather conditions across many farms before entering the Plaintiff’s commercial pine plantations where extensive damage was experienced.

Final hypothesis
It now becomes possible to develop a final hypothesis describing the fire. This hypothesis is summarised in the diagramme that follows.

Initially as mentioned a preliminary hypothesis was considered which was represented by an “Escalating” archetype: Discarded ash catching alight and resulting in the fire spreading onto Kentucky Farm from whence it enters the slash in the old pine compartment and later spreads to neighbouring farms and forest plantations (fire B).

However, on further investigation a second archetype emerged – a ‘Fixes that Fail’ archetype where an unintended consequence of the use of counter fires or fire-breaks set in an effort to contain fire B, results in the fire escaping and entering the old pine compartment on Kentucky farm from whence, after a delay (indicated by the parallel lines) the fire enters farms and commercial forests causing immense damage (fire C).

An interesting addition to the overall picture is the loop linking Curry’s Post road to the main fire. Pictures of the windrowed plantation slash on a property some 1.5 km away from the Defendant’s farm across the Curry’s Post road from the Defendant was presented as evidence of negligence on the part of the Defendant. This was shown as being clearly incorrect!

Results
After careful consideration of the evidence and interviews with people involved it became clear that the Defendant did not act negligently.
The unintended consequence of trying to “fix” the problem of fire B exiting Kentucky by burning counter fires and fire-breaks on the Defendant’s property is the probable cause of the subsequent damage to farms and forests downwind of Kentucky. This counter fire activity was never reported.

The evidence presented of the extreme fire danger posed by the plantation slash on Kentucky plus the photographic evidence of windrowed slash burning in support of this claim was refuted.
In the end the Plaintiff’s summons was deemed to have no substance and was subsequently withdrawn. The Plaintiff ended up having to pay the Defendant the cost of suit.

References
KIM, D., H., ANDERSON, V. 1998. Systems Archetypes Basics. From Story to Structure. Waltham Massachusetts, Pegasus Communications Inc.

New association for wildland firefighters launched

A new association for Wildland Firefighters has been launched in South Africa. The Association for Wildland Firefighters (AWF) represents the wildland firefighting industry and associated professionals in Southern Africa.

“Numerous investigations into some disastrous fires in Southern Africa highlighted the need for a formal body to represent the needs of the wildland firefighter. The AWF aims to develop the knowledge, skills, understanding and competence of wildland firefighting in South Africa,” says Etienne Du Toit, the chairperson of the AWF.

Du Toit says the organization aims to improve the standards of safety and the working environment for firefighters in the sector in which its members operate.

The Association is registered as an independent, non-governmental, non-profit organisation. Any person or organisation associated with the wildland firefighting/integrated fire management fraternity qualifies to be members.

Du Toit says that climate change has resulted in a significant increase in wildfire risk, not only to responders but also to civilians.

“Monetary losses and other damages as result of these fires annually exceeds hundreds of millions. More needs to be done to address these risks. This is where the AWF comes in, an organisation that aims to share learning in such a manner that it promotes professionalism, reduces responder and civilian risk and at the same time allows for continuous improvement in all aspects of integrated wildfire management.”

The new association specifically addresses the needs of the wildfire fraternity.

“Until now, no other association specifically addressed the needs of the wildfire fraternity, there are similar associations but these are more focused on the structural firefighting sector,” says Du Toit.

The founders of the organisation come from a variety of backgrounds, including the fire service, forestry and conservation sectors and include business development practitioners with vast practical experience in these sectors.

“This Association seeks to enhance synergies between the various entities responsible for wildfire and integrated fire management, and one of the main aims is to professionalise the wildfire fighting industry in SA,” he said.

For more info contact Tessa Oliver at email: info@wildlandfire.org.za

www.wildlandfire.org.za

Preventing fires, planting trees & locking up carbon

A partnership between Fogmaker South Africa and the Platbos Conservation Trust is contributing to the reforestation of the unique Platbos indigenous forest in the Western Cape. What these two very different organisations have in common is a desire to prevent unwanted fires, and a deep concern for the environment.

Platbos, situated between Gansbaai and Hermanus, is Africa’s southern-most indigenous forest. Surrounded by fynbos, cultivated lands and encroaching alien invasive jungles, this unique, ancient forest is under threat and needs active management to survive.

