Wildfires driven by combination of “climate, fuel load, and human activities,” study finds

Fires also pose significant threats to human lives, health, and livelihoods, as evidenced by the catastrophic fire in South Africa’s Garden Route region. Picture: File Picture

Fires also pose significant threats to human lives, health, and livelihoods, as evidenced by the catastrophic fire in South Africa’s Garden Route region. Picture: File Picture

Published Aug 5, 2024

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A recent paper by wildfire researcher and environmental scientist Daniel Boshoff, published in the Jàmbá - Journal of Disaster Risk Studies, has introduced a groundbreaking framework for understanding fire regimes.

This comprehensive approach seeks to elucidate the complex factors driving wildfire occurrences, providing crucial insights for disaster risk planning and fire management strategies.

Wildfires have naturally occurred across the Earth's land surface long before human influence, playing an essential role in ecosystem dynamics. According to Boshoff, fires clear plant debris, promote the regeneration of specific plant species, and facilitate processes like resprouting, germination, and flowering.

However, fires also pose significant threats to human lives, health, and livelihoods, as evidenced by the catastrophic fire in South Africa’s Garden Route region, which resulted in seven deaths and approximately R1.9 billion in property damages.

The frequency and severity of wildfires have increased globally, with notable incidents in Canada, Greece, Hawaii, and the Canary Islands in 2023. NASA attributes this trend largely to climate change, though the conditions favouring fire spread are multifaceted.

"Understanding the behaviour, spread, and occurrence of fire is a complex endeavour," Boshoff notes, underscoring the need for a detailed examination of fire regimes.

Definitions of fire regimes vary, but they generally describe the role of fire in ecosystems over specific spatial and temporal scales. Fire regimes are driven by a combination of climate, fuel load, and human activities.

Recently, climate change has been implicated in the increasing severity and frequency of fires.

However, Boshoff argues that understanding fire regimes requires looking beyond these generalisations to focus on specific characteristics and drivers, which can vary significantly across different ecosystems.

Human activities, including fire management practices, land use changes, and the introduction of invasive species, have significantly influenced contemporary fire regimes.

As Boshoff highlights, "Human actions have become the dominant driver of fire regimes, altering natural fire occurrences through practices like deforestation, habitat fragmentation, and fire suppression policies."

The proposed framework integrates often overlooked variables such as soil moisture, soil type, and herbivory, offering a more comprehensive understanding of fire regimes. This biogeographical perspective addresses the limitations of previous models by incorporating the Earth's four spheres—biosphere, atmosphere, hydrosphere, and lithosphere—emphasising their interconnected roles in fire dynamics.

The framework also leverages advanced geographical processing tools like remote sensing and geographic information systems (GIS), facilitating a deeper analysis of fire patterns and aiding in the development of effective fire management strategies.

By incorporating a wide range of physical and human factors, Boshoff's approach aims to enhance our ability to predict and mitigate the impacts of wildfires. This innovative perspective on fire regimes underscores the importance of a multifaceted approach to wildfire management.

As climate change continues to alter fire dynamics globally, integrating diverse variables and adopting a biogeographical perspective will be crucial for developing resilient and adaptive fire management policies.

"Wildfires are interesting phenomena and not the straightforward 'oh, someone threw a cigarette next to the road.' There are several factors which have to align perfectly for wildfires to occur and now we are in an interesting time where the influence of human activities have become so prominent in the environment," he concluded.

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