The use of pesticides in South African timber plantations – are we on the right track?

The view of David Everard based on over 20 years of experience as Environmental Manager for Sappi Forests. 29 May 2020

In these challenging times of the Covid-19 pandemic where a fundamental change in the way we live and do things is inevitable, it is a time when many of us, I think, have pondered the sustainability of current human lifestyles. As an environmental practitioner and a nature lover, it is something I have thought about and investigated quite a lot. I particularly like the “planetary boundary” framework or approach promoted by the Stockholm Resilience Centre where they identify nine planetary boundaries within which humanity can continue to thrive and develop.

The nine planetary boundaries – Stockholm Resilience Centre

One of the boundaries is Chemical pollution and the release of novel entities. In the words of the Centre, “emissions of toxic and long-lived substances such as synthetic organic pollutants, heavy metal compounds and radioactive materials represent some of the key human-driven changes to the planetary environment. These compounds can have potentially irreversible effects on living organisms and on the physical environment (by affecting atmospheric processes and climate). Even when the uptake and bioaccumulation of chemical pollution are at sub-lethal levels for organisms, the effects of reduced fertility and the potential of permanent genetic damage can have severe effects on ecosystems far removed from the source of the pollution. For example, persistent organic compounds have caused dramatic reductions in bird populations and impaired reproduction and development in marine mammals. There are many examples of additive and synergic effects from these compounds, but these are still poorly understood scientifically. At present, we are unable to quantify a single chemical pollution boundary, although the risk of crossing Earth system thresholds is considered sufficiently well-defined for it to be included in the list as a priority for precautionary action and further research.”

So, to cut a long story short, I strongly believe that we, as the plantation timber industry in South Africa must make use of pesticides in a responsible and carefully considered manner but, are we on the right track?

Twenty years ago, like today, the biggest use of pesticides was for herbicides to control alien invasive plants across plantation estates and other weeds competing with tree crops. However, before certification, there were few constraints on which pesticide and the quantities that could be used. With the advent of FSC certification, certain highly hazardous chemicals became prohibited and managers were required to record the quantities of pesticides used to reduce these. The problem was that the FSC approach was rule-based to which the industry responded with arguments and more and more justification for the use of pesticides. If records were kept and the requirements of the FSC forest management standard were met, the industry continued to use pesticides, probably with increased volumes. Granted, the alien invasive plant problem has continued to grow, so there is probably some justification for the increased use of pesticides. I do, however, think the industry was slow to consider and research alternative control measures for alien invasive plants and some insect pests except the use of biocontrol which was getting much attention in those days. If and why biocontrol for alien plants has largely been abandoned in South Africa is a subject for another debate, but generally, our only response to the control of alien invasive plants is the use of herbicides. The old FSC approach was not working, the problem was getting worse and the use of pesticides was growing.

Last year, the FSC published a new policy on the use of pesticides in certified forests, which is far more risk-based and has required the industry to do more research, be more analytical in decisions around pest control and manage the risks and the negative impacts of pesticide use. All good things, but will this lead to a less toxic world with less threat to our crops and ecosystems from weeds, pests and diseases?

The answer to this question revolves around several factors:

The level at which policies and procedures are developed and how these influence the actual application of pesticides on the ground. Currently, the industry is relying on TIPWG to create templates for integrated pesticide use documents, conduct Environmental and Social Risk Assessments (ESRA’s) for active ingredients and the development of operational procedures. These are all good things, as it saves resources, ensures consistency and ensures robustness, but we as an industry will only be on the right track if these policies and procedures are used by foresters and farmers when deciding whether to use a pesticide, what to use and how to use them. We need the manager to be empowered to make decisions based on good information, and not to mechanically follow a recipe without thought.

The conditions for use and requirements attached to pesticide use need to be clear, rational and easily understood. The implementation of the revised FSC policy will only be effective if the requirements can be met practically and they make sense, i.e. lead to the most appropriate choice of control method and eventually a reduction in pesticide use. On the subject or the FSC pesticide policy, I do have a concern that it is a hybrid system, using hazard (toxicity) and as well as risk and wonder if, for instance, the banning of paraquat will lead to the best-balanced outcome. I fear the environmental impact of permanently damaged vegetation on tracer belts may be a greater risk than the health of people, especially as new application technologies are developed, such as the use of drones.

The proficiency of the decision-makers (managers) and the people handling and applying the pesticide is also particularly important. We are a big industry, covering a large area, with people speaking various languages, with different levels of education and with different needs. Communicating with and training a large number and variety of people will be a huge task, but it is necessary if we are to succeed in reducing the use and impacts of pesticides.

Lastly, more research is required, especially a revitalising of biocontrol of alien invasive plants and other non-pesticide control methods. I strongly believe we need to be more ecological in our view of alien invasive plants and use natural processes to get a more stable environment.

Are we on the right track – yes, but there remains much to do, and it is for this reason that TIPWG remains vital to the industry and needs all the support it can get!

/ Pesticide interest piece