Although it is situated in a fire shadow area, wildfires have over the years been encroaching on the forest margins and threatening this sensitive ecosystem which is rich in biodiversity and contains many ancient trees, some over 1 000 years old.

The Platbos Forest Reforestation Project is an NPO that aims to expand and strengthen the forest by removing alien invasive vegetation from the forest margins and planting indigenous trees that are endemic to the area. This crucial work serves to protect the heart of the forest from encroaching wildfires, promotes biodiversity and sequesters carbon to counter global warming.

Fogmaker South Africa decided to get behind this initiative by donating a tree for every Fogmaker fire suppression system that they install in forestry machines during 2021.

These trees are grown in the Platbos tree nursery before they are planted out in selected areas around the Platbos forest. The Platbos reforestation team follows up, watering the young saplings and doing general vegetation maintenance to ensure their survival

The Fogmaker connection
Fogmaker SA are the licenced distributors and installers of Fogmaker fire suppression systems across Southern Africa.

Fogmaker automatic fire suppression systems are manufactured by Fogmaker International in Sweden. The systems are designed specifically to protect engine compartments of mobile equipment – including forestry equipment – to prevent engine fires that have the potential to destroy expensive equipment, injure the operators, interrupt work schedules and set fire to surrounding vegetation including plantations.

Fogmaker systems attack all three sides of the fire triangle: oxygen, heat and fuel. When triggered by an engine fire the Fogmaker system produces a fine water mist. This water mist vapourises and expands when it comes into contact with any heat source and displaces the oxygen needed to sustain a fire. The water mist, containing a foam additive, discharges for more than 60 seconds and cools down hot surfaces, while forming a protective barrier on the surface of any flammable material, including fuel, to prevent re-ignition.

Fogmaker systems have been installed on a wide range of forestry equipment including harvesters, mulchers, chippers, forwarders and loggers, produced by leading suppliers like Hitachi, Tigercat, TimberPro, CAT, Bell and Pinoth.

See how the Fogmaker system extinguishes a simulated engine fire in seconds...

Hard-working forestry machines are always at risk of fire due to the fact that the fine vegetative material (leaves and sticks) that tend to get caught up in the engine compartments have the potential to catch fire due to extreme heat. The risk is increased as the dry, winter fire season approaches in the summer rainfall areas of South Africa.

Fogmaker SA’s innovative CSI programme aims to support the cause of preventing unwanted wildfires, but also to contribute to the reduction of carbon emissions which are contributing to global warming and climate change.

Since 2008, the Platbos Reforestation Project team has planted some 89 000 trees, with help from organisations such as Fogmaker, thus making a huge contribution to sequestering carbon.

Last year Fogmaker supported the African Honey Bee Project by donating a bee hive for several Fogmaker systems installed in customers’ forestry machines. This is an innovative project that promotes bee farming and honey production among rural communities. It includes training in responsible bee keeping, in particular how to smoke out bee hives without setting fire to the surrounding vegetation. This is a frequent source of wildfires in forestry plantations around SA.

For more info visit:-
www.fogmaker.co.za
www.platbos.co.za
www.africanhoneybee.co.za

Paraquat or not?

Paraquat - widely used in South African forestry to prepare tracer belts before burning firebreaks - is facing world-wide bans, forcing foresters to reach for the old-fashioned hoe. GAYNOR LAWSON reports.

It sounds so benign: “A non-selective herbicide - an aqueous solution contact herbicide for the control of annual grasses and annual broadleaf weeds in crops as listed and as a sugarcane desiccant. Inactivated on contact with the soil.” But this listed herbicide that contains Paraquat, “could have killed 2000 people” when maliciously used by a disgruntled employee to poison a tank of milk in the Cape in 2017, according to a News24 article. It is highly toxic.

Locally, Paraquat is extensively used to create tracer-belts as part of a fire management programme to prevent fires running out of control during the burning of firebreaks. The herbicide creates a boundary area devoid of vegetation before burning takes place. It is considered cost-effective, efficient and useful as it only desiccates the above-ground part of the vegetation (it leaves the root stock below ground unharmed), allowing for regeneration with the rainy season and thus preventing erosion or invasion by alien plants.

