Systematising experts’ understanding of traditional burning in Portugal: a mental model approach

A mental model approach

One way to explore how perspectives on risk may vary is through the lens of mental models. According to Zaksek and Arvai (2004), how risk management information and topics are seen can vary between experts, actors from different stakeholder groups and laypeople. As such, Morgan et al. (2002) proposed the use of mental models to translate the nature and magnitude of risk, allowing a deeper understanding of how to mitigate social and environmental impacts in the future.

According to its original definition, a mental model is a ‘small-scale model’ of reality that people carry in their minds and that allows them to interpret how the world works. Mental models are used to anticipate events, reasons and underlying explanations (Craik 1943). The application of mental models in studies of communication and risk perception aims to identify specific information needs (e.g. gaps in knowledge, misunderstandings, questions, concerns about terminologies and beliefs of the population) by contrasting the mental models of specialists and laypeople concerning a specific risk (Morgan et al. 2002). Therefore, this method is applicable to different contexts and fields of study, such as: to plan potential policy changes in restoration activities (Walpole et al. 2020); to investigate the perceptions of risk and mitigation actions of employees (Stege et al. 2019); to compare the perspectives of government agencies, academic experts and suppliers on providing risk information (Aliperti et al. 2020); and to integrate different perspectives to improve the overall understanding of a system (Özesmi and Özesmi 2004). This approach has already been advocated for managing wildfire risk (Steelman and McCaffrey 2013) and employed to improve wildfire risk communication (Zaksek and Arvai 2004). However, this approach has yet to be applied to understand the challenges surrounding traditional burning.

Traditional burning in the Portuguese context

Portugal is one of the countries with the highest absolute fire danger in western-central Europe (European Environment Agency 2021) owing to the dry and warm Mediterranean summers, the prevalence of flammable vegetation types in rugged terrain, contemporary land use changes and a widespread wildland–urban interface (WUI) (Davim et al. 2021). Northern Portugal, in particular, is classified as a highly fire-prone region, first because of its vegetation and then because of anthropogenic factors (Oliveira et al. 2012; Galizia et al. 2021), including negligence.

Traditional burning involves creating a small pile of cut weeds and or any other agricultural and forest exploitation leftovers or debris, lighting it (Lewis et al. 2018), and carefully monitoring and controlling it to prevent spreading. Although traditional burning is an ancestral practice, the risks associated with this practice have grown exponentially owing to climate change (Nunes et al. 2019). Beyond the environmental component, multiple elements may drive the risks from fire use and traditional burning in the country, such as: monocultures that are highly combustible and have high economic value (e.g. pine and eucalyptus) (Canaveira 2020); rural desertification due to migratory movement to the main cities, leading to an increase in land occupation by bushes and dense forest; failure to comply with the current Portuguese legislation about mandatory phytosanitary requirements; inadequate forest management practices due to a lack of bush and forest residue collection; insufficient resources (human and material) to prevent, control and fight fires; impunity for negligence and arson; territorial fragmentation; ineffective management practices; and out-of-date landowner registries (Gomes 2006). Furthermore, while Portuguese legislation mandates that traditional burns must be communicated to municipalities, rekindles and waste of firefighting resources due to false alarms are two phenomena with a significant presence in the Portuguese forest fire management system that impact suppression resources (Pacheco et al. 2014).

The high number of rural fires caused by the negligent use of fire (DGPFR 2021) led to the creation of a formal process for traditional burning that requires farmers and landowners to follow strict guidelines set by the government, including obtaining a permit and complying with regulations regarding weather conditions, time of the year and the area in question.

Nonetheless, despite human activity and behaviour being the cause of most Portuguese rural fire ignitions in the last three decades, whether by deliberate actions, negligence, accident or carelessness, knowledge of the human causes in rural fires is still limited (Parente et al. 2018; Castro et al. 2020).

As such, the objective of the present study is to understand traditional burning and its challenges in the Portuguese context and systematise the aggregated knowledge of experts about this practice. Following a mental model approach, this study identified eight dimensions that allow a comprehensive understanding of the perspective of these experts on how traditional burning may or may not mitigate risk and manage social and environmental impacts.

