In the heart of Ghana, a conservation experiment is rewriting our understanding of fire's relationship with forests.
Walk through the sprawling savannas of Mole National Park during the dry season, and you might encounter a seemingly destructive sight: flames licking at the dry grass, smoke rising above the acacia trees, and the crackle of burning vegetation. Yet, this apparent destruction is part of an ancient ecological cycle that has shaped these landscapes for millennia.
In Ghana's largest protected area, scientists are grappling with a complex question: how do the perennial fires that sweep through the park affect its diverse woody vegetation? The answer, emerging from years of research, reveals a story more nuanced than we might expect—a story where timing is everything, and where the difference between ecological benefit and harm lies in the subtle details of fire regimes. This research carries implications not just for conservationists but for all of us concerned about our changing planet.
Understanding the timing, frequency, and intensity of fires
How trees and shrubs respond to repeated burning
Evolutionary strategies for survival in fire-prone ecosystems
Fire has been an integral component of African savannas like Mole National Park for thousands of years. These ecosystems have evolved alongside fire, with many plant species developing sophisticated adaptations to not just survive but thrive in its presence. The Guinea savanna woodland, which characterizes much of Mole National Park, experiences a seasonal climate with a pronounced dry period when fires typically occur 4 .
These fires, rather than being universally destructive, create many environmental benefits when properly timed. They reduce grass, brush and trees that can fuel large and severe wildfires later, effectively breaking down dense undergrowth that might otherwise choke out new life. They return nutrients to the soil in the form of ash, making them available for the next generation of plants. Perhaps most importantly, they maintain the open character of savannas, preventing forests from encroaching on these unique habitats that support specialized wildlife 1 .
The fires in Mole are predominantly anthropogenic—set by humans rather than started naturally by lightning. Hunters and farmers have traditionally used fire to flush out game animals and clear debris from fields in preparation for planting. This long history of human-lit fires means that the ecosystem has co-evolved with both natural and human fire practices .
Covering 4,577 km² of fairly undisturbed Guinea savanna in northern Ghana, Mole National Park represents one of the country's most important conservation areas. As Ghana's first, largest, and most prestigious protected area, it safeguards an astonishing array of life 2 :
The Park's mission extends beyond simple protection to the sustainable management of wildlife resources, revenue generation, and supporting local socioeconomic development. Effective law enforcement and collaboration with fringe communities help protect this valuable ecosystem. Mole's ecological significance has earned it a place on UNESCO's Tentative List of World Heritage Properties, with ongoing efforts to achieve full World Heritage Site status 2 .
To understand how fires affect Mole's woody vegetation, researchers conducted a comprehensive study investigating the effects of burning timing on woody plant composition, diversity, and density. The experimental design recognized that it's not just whether an area burns that matters, but when it burns that may be most critical 1 .
The researchers established a total of thirty-six 10m x 10m plots across three different treatment types: early dry season burning (typically around November), late dry season burning (around February to April), and non-burning control plots. This design allowed for direct comparisons between different fire timing regimes and areas completely protected from fire 4 .
In each plot, scientists meticulously measured and identified all tree species, recording their diversity, density, and other characteristics. Samples were taken in March, shortly after the late burning period, to capture immediate post-fire effects. This systematic approach allowed for robust statistical analysis that could distinguish true fire effects from random variation 1 4 .
| Treatment Type | Number of Plots | Timing of Fire | Plot Size |
|---|---|---|---|
| Early Burning | 12 | November | 10m x 10m |
| Late Burning | 12 | February-April | 10m x 10m |
| Non-Burning | 12 | No fire | 10m x 10m |
The findings revealed compelling patterns about how fire timing influences Mole's woody communities. Researchers documented twenty-seven different species belonging to fourteen families across all treatments. The most common families were Combretaceae, Fabaceae, and Leguminoceae, with Vitellaria paradoxa (shea tree), Terminalia avicennioides, Combretum adenogonium, and Combretum molle emerging as the most common and abundant species across all treatments 4 .
When it came to diversity, the late burning plots recorded the lowest diversity among the three treatments. The non-burning control plots surprisingly didn't have the highest diversity—that distinction went to the early burning treatment, though these early-burned areas had the lowest tree density. This suggests that while early fires may create conditions suitable for a variety of species, they might also limit how many individual trees can survive in a given area 4 .
The non-burning plots showed higher tree density than both sets of burned plots, indicating that regardless of timing, fire reduces the number of trees in an area. However, density alone doesn't tell the whole story—the health, age distribution, and reproductive capacity of the trees are also critical factors for long-term ecosystem resilience 4 .
The trees of Mole National Park employ remarkable strategies to survive the regular fires that sweep through their habitat. Through millennia of evolutionary pressure, these species have developed sophisticated mechanisms that allow them to persist in a fire-prone environment.
The ability to regenerate new growth from protected buds after above-ground tissues have been damaged or destroyed by fire. Some species accomplish this through root reserves that fuel new growth, while others protect buds beneath thick bark or in the soil at the base of the plant 1 .
Some species have developed reproduction strategies where fire events actually trigger germination by cracking hard seed coats or providing the chemical signals needed to break dormancy. This clever adaptation means that rather than being setbacks, fires become opportunities.