First produced for commercial purposes in 1961, Paraquat remains one of the world’s most commonly used herbicides, despite its potentially lethal impact on humans, either through deliberate poisoning or simply by working irresponsibly with it. It may be airborne when applied as a fine spray and can be spread through contact with clothing so it requires special training to ensure safe handling by users.

China reportedly experiences 5,000 deaths from Paraquat poisoning annually, although whether this is through accidental or deliberate poisoning is unconfirmed - Paraquat is known to be used in suicide attempts. It reputedly doubles the risk of Parkinson’s disease in those who come into contact with it, and the Michael J Fox Foundation issued an anti-Paraquat appeal on its website in October last year (the popular actor’s much-publicised battle with Parkinson’s has brought about heightened awareness of the disease): “Take action today to ban Paraquat. Your support can help protect people from environmental exposure to a known pesticide that increases the risk of Parkinson’s disease. We need your help to educate your Senators and Representatives…”

The appeal was posted in response to the reapproval by the Environmental Protection Agency (EPA) of several pesticides (including Paraquat) for use in the United States. The EPA reviews all herbicides and pesticides every 15 years to confirm they are safe for use, based on “assessments of human and environmental impact”. Despite its “well-documented harms”, the use of Paraquat in the United States “is at an all-time high, and it is one of only two pesticides still used in the United States that is either banned or being phased out in the European Union, China and Brazil”, according to the website.

Measures have indeed been put in place to control its availability. It cannot be bought or used in the UK (although, ironically, it is legally manufactured there), Thailand, Vietnam, Malaysia and the European Union (where it has been banned since 2007). It has been banned in Switzerland since 1989 because it is deemed too dangerous for use even when wearing protective clothing and equipment. In the USA, only commercially licensed users have access to it.

A complete international ban is apparently blocked by the US and developing nations whenever this is proposed. According to an article, “Poison on a plate”, which appeared in The Daily Maverick on 26 January this year, “It’s a shocking display of global north hypocrisy, allowing dangerous agrochemical companies to flood low- and middle-income countries for the financial gain and profit of European nations.”

The situation in South Africa
In South Africa, plantations certified under the Forest Stewardship Council (FSC) may not use Paraquat in any formulation that is available on the market. Gerrit Marais of the FSC Southern Africa Office, says: “Paraquat has been on the FSC Highly Hazardous list since the first pesticide policy was published way back in 2006. The figure below provides information on the reasons why this is done i.e., acute toxicity. Use of the product is thus not limited but prohibited unless it is approved, via a formal FSC process, for temporary emergency use. The South African forestry industry used to have a special derogation (exemption) for the use of this active ingredient and product, but this expired in 2020…Traditionally, the only alternative (to Paraquat) was to hoe the tracers by hand. This is, however, not ideal from an environmental perspective as hoeing often leads to erosion and thus this option – especially on steep slopes - is most undesirable. Some certificate holders have used other systemic herbicides (such as Glyphosate), but here too, the entire plant is killed and the risk of erosion is increased. The South African forestry industry is looking at other options…”

The stance of the Sustainable African Forest Assurance Scheme (SAFAS) – which has been endorsed by the other global certification body, PEFC - is that Paraquat can be used for tracer belt preparation, providing strict control/mitigation measures are in place. Steven Germishuizen, SAFAS general manager, says: “SAFAS supports the use of Paraquat from an environmental perspective because it is the best solution for fire management in grasslands. However, we acknowledge that it is highly toxic, so in accordance with our risk-based approach, we insist on strict precautions as far as training, use of PPE and application methods go.”

Craig Norris, NCT Forest Technology Manager, adds: “In addition to what Steve has said, we encourage an integrated approach to chemical use. In other words, the use of agrochemicals is the last choice of action and must be defendable. Agrochemicals can be detrimental to human and environmental health and will only be used after due consideration is given to other options/mitigation measures:
• Chemical control must be used in combination with above methods to minimise quantities used.
• Strategy for reduction of chemical use must be implemented.
• Chemical label specifications must be followed.
• Recommended safety, training, application procedures must be adhered to.

Steven comments: “We also encourage the use of technology, such as drones, to keep people away from the chemical. We strongly encourage exploration into environmentally suitable alternatives that are less toxic.” There is some experimentation with drone spraying currently underway in an attempt to cut humans out of the Paraquat-handling process almost completely.

