Lighting fires: A key management activity in many of the iconic protected areas of Africa

Without fires, many savannahs and the animals they support, wouldn’t exist as we know it.

Text by Elsabe van der Westhuizen, FZS Project Leader Gonarezhou National Park, Zambia

Fire has been a component of Africa’s savannah ecosystems for millennia. In traditional grazing systems the grasslands are routinely subjected to fire to stimulate new growth of nutritious grasses for livestock, to control numbers of parasitic insects and/or to manage the growth of scrub encroachment.

Without fires, many savannahs and the animals they support, wouldn’t exist as we know it and lighting them is often a key management activity in many of the iconic protected areas of Africa. In the Serengeti it is estimated that upto half of the grasslands burn annually.

Fire, under certain conditions, has been shown to have a positive impact on biodiversity in Africa’s savannahs.   In a landscape where fire forms a mosaic of burn intensity and duration– some big, some small, some hot, some cool and sometimes no fire at all – Beale et al (2018) found that these areas had up to 30% more diverse mammal communities and 40% more diverse bird communities.   It also needs to be kept in mind that fires in the savannah burn mainly dry grasses that regrow each year: the CO₂ released by fires in grasslands is reabsorbed by the growth of new grass the next year, meaning such fires are nearly carbon-neutral within a year.

Having said all this, when a savannah or wooded grassland ecosystem gets exposed to repeated annual, hot fires with little of the mosaic of intensity or spatial heterogeneity discussed above, the impacts can have a profoundly negative impact on biodiversity, vegetation structure, and cause extensive soil erosion.  With the rise in human population numbers the rate of unmanaged fires has increased, and, as much as the savannah protected areas need to be subjected to some level of fire activity, they also need to be protected from being repeatedly exposed to runaway fires in the hot dry season which burn across the landscape leaving little refuge for wildlife and vegetation. 
Therefore, in areas like Gonarezhou National Park in Zimbabwe, the fire management strategy is to strive for a mosaic of hot and cold fires on a time and spatial scale that varies from year to year.  Towards this end firebreaks, (narrow corridors that are burnt to reduce fuel load - often along roads), are created every year to give managers the opportunity to control anthropomorphic fires coming across the boundaries of the Park, or even started internally by poachers, from raging across the entire landscape.  ‘Early burns’ are also started by Park staff themselves.  These are fires started in the early dry season, when temperatures are cool, vegetation still has some moisture and the extent of the fires can be managed and their impact are therefore relatively low.  These early burns create patchy areas of burnt vegetation which can form refuges for wildlife in case of later, uncontrolled hot fires coming through, act as firebreaks and also stimulates new growth and reduces the dry fuel load.
In Gonarezhou fires are monitored through the use of satellite imagery  (https://firms.modaps.eosdis.nasa.gov/map/).  Email alerts are sent to managers when fires are detected by satellites, in the Park, or in a 15 km radius buffer zone around the Park, as well as being portrayed as real-time alerts in the Park’s Earth Ranger monitoring system, based in the Park’s central operations room.  Depending on the time of year, extent of fire and the fire history of that area, decisions are then made as to the type of response that is required.  Ranger teams in the area is put on alert, and can be called in to actively control the fire or create further breaks or ‘back-burns’ to stop the fire from progressing further.   Equipment is in place such as fire-beaters and water bowsers to assist teams in controlling fire. 
Fire monitoring and management is therefore an important component of the management responsibilities within an African protected area located in the savannah and wooded grassland biomes.  As more data comes to light with regards to the impacts, both positive and negative, of wildfires on the landscape, it is crucial for managers and ecologists to stay abreast of the information at hand, and to tailor their responses appropriately.

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