By David Okul
30 Sept 2020
Rangeland fires are ubiquitous in the African savannas, especially in the dry season. Livestock owners and range managers would start fires to promote the growth of good grass. In some cases, the fire could start from lightning or accidents. Regardless, the fires have been part of the African savannas for generations. For a long time, the fires have been considered as essential for the integrity of the savanna system. The question is whether the fires are a necessary management practice in the face of climate change and other environmental problems of the 21st century.
Ecological importance of the Rangeland fires in Africa
Many people believe that wildfires are vital for the survival of the savannas. They argue that the fires do little to destroy the biological community, hence they do not threaten biodivesity. The major benefits of the forest fires to the ecology are cited as:
- Fires provide a feast for animals. Species like birds come to devour grasses, mice, lizards, or even snakes killed or driven out by the fires.
- Some animals and plants rely on the fires for their survival. For instance, some trees will require fire to break seed dormancy. Also, some birds, e.g. Temminck Courser, only nests in recently burned grasslands.
- Underground holes and crevices provide a hiding place for small creatures. Larger animals can usually run from the fire
- The fire would burn dry stem and leaves of grasses and some trees. However, the roots remain unharmed and would sprout when moisture is available. This sprouting nature of the grasses is the main reason why pastoralists set grasslands on fire in the dry season. Wildlife also benefit from the emerging nutritious grass
- The burnt shrubs can also survive on starch reserves until favorable conditions come up.
- Fires are also set up to control the emergence of thorny bush and the widespread of ticks and other parasites to livestock
Professionals assert that well-controlled fires are an effective tool to manipulate vegetation composition, structure, and fuel loads on rangelands (and other wildland ecosystems).
Because of the aforementioned reasons, fire is often encouraged in the management of rangelands across Africa. Moreover, many managers believe that frequent burning of rangelands is good because it is a way of preventing big catastrophic fires. After all, ignoring the burning of grass leads to a build-up of fuel.
All that glitters is not gold
The use of fire as a management tool requires it to be applied at the correct frequency, intensity, and scale. We think that most wildfires today are not effective in management. Rangeland fires may have worked to shape African savannas in the past, but is it still a viable management tool? Here are a few points why we think that wildfires shouldn’t be encouraged
The effects of rangeland fires on soils
Soils are among the most vital of natural resources. After all, they support most of the terrestrial wildlife habitats and the agricultural systems that humans depend on for food. However, there is a consensus that burning often harms soil minerals. A conference paper claims that burned areas have between 1071 and 1420 grams per meter square less carbon compared to unburned areas. Moreover, burned soils have lesser nitrogen but higher calcium. In the advent of climate change, managers should rethink the effect of burning rangelands as a management practice because of its impacts on soil organic carbon.
EXCLUSIVE STORY: The Tsavo Conservation area that consists of the Tsavo East and Tsavo West National Park has come under threat in the past months from separate fire incidences that have destroyed thousands of acres of vegetation.https://t.co/2R6Ajxjb8p pic.twitter.com/MeHwi4tqmX
— Kenyans.co.ke (@Kenyans) August 1, 2020
Fire caused damages to properties
Uncontrolled fires in rangelands can result in losses in property. These could include things like cars, houses, or even livestock. Rangelands in Africa are also the locations for lodges and hotels.
Potential impacts of rangeland fires on biodiversity
Given that some plants and animals benefit from wildfire, other species are adversely affected by it. For instance, the fires could kill small animals like rodents and reptiles. Not to mention, fires could also kill and prevent the growth of young tree seedlings. Although many trees in African rangelands are resistant to fire, young seedlings may not withstand the heat. Moreover, grassland fires could sometime encroach into woodlands or forested areas.
The carbon equation
Its obvious, burning grass does emit carbon into the atmosphere. However, it can be argued that the grass could have dried and rotted anyways, still emitting the carbon. Some scientists argue that the fires in the savannas are almost always carbon neutral. This argument emerges from the observation that grass burnt usually regrows after one year and absorbs the equivalent of carbon emitted. Without a doubt, the fires have a negative impact on soil carbon stock and the regeneration of woody plant matter, which could store more carbon.
Fires have been an important management tool in the African rangelands. However, challenges such as habitat fragmentation, overgrazing, biodiversity loss, and climate change should make managers reconsider the effectiveness of fires. Personally, I think in the big picture fires are more detrimental than useful in the African rangelands.
David Okul is an environmental management professional with over 10 years experience on donor projects, conservation, forestry, ecotourism, and community-based natural resources management. When not working on active environmental management projects, I spend my time writing for Silvica on a variety of topics. The views on this blog post are personal.