What is the history behind Paraquat use in SA?
According to Dr John Scotcher of ForestLore Consulting in a report written for the FSC in 2014: “Burning green grass is not possible and, in any event, adversely affects biodiversity. In order to improve the safety aspects of burning firebreaks, a system of fire tracer lines was introduced which entailed the hoeing or ploughing of two parallel strips of vegetation approximately one metre wide (the fire tracer line) and 30 metres apart during the late summer to early autumn. These tracer lines are now devoid of vegetation and are used as lines from which to burn the intervening 30 metres (the firebreak) during winter when the grass is dry.”

The report continues: “Approximately 30 years ago, the use of chemicals was introduced as an approach that could be used where mechanical methods such as hoeing, ploughing or use of a brush-cutter was impractical and dangerous to use … normally on steep and mountainous terrain. Paraquat was first used in South Africa in 1982 by the nature conservation agencies responsible for the management of high-altitude grasslands in the uKhahlamba-Drakensberg Park, which is a registered World Heritage Site. The use of Paraquat in this mountainous region enabled the elimination of the historic use of hoed or ploughed tracer lines that resulted in soil loss and scars across the landscape, which even after 100 years are still visible to this day. Paraquat was soon adopted by the agriculture and forestry industry. Paraquat was ideal for use in conservation areas and later in no-till systems such as forestry and grazing lands since it only affects the foliage part of the sprayed plants, thus promoting intact root systems and preventing soil erosion. It also does not leach into groundwater since it is absorbed into clay particles and neutralised when it comes into contact with the soil … In the forestry industry, the use of Paraquat was seen as a best management practice because there was no need to continue with the damaging practice of hoeing or ploughing.”

The Forestry South Africa Environmental Guidelines for Commercial Plantations in South Africa (Version 4 2020, chapter 4) proposes the following approach to the preparation of firebreaks:

  1. Mowing
  2. Slashing
  3. Burning
  4. Desiccant chemicals (Paraquat) – on slopes greater than 20 per cent
  5. Manual hoeing – now discontinued
  6. Mechanical methods (ploughing) – now discontinued

The Wildland Fire Management Handbook for sub-Saharan Africa provides detailed advice on fire protection and advocates the use of ‘chemical surface sprays’ for the preparation of tracer lines i.e. Paraquat.

Paraquat may still be used by the man in the street, although a global shortage because of it being discontinued in many countries has sent prices rocketing. Is there an alternative?

Roger Poole, chairman of the Timber Industry Pesticide Working Group or TIPWG, says: “The forestry industry in collaboration with Professor Keith Little of Nelson Mandela University (NMU) has been researching and testing alternatives for the past nine years since the FSC first indicated that Paraquat would be prohibited. One alternative, pelargonic acid, has shown results similar to Paraquat as a desiccant and was heading for registration under Act 36 of 1947. Unfortunately, the manufacturer was involved with a company buy-out and the new owners changed the formulation of the original product that had been tested. Bridging trials were done to compare the new formulation to the original pelargonic acid; sadly the new formulation did not show favourable results and could not be registered. Glufosinate-ammonium is an active ingredient that is used in agriculture, classed as a partly systemic contact herbicide that is an alternative for tracer preparation - but supervision is imperative as over-application could result in it being more systemic than contact and grass root systems could be severely damaged. TIPWG has stated that Glyphosate formulations should not be used for tracer preparation as this active ingredient could result in a complete kill and thus erosion will occur, especially on steep terrain.”

Dr Scotcher adds in another factor - the human element of the spraying process: “When terrain is steep, the person spraying naturally slows down to navigate safely up or down the hillside, resulting in a higher application rate per unit area.”

Dr Gerhard Verdoorn, Operations and Stewardship Manager for CropLife SA, comments: “There is currently no herbicide with the properties of Paraquat apart from diquat which is also a bipyridinium compound with high toxicity. It is not registered for the purposes of industrial vegetation management like Paraquat is. A possibility is pelargonic acid but the dosage rates required to desiccate plants is much higher than what was originally anticipated and that makes it a very costly option. Furthermore, it is not registered in South Africa. Attempts with many other herbicides have all failed to emulate the effects of Paraquat. Glyphosate is registered for such purposes as making firebreaks but due to its systemicity, it kills plants completely which leads to terrible erosion.”

