Thabo Mohlala
Forests play a critical role in helping to limit the negative impact of climate change. This is one of the key findings of the study conducted by a team of international scientists from South Africa and some European universities.
The team focused on the so-called “Sacred Forest”* in Togo, West Africa, where they discovered that the forest “play a vital role in the storage of carbon and could help to mitigate the effects of climate change”.
The study will bolster global efforts and campaigns spearheaded by environmentalists and climate change activists in encouraging communities to plant trees in their localities as well as preserve existing natural forests which are considered “the lungs of the planet”.
According to the study “it is important to preserve the soil in these forests, which cover several hundred square kilometres, not just for carbon storage, but also for biodiversity and ecosystem functioning”.
The intention of the researchers was to get a sense of the variations in soil properties and the process of carbon formation in the soil under these highly biodiverse “Sacred Forests”. These are used for religious purposes and believed to be inhabited and protected by gods, totem animals or ancestors. They then analysed the structure, components and features of the soil as well as the minerals that it contains.
Dr Michele Francis, one of the researchers involved in the study, said: “Our study showed that soils in these forests preserve at least 8.64 tonnes of inorganic carbon per hectare. This carbon is derived directly from the CO2 in the air of the soil. In real terms, we are talking about an area the size of a rugby field that permanently removed as much CO2 as is released by a power station burning 15.8 tonnes of coal.”
Francis, who is based at department of Soil Science at Stellenbosch University, collaborated with Dr Hafeez Rehman (Norwegian University of Life Sciences, Norway), and Profs Rosa Poch (University of Lleida, Catalonia, Spain), and Fabio Scarciglia (University of Calabria, Italy).
She further explained that “soil inorganic carbon is an important carbon sink because the carbon is permanently locked away in mineral form, unlike carbon derived from soil organic matter such as leaf litter and humus”. She said the organic matter decomposes and releases the carbon back to the atmosphere as CO2 again, adding that “unless there is an intermediary step which is able to capture and store the carbon permanently – as in the sacred forest soils”.
Due to the dry nature of the area, said Francis, the mineral form of this inorganic carbon remains in the soil and does not dissolve. This will be an even more important form of carbon storage in the future, since the long-term trend is to an increasing severity of the aridity in Togo.
She said there is a high potential for development of the soils of the area in terms of agriculture and agroforestry and for potential carbon sequestration relevant to global change policies.
“Understanding these natural processes is fundamental for the implementation of soil management practices leading to carbon sequestration and improvement of soil quality status in the region, and possibly in other countries with similar climates, vegetation, and land use/land cover histories,” she added.
This is particularly important in areas where these forests are becoming rarer and more fragmented because of population growth, expansion of buildings, construction of roads, and erosion of traditional religious beliefs, said Francis, adding that their findings would be of interest to people in agriculture, ecology, biology, forestry and earth sciences.
The findings of their study were recently published in the open-access journal Catena.
*The sacred forest is located in the Centre de Formation Rurale de Tami (CFRT), which trains local farmers. Much of the farming techniques rely on adding organic matter back to the depleted soils, for example by adding leaf litter, which mirrors the processes in the sacred forests. It is run by the La Salle brothers.