Sampling and data collection

The present study involved a sample that included experts from academia (seven), industry (five), public entities (nine), and NGOs (seven), accounting for 28 interviews, as shown in Table 1.

The expert’s selection started with identifying the types of stakeholders (academia, industry, public entities and NGOs) that could provide and contribute to a thorough understanding of the context and risks related to traditional burning. Next, using a purposive sampling approach, the research team identified individuals and organisations with recognised involvement and experience in fire and forest management, considering their impact in the field (for stakeholders representing academia), the relevance of their industry or association in the national context, or their role in policy making or fire management (for stakeholders representing public entities). Individuals and organisations were then directly contacted by the research team and invited to participate in the study.

In accordance with ethical standards, the participants agreed to have their interviews recorded for further analysis. The interviews were conducted remotely (via Zoom) between June and September of 2021, and each interview took, on average, 1 h 30 min, totalling almost 39 h of recorded data. The data collected were transcribed, coded, analysed and structured following a qualitative analysis approach (Gioia et al. 2013). The NVivo software was used to support this data analysis process.

Motivations behind traditional burning

The mental model shows different motivations behind traditional burning, such as land clearing and management, property protection, and waste and residue disposal. Traditional burning is commonly used for phytosanitary purposes and as a clearing method for self-protection against rural fires. The use of traditional burns as a means to reduce fuel load is indicated by the experts as a recent motivation in the country.

Despite legislation prohibiting the burning of waste from industrial and domestic sectors in Portugal, according to the interviewed experts, the burning of civil works waste, industrial waste (e.g. textiles and wood), household trash and home appliances still occurs in some areas.

Motivations for traditional burning in rural areas include the disposal of waste from forestry operations and livestock and agricultural activity. Additionally, the experts suggested that the use of fire may also be motivated by the needs of non-resident rural property owners and emigrants who periodically visit rural areas on weekends, holidays, or vacations. During their visits, these individuals may do maintenance on their land and gardens, which can involve burning residues that have accumulated on their properties.

Overall, this burning was described as a traditional, easy and low-cost method of managing useless residues. In terms of characteristics, the experts described traditional burning as a rooted culture, a part of the routine/habit of the Portuguese population, a convenient and necessary method, and a means to keep the aesthetic look of the land that is both cheap and effective.

Risks before a traditional burn

According to the interviewed experts, the dimension of risks before a traditional burn encompasses several risk factors that were clustered into three categories in the mental model: lack of resources, negligence and lack of compliance with legal requirements. The lack of resources includes situations such as: a lack of responsiveness from fire brigades and fire management systems; inadequate risk perception and unfamiliarity with the legal norms (e.g. thinking there is a fee to request authorisation to undertake a traditional burn) or their inadequacy; or lack of willingness and/or the means to comply with the rules. The lack of one of these resources may lead to negligence or non-compliance with the legal requirements for undertaking traditional burns.

Negligence was seen as being motivated by an inadequate perception of risk on the part of traditional burning practitioners and includes examples such as: making piles that are too big; being alone while undertaking traditional burns; ignoring structural (local) and cyclical (weather conditions) risk factors; not clearing a strip of vegetation or not wetting the ground around the area of the traditional burn; not having a cell phone or internet signal for emergency communication; not having the right tools to control the fire; and lacking awareness of one’s own limited physical capacity, especially in the case of the elderly population.

In addition, the interviewees also described how inadequate risk perception by stakeholders and decision-makers can lead to the formulation of inefficient and overly restrictive public policies, which in turn can contribute to the marginalisation of fire use. Non-compliance with the legal requirements was thought to occur owing to unfamiliarity with these requirements or their inadequacy, lack of responsiveness, or lack of will. Therefore, to prevent non-compliance with legal requirements due to misunderstandings, the interviewees thought it essential to clarify and inform people about the importance of communicating traditional burns pre-emptively to prevent potential deployment of firefighting resources, which is described in the subsection on risks during a traditional burn.

Risks during a traditional burn

The experts’ descriptions related to the dimension of risks during a traditional burn encompassed four categories: bad practices, personal damage, waste of firefighting resources and undesirable/unexpected fire effects/behaviour.