When asked about the slower progress of workers on steep slopes leading to over-application, he disagrees, saying: “Glyphosate is super-systemic and even with a low dosage (lower than label directions) it will kill plants completely, especially broad-leaved plants. Some of the tough monocotyledons like Cynodon will survive but most of the softer grass species are wiped out completely. Another issue is the problem of resistance development when sub-optimal dosages of Glyphosate are used for chemical mowing; although it is on labels of some Glyphosate-containing herbicides, it is the best catalyst for resistance development I have ever heard of and the crop sector is currently battling with Glyphosate resistance (Amaranthus palmeri, Amaranthus hybridus, Conyza bonariensis, etc).”

Is a total ban an over-reaction?
“People are very quick to point fingers at the use of pesticides but are sadly ignorant of potentially toxic products they use daily at home and, which, if used incorrectly, can be fatal,” says Roger Poole. “Everyone loves coffee, but do they know that the caffeine in coffee's LD50 is 150-200 mg/kg?” {LD50 is the amount of a substance, given all at once, that causes the death of 50% of a group of test subjects; it is a way of determining the short-term poisoning potential or acute toxicity of a substance}.

“So why has no one died from coffee? Simply put, the risk of consuming lethal quantities in your morning cup of java is not possible so the risk of poisoning is reduced. Consider household cleaning detergents, has anyone ever read the label or safety data sheet of the detergents they have in their home? Are these locked away so the uninformed cannot access them? Are certain products kept separately so that they cannot react with each other? Bleach is one of the most commonly used products found in households throughout South Africa, but did you know that if bleach and vinegar come into contact with each other their reaction can cause chlorine gas? Whatever product you are using at home or in the workplace, be it a pesticide or a detergent, they can all be toxic if used or applied incorrectly.” His message is loud and clear - use Paraquat correctly to minimise potential risks!

Is a total ban on Paraquat likely in the near future?
The Rotterdam Convention is scheduled to take place this year, although with the global COVID-19 pandemic, whether it goes ahead is uncertain. Poole says: “Paraquat is one of the many listed active ingredients for consideration to be banned worldwide and has been listed numerous times but never seems to be banned due to pressure from the large world economies. We wait in anticipation for the outcome, as we've done in the past.”

A year later on…
It’s a year since an article entitled 'Weaning the forestry industry from its paraquat reliance' by Jacqui Meyer appeared in SA Forestry magazine. According to the article, “the next step is applying for an Emergency Registration under Act 36 of 1947, which Dr Gerhard Verdoorn of CropLife SA is currently assisting TIPWG with. With CropLife’s support and the information obtained from the bridging trials, we hope to have pelargonic acid available for the 2021 summer rainfall area fire season.”

Well, that was in March 2020, and in April 2021, Dr Verdoorn was doubtful about the predictions - for this fire season at least. “I am not sure this is going to materialise… if we are able to get our hands on pelargonic acid. It is quite expensive … and I wonder if it will make the grade for the timber industry.”

In the meantime, creating tracer belts using mechanical methods such as brush-cutters and tractor-operated grass-slashers is the norm, with some landowners and companies using Glufosinate-ammonium. “It’s been very difficult, with manual clearing and a return to traditional hoeing on flat terrain,” says Simon Thomas, Operations Manager for KZN FPA. So, what will the situation be by next year’s fire season? Is a total switch to drone-spraying a feasible option? Only time will tell.

Sawdust fires and the law

Despite the fact that sawdust piles are fire hazards, they are very unlikely to spontaneously combust as a result of heat build-up as the composting process of pure sawdust is too slow. This argument was accepted by the judge in a court case in which a sawmiller was sued by a neighbouring landowner who claimed that a sawdust pile spontaneously combusted, causing a fire that damaged his plantation. DAVE DOBSON reports …

Background
This case study deals with allegations of spontaneous combustion in sawdust heaps on the Defendant’s property that resulted in a fire that devastated a neighbouring commercial pine plantation.

The Client
The client was the Defendant in this case; the owner of a property on which eucalypts were grown to supply a sawmill that processed the timber to produce pallets.