The effects of fire extend below ground, creating complex interactions between burning regimes and soil properties that ultimately influence which woody species can thrive. Research from the Guinea savanna of Ghana shows that burned areas typically have higher concentrations of key nutrients like total nitrogen (N), soil organic carbon (SOC), and exchangeable calcium (Ca) compared to unburned areas .
This nutrient boost occurs because fire mineralizes organic matter, converting it into forms more readily available to plants. However, this effect varies significantly across different land use types, with a stronger positive association observed in woodlands compared to crop fields .
The East Gonja district, which includes parts of Mole National Park, recorded the highest fire density (1.0 fire km−2) in the region, reflecting the frequent burning that characterizes this area. These repeated fires create a dynamic where soil nutrients fluctuate seasonally, potentially favoring species that can quickly capitalize on post-fire nutrient pulses .
The research conducted in Mole National Park resonates far beyond its boundaries, offering insights relevant to global climate change challenges. Trees in savanna ecosystems like Mole play a crucial role in carbon sequestration—capturing atmospheric carbon and storing it in their biomass. The finding that non-burning plots had higher tree density suggests that complete fire exclusion might maximize carbon storage in the short term 4 .
However, ecosystem resilience depends on more than just tree density—diversity of biotic communities is equally important. Diverse ecosystems tend to be more stable in the face of environmental fluctuations, including those brought by climate change. The higher diversity observed in early burn plots suggests that a carefully managed fire regime might offer the best of both worlds: sufficient diversity to maintain resilience while still storing significant carbon 4 .
Sustainable land use practices emerging from this research, including the protection of trees on farms and prescribed early dry season burns, could contribute to climate change mitigation in the region. As study authors note, "Higher tree densities would enhance carbon sequestration," while appropriate fire management maintains the ecological balance necessary for long-term sustainability 4 .
The scientific evidence from Mole points strongly toward the value of prescribed early dry season burning as a management tool. Early dry season fires are typically less intense and easier to control than the raging infernos that can develop later in the dry season. These controlled burns reduce fuel loads gradually, creating firebreaks that can prevent more damaging late-season fires from sweeping across large areas 1 4 .
Less intense fires that reduce fuel loads gradually and create natural firebreaks.
Late dry season fires pose significant threats to tree populations and should be actively discouraged.
Work with local communities to shift traditional burning practices to earlier in the season.
Manage grazing pressure as it significantly impacts woody layer composition.
The research clearly indicates that late dry season fires pose a significant threat to tree species populations and should be actively discouraged through management policies and community engagement. While traditional uses of fire by local communities for hunting and field preparation are deeply rooted cultural practices, park managers might work collaboratively to shift these burning activities earlier in the season 4 .
The intricate relationship between grazing pressure and fire adds another layer of complexity to management decisions. Recent research has revealed that land use (particularly grazing pressure) is the most important predictor for woody layer composition, while climatic aridity is the primary driver for herbaceous layers. This means that managing grazing activities in and around the park may be as important as fire management for maintaining healthy woody vegetation 3 .
Conducting rigorous fire ecology research requires specialized approaches and equipment. Scientists studying fire effects in Mole National Park and similar environments rely on a suite of tools and methods to gather accurate data:
Carefully demarcated areas (typically 10m x 10m for woody vegetation studies) that allow researchers to return to the exact same location year after year to monitor changes. The systematic establishment of 12 such plots in Mole enabled consistent data collection across treatments 1 .
Tools for collecting undisturbed soil cores at standardized depths, which are then analyzed in laboratories for key properties including pH, available phosphorus, total nitrogen, soil organic carbon, and exchangeable cations .
Basic but essential equipment including diameter tapes for measuring tree girth, clinometers for height measurement, and GPS units for precise location mapping.
Satellite-derived fire count information from sources like the CSIR Meraka Institute in South Africa, which allows researchers to calculate fire densities (number of fires per square kilometer) across different regions .
Field guides and herbarium specimens for accurately identifying the numerous plant species encountered, with particular attention to species from dominant families like Combretaceae, Fabaceae, and Leguminoceae 4 .
Advanced statistical methods to distinguish true fire effects from random variation and to understand complex ecological relationships between fire regimes and vegetation responses.
The research from Mole National Park reveals a profound ecological truth: fire is not inherently good or bad—its ecological value depends on context, timing, and frequency.
The perennial fires that sweep through these savannas are neither mere disasters nor simple solutions; they are complex ecological processes that require nuanced understanding and management.
This approach respects fire's natural role in savanna ecosystems while acknowledging that human activities have already altered these landscapes in fundamental ways.
As climate change intensifies and human pressures on protected areas grow, the careful fire management approaches pioneered in Mole National Park may become increasingly valuable across the tropical savannas of West Africa and beyond. By learning to work with fire rather than simply fighting it, we can help preserve these extraordinary ecosystems for generations to come—not as frozen monuments to an unchanging ideal, but as living, evolving landscapes shaped by the elemental force of fire.
Understanding and managing fire regimes is essential for the conservation of savanna ecosystems worldwide.