The bad practices category can be seen as an extension of the negligence category that focuses on actions that take place during a traditional burn. Bad practices could refer to abandoning a traditional burn before the end, not checking the conditions of a hotspot, undertaking traditional burns in places where there is a lot of fuel accumulation, not keeping a careful watch over the site after a traditional burn, or not knowing how to interpret the signs of change in fire behaviour.

According to the interviewees, these bad practices generally increase the risks associated with the ‘undesirable/unexpected fire effects/behaviour’ category, which included: sparks thrown into the air, direct flame propagation, rekindles, uncontrolled burning and wildfires. Rural fire incidents may occur depending on a fire’s behaviour and propagation speed and some of the possible causes include small spot fires that get out of control or fires that have been successfully suppressed but not completely extinguished and rekindle.

In the traditional burning context, waste of firefighting resources stems from a lack of compliance with legal requirements, namely the use of fire without obtaining a permit. This lack of compliance leads to more inspection patrols and can cause civil protection agents (e.g. firefighters and the National Guard) to be mobilised to answer false fire alarms from neighbours. Law enforcement actions such as restrictive policies determining when landowners and farmers can legally undertake traditional burns can unintentionally drive some individuals (particularly those who do not comply with legal requirements) to abandon a traditional burn before its end.

The personal damage category includes the risks during a traditional burn that may compromise individual safety, such as personal accidents and not wearing proper protective equipment, which can cause smoke inhalation and body burns.

From the experts’ perspective, the risks before a traditional burn differ from those during a traditional burn because the former are related to the conditions that influence the decision-making process of whether to undertake a traditional burn or not.

Underlying causes of risks

The underlying causes of risks describe the indirect factors that contribute to increased rural fire risks and include rural abandonment and the absence of active management, which are both drivers of fuel accumulation. The rural population was seen to be sensitive to the possible effects of climate change on the security of their homes and dependence on resources for subsistence agriculture. Rural communities’ challenges were seen as intensified by poor access to markets and public services, lack of economic diversification and reduced labour opportunities, and insufficient access to information and knowledge. A lack of profitability, security and comfort can lead to migration and decreased agricultural activities, leaving only the aging population behind. Furthermore, structural problems in land use planning (e.g. fragmentation of properties) and a lack of opportunities for educated youth to productively employ their skills evoke their disinterest in rural activities (qualified or not).

In parallel, the experts believe that the absence of active land management is the result of the decrease in livestock activity, agricultural occupation and available labour, increased labour costs, and land ownership uncertainty due to the lack of clarity in defining land boundaries and property rights. A practical example cited by one of the interviewees, which concerns the socio-environmental transformation and increased risks of traditional burning, is the increasingly small window of opportunity for this practice. Despite the underlying causes of risk focusing on social transformation, the environmental challenges are addressed in the exogenous elements and factors subsection.

Alternative solutions

The alternative solutions dimension describes less risky alternatives to traditional burning such as crushing waste, processing it into pellets on site, leaving it in the soil for further decomposition or incorporating it into the soil to improve its structure and quality, collecting/storing it to use as biomass, composting it to produce organic fertiliser, and using it for energy production at small or large scales.

Micro biomass power plants are a relevant solution to reduce fuel load and fire risk in small rural communities, as the biomass available can be used for heating public spaces (e.g. schools, health centres and swimming pools) and private homes. However, according to the experts, the widespread use of biomass would potentially require incentives from public policies (e.g. encouraging renewable energy sources, the active management of fuels and the use of biomass for home heating).

Alternatives like crushing, on-site pellet processing, local micro power plants for heat production, or biomass plants are dependent on a large investment and entail high machine operating costs. Additionally, the logistics surrounding the collection/storage of the material to use for biomass and energy production make these alternatives inconvenient and inefficient. For example, transporting the material to feed the combustors is a challenging task. Thus, residues could be made more compact through densification processes, such as transforming them into solid fuels like pellets or briquettes. Still, once again, these solutions require large investments that may make them financially and economically unfeasible.

According to an interviewee, some municipalities provide a service of centralised sites with containers for collecting agroforestry residues. Still, he believes the mere existence of centralised sites would not be enough to motivate and engage citizens to use the service offered, owing the additional effort of transport and disposal into the containers.