The sawdust arising from the milling operation was dumped at various localities on the property and not incinerated on account of the danger associated with this operation.

This case deals specifically with the claim by the Plaintiff that as a result of the manner in which the Defendant managed the sawdust, spontaneous combustion occurred. This lead to the wild fire that burnt the neighbouring commercial pine plantation belonging to the Plaintiff.

The Challenges
A number of challenges arose in the case but the most important one related specifically to the sawdust. In the summons it was claimed that the sawdust piles constituted a fire hazard in that:
• The Defendant had not intermittently layered the sawdust with soil.
• The Defendant had not restricted the height of the sawdust heaps so as to avert or minimise the risk of spontaneous combustion occurring in the sawdust pile.

The Plaintiff claimed that these two omissions were largely the reason for the spontaneous combustion occurring.

A third claim was that the Defendant failed to maintain an effective firebreak around the perimeter of the sawdust piles. Such a firebreak - if implemented - would have contained the fire to the sawdust pile.

The Solution
While sawdust fires are recognised as being a potential fire risk, SAFIRE Insurance Company Ltd. had at the time that this court action commenced (2012) never received a claim emanating from smouldering sawdust piles.

However there was a single incident reported to SAFIRE of a fire in a sawdust pile, but this was not the result of spontaneous combustion of the pile. This was a fire in sawdust at a sawmill on the farm Etterby in the Richmond district. This fire was extinguished by digging out the smouldering sawdust and dousing the area with water. The fire had entered the sawdust while the landowner was burning a firebreak around the sawdust pile.

Spontaneous combustion does at times occur at composting facilities when the compost heaps self-heat to temperatures high enough to ignite. In these instances no external heat source is required. In order for composting organic material to ignite very specific conditions are required. These are:
• A C:N (Carbon:Nitrogen) ratio of 20:1 to 35:1 is required. Sawdust has a C:N ratio of between 300:1 to 400:1. The result of this is that the composting process for pure sawdust will be extremely slow. (Nitrogen is required to feed the micro-organisms that are responsible for the composting process. There is simply not enough of this nutrient for them to thrive!)
• The moisture content of the compost heap must be greater than 50%. Below this percentage the composting process slows down.
• Aeration is required for rapid, efficient composting. Allowing the organic material to become anaerobic (compacted) will slow the composting process.

In the composting process temperatures in the compost stack rise and can reach 70OC to 80OC as a result of the activity of the micro-organisms breaking down the organic material. Above 80OC micro-organisms die and chemical reactions take over. This chemical heating can continue to raise the temperature of the organic material until it reaches about 150OC at which point ignition can occur. It is important to note that both the biological and chemical oxidation processes require oxygen to proliferate. Progress is extremely slow under low oxygen (anaerobic) conditions.

Back to the spontaneous combustion sawdust pile court case. In this case the Expert for the Plaintiff used the example of silage production, likening the heat build-up in silage to spontaneous combustion. From the previous discussion a number of points arise. The first is that maize used for silage is green and thus contains a high proportion of nitrogen that is required by the micro-organisms to break down this organic material. The organic material is also moist which fulfils the moisture requirement. However, silage is compacted thus resulting in anaerobic conditions. The silage will simply not burst into flame!

Further issues that mitigated against spontaneous combustion in the sawdust on the Defendant’s property were that the sawdust was spread and compacted i.e. this would have limited the oxygen available to the micro-organisms responsible for composting this organic material. The sawdust pile in question was merely one meter deep and any heat build-up would have been rapidly dissipated. Finally, had there been any combustion in the sawdust pile a source of fine ash would have marked the site of ignition. No such evidence was found.

Conclusion
Spontaneous combustion will not occur in sawdust. The primary reason being the C:N ration of this organic material. Sawdust fires will invariably be the result of fire from the outside entering the sawdust pile - as was reported in the Richmond case.

The result of the trial was a finding in favour of the Defendant. Spontaneous combustion was ruled out as the origin of the fire, and honey hunting was identified as the source. This activity had set a stump alight which later - under extreme weather conditions - ignited grass on the edge of the sawdust pile. Despite attempts by the Defendant’s team to put the fire out, it swept across the sawdust pile as well as the firebreak around the sawdust pile into a gum compartment and on into the Plaintiff’s property.

