Boswellia tree species – the frankincense resin-bearing trees that are the main source of livelihood in Africa’s drylands – could be driven to extinction in the near future due to the impacts of climate change.
One of the world’s oldest commercial commodities, frankincense is sought after by makers of perfumes, natural medicines, and essential oils – and it’s also widely used by the Catholic Church as incense in thuribles.
Over the years, demand for frankincense has been rising steadily, putting pressure on Boswellia tree species, which only grow in arid environments and marginal lands where other tree species cannot easily grow – and this rare tree species is pivotal in regulating microclimate.
But now a new study has sounded an alarm, saying that Boswellia trees – found mainly in the Horn of Africa – are rapidly decreasing. And this trend is predicted to continue for years to come.
“This drop in occurrence probability and restriction in distribution can be explained by precipitation changes expected to occur in Africa,” says a new study by researchers Elias Cherenet Weldemariam of Ethiopia’s Haramaya University and Luíz Fernando Esser of the Federal University of Rio Grande in Brazil.
The future of Boswellia tree species is particularly threatened because they are adapted to dry environments and yet the last Intergovernmental Panel on Climate Change (IPCC) scenarios predict a significant increase in precipitation in the Horn of Africa region.
Boswellia tree species and other could disappear because of loss of ecosystems
The latest IPCC report warned that the extreme weather events such as prolonged droughts and recurring floods are likely to lead to species extinction and loss of ecosystems – resulting in reduction in economic output and increased human vulnerability.
The new study, which is titled Climate changes could jeopardise a main source of livelihood in Africa’s drylands, was recently published in Journal for Nature Conservation.
The researchers said they used ecological niche modeling to find critical site where the Boswellia species may be driven to extinction in the coming years. The study included all the five Boswellia tree sub