On the opposite side, solutions like leaving the material in the soil for further decomposition or incorporating it into the soil to improve its structure and quality, storing it for heat production at home, and composting it to produce organic fertiliser are usually oriented at small-scale operations. In order to turn these solutions into large-scale operations that are commercially feasible, local authorities could incentivise the establishment of cooperatives.

Exogenous elements and factors

Some exogenous elements and factors can lead to an increase in the risks related to fire behaviour and propagation speed. On one hand, some exogenous factors depend on human decisions and activity, such as controlling the existing fuel load, avoiding the selection and growth of flammable vegetation on the land (fuel models), and choosing the appropriate period to undertake traditional burns according to the last rain. On the other hand, exogenous factors such as cumulative temperature, air and fuel humidity, orography, and wind speed and direction cannot be controlled by humans and can impact fire behaviour and propagation speed.

According to the experts, evaluating the risks of a traditional burn should involve an analysis of not only temperature and humidity, but also of other exogenous factors like orography, wind speed and direction, existing fuel load and flammability. As such, the loss of know-how related to traditional burning in consequence of the disinterest of young people in rural activities has been a matter of concern for experts.

Climate change and landscape transformation are critical environmental factors that must be considered and used to shape new patterns of risk. In other words, the exogenous conditions that guided someone’s decision to undertake a traditional burn in the past (e.g. a cloudy day) may not ensure safety nowadays. Thus, the demand for updated risk assessment owing to climate change is a challenging issue for future land management and rural fire risk prevention. As the climate continues to change, traditional approaches to risk assessment and management may no longer be adequate. It is imperative to adapt and update risk assessment frameworks including the evolving environmental conditions, impacts of climate change on fire behaviour, land management practices and societal vulnerabilities.

Activities leading to a successful traditional burn

The activities leading to a successful traditional burn dimension focuses on determinant actions in the risk mitigation process, such as adequate risk perception, technical support and monitoring, sensitisation and education on the use of fire, including appropriate risk communication strategies. Communicating the risks associated with traditional burning is essential, considering that people were seen to have different levels of information and experience with the use of fire.

The experts highlighted that risk mitigation actions (e.g. monitoring and sensitisation) must be intensified during the summer and spring seasons, when the population increases in rural areas. During this period, urban citizens visit rural areas for tourism and recreational purposes, and non-resident rural owners and emigrants return to their rural properties on weekends, holidays, or vacations, using the opportunity to tidy their land and gardens. Furthermore, more technical support and monitoring are needed to better support traditional burning practitioners.

According to the expert community, sensitisation efforts and technical support actions must be aimed at supporting traditional burning and incentivising alternative solutions. In other words, the experts argued that guidelines and inspections should facilitate and support the traditional burning process, offering useful information so that it can be performed safely. They also advocated raising awareness and providing education on the use of alternative solutions as a way to decrease the number of ignitions. The experts believe that, with more support, it is possible to incorporate a mindset that includes alternative solutions into the behaviour of future generations.

Potential impacts

Many of the aforementioned risks before and during a traditional burn may lead to fire getting out of control and escaping, resulting in rural fires and, consequently, varied impacts. Therefore, the expert mental model included 12 impact variables distributed across social, environmental and economic categories.

The impacts pointed out by the experts were mostly negative, except for fuel load reduction. For some experts, traditional burning contributes to fuel load reduction, thus mitigating rural fire risk. In contrast, other experts did not identify any positive impacts brought by traditional burning.

In terms of ecological impacts, the mental models mentioned the spread of invasive species as an example. Regarding social impacts, some of the examples mentioned were mental health problems (permanent or short-term), physical injuries, respiratory, cardiac and oncological diseases, and death. Crime and the marginalisation of the use of fire were cited as unintended consequences of the implementation of more rigorous inspections and coercion/enforcement actions. Indeed, although the implementation of stricter penalties and sanctions for violating fire regulations may deter some individuals from using fire, these measures can lead to behaviours such as concealing the use of fire, selecting unsafe burning conditions, or failing to properly manage fires until completion.

Lastly, examples of economic impacts include administrative offences leading to fines and the reduction of available resources if authorities are mobilised to false fire alarms. For example, the latter would mean that firefighters and other authorities are not able to handle other rural fire events, and there has to be an investment in air resources that could otherwise be avoided.