*Related article: How to calculate plantation fire damage

Like a bolt out of the blue


South Africa receives around 25 million lightning strikes a year, and Piet Retief is the ‘Lightning Capital’ of SA. While there’s not much that foresters can do to prevent lightning strikes, there’s plenty they can do to make sure they are well prepared to douse the resulting fires. GAYNOR LAWSON reports …

According to the South African Weather Service (SAWS), South Africa is the southern hemisphere’s highest risk country in terms of lightning-related deaths and injuries (following India and the USA in global terms), with an estimated 25 million strikes hitting the ground each year. Lightning causes millions of Rands’ worth of damage to property and livestock. Global warming is making matters worse, with higher temperatures, longer dry seasons and less rainfall in high-risk areas.

Direct lightning strikes in timber plantations generally do not damage more than one or two individual trees at a time, but when those trees are large, mature pines grown for saw timber, the value of the loss is quite significant – especially when there are multiple strikes over the summer storm season.

However it is the fire that results from a lightning strike that does the real damage. This is where foresters need to be well prepared to douse lightning fires quickly before they get a chance to spread.

What is lightning?
Basically, lightning is a massive, naturally-generated spark of electricity. In the early stages of a storm, air acts as an insulator between positive and negative charges present in the clouds and between clouds and the ground. If there is sufficient development of opposite charges, this insulating capacity fails, resulting in an extremely hot and fast discharge of electricity - lightning. This temporarily balances the charged areas of the atmosphere until opposite charges build up again. Lightning can heat the atmosphere to temperatures five times hotter than the sun, causing the air to quickly expand and vibrate, creating the distinctive accompanying rumbling of thunder.

Where and when does it occur?
Lightning is most likely to strike tall trees in open areas or near bodies of water, on high ground, or close to buildings with electrical wiring and plumbing. According to satellite observations, it occurs more frequently over land than over the sea, with Equatorial Africa being the most high-frequency lightning zone in the world. Locally, SAWS rates Piet Retief as the country’s lightning capital, with the highest density of strikes per square kilometre (as recorded between 2006 and 2018), and a flash density of 16,9 per square kilometre per annum. Carolina, also in Mpumalanga, is close behind with a strike density of 15,6. Generally speaking, the Eastern Escarpment and its adjacent regions have flash densities in excess of 12 flashes per km² annually. The most high-risk period for these regions is the end of October/beginning of November, with random storms occurring while conditions are still dry after winter.

How much of an issue for insurers is lightning?
Pierre Bekker, CEO of short-term insurers Safire Insurance, which has been offering cover to the forestry sector since 1987 through the Safire Crop Protection Co-operative, says: “In terms of damage to plantations, lightning has a minimal impact - it will generally take out a single tree. It’s the resultant fire that causes the damage.” Safire Crop offers plantation clients cover for ‘defined events’ including fire, lightning and explosions. “If adequate measures are in place, such as properly managed fire breaks and a fast-acting response crew, and if there isn’t too much wind with the storm and lightning, the rain that usually accompanies a storm helps curb the spread of the fire. It’s when it’s a dry storm, which is less common, that it’s a problem.”

Lightning nevertheless presents commercial and domestic insurers with a major headache. For Safire, lightning is the most expensive cause of claims - on average 18% more costly than an average burglary claim - and is the basis for over 5% of total claims paid out in the past 15 years. Last year, 10.3% of property claims from the company’s general short-term clients was for damage caused by lightning.

“It’s second on the list of causes of claims after motor vehicle accidents,” comments Bekker, “especially for farmers insured by our specialist dairy product, both in terms of severity of the incident and frequency of claims. Very seldom do we have claims for timber damaged by lightning, but much more often for cattle and other livestock or game animals, pumps and household items such as computers and TVs.”

When there’s bad weather, cattle tend to group together so that a single strike can kill several animals. Also, as farming becomes more high-tech, tractors and harvesters with their sensitive electronics are vulnerable and often have to be completely written off, resulting in high costs to the insurer. Also at risk are camera towers in plantations, largely because of their height. “It can be expensive if the fire-monitoring equipment and solar panels are taken out,” Bekker adds, “and often with lightning claims it’s hard to differentiate between actual lightning damage and damage from the power surge.”

Are there influencing factors?
Dr Ronald Heath, Director: Research & Protection at Forestry South Africa says “Lightning is similar to any point ignition. The fire intensity and rate of spread is determined by factors such as fuel load, fuel type and moisture, ambient temperature, relative humidity and geography”. People are far more dangerous than lightning; they are the most common cause of wildfires, whether intentionally or accidentally. A recent study revealed that 96% of American wildfires severe enough to threaten residential areas were caused by human actions (discarded cigarettes, rubbish left to burn unattended, arson). Also, human-caused fires are often deliberately placed for maximum impact.

“Malicious fires (arson) are frequently set in severe weather conditions and quite often at the bottom of a slope with the prevailing wind and in multiple places,” says Simon Thomas, Operations Manager & Fire Protection Officer of KZNFPA. “This will result in a very fast spread over multiple ignition sites resulting in maximum damage. Containing these types of fires is very difficult. The problem with lightning fires in the early part of the summer rainfall season (so-called dry storms), is that multiple ignitions can occur over a large area, once again making these fires difficult to contain. The difference is that often these strikes occur on high areas and not necessarily at the bottom of a slope, which results in the slower spread of these fires.”

Is there salvage value?
“Usually when a tree is directly stuck by lightning, it results in significant stem damage. Generally, the stem is not utilisable no matter the size,” says Dr Heath. In the bigger picture, a single tree does not cause financial loss.  It’s once a runaway fire develops as a result of the lightning strike and sweeps through a plantation that the loss becomes significant. Is it all bad news though? It depends. The main contributing factor is whether a salvage operation can be carried out or not. The extent of the damage and the intended use of the timber are major deciding factors. In the case of chips or pulping some timber can still be produced but at a higher cost. Burned pine needs to be harvested as quickly as possible to avoid blue staining that sets in after a fire, reducing the quality of the product being produced at the sawmills. It also depends on the current market value of the timber type, and the size and age of the tree(s). Young trees tend to suffer worse fire damage so there is unlikely to be any salvage value.

Risk management measures
Speedy response to a fire threat is vital in curtailing the spread and extent of the damage (and potential risk to the lives of responders). Manned fire towers are commonplace across the world but the human factor is a weakness: inactivity and boredom lead to sleepiness and lack of attention. The FireHawk digital fire detection system, developed locally almost 30 years ago, is popular with the larger corporate growers as well as clients in Chile, Brazil, Ghana and Malawi. But it is relatively costly. Is there an alternative for smaller growers?

“We developed Dtect as a web-based lightning detection system specifically for foresters, who face unique challenges,” says Willem Oosthuizen. Dtect was inspired by a request from Mondi for a foolproof alert system to give sufficient warning of approaching lightning to get infield personnel out of the danger zone. “It can be customised in terms of how clients receive notifications and alerts - usually directly to their cellphone - with access to a lightning map as an option.” Dtect can cross-reference between multiple sensors and is linked to the world’s largest lightning sensor network with over 1 200 sensors, ensuring the most accurate strike information available globally.

The truth?
We know the mantra: when lightning roars, go indoors. Yet around 200 South Africans die from lightning annually, mainly in rural areas when victims seek shelter under trees. Alarmingly, lightning can strike far from where rain is falling (even 16km or so away). The safest option is to retreat to a brick structure or hard-topped vehicle until you cannot see or hear lightning - an app like WeatherBug is useful for identifying how close lightning strikes really are. A roof over your head isn’t enough: sheds, pavilions, tents and covered stoeps offer no protection from lightning.

Debunking the myths
• Lightning can strike twice: the Empire State Building is hit about 25 times per year, on top and on the sides of the structure.
• You cannot be electrocuted if you touch a victim - the human body does not store electricity.
• Being inside behind closed doors is no guarantee of safety - stay away from conducting paths leading outside such as wires, plumbing, cables, metal doors and window frames.
• Lightning doesn’t always strike the highest point. It may strike the ground right next to a telephone pole or tree.
• Crouching or lying down will not make you any safer.

Remember, we live in the third most risky country in the world in terms of being killed by a lightning strike. Get inside as soon as you can.

Related article: How to calculate plantation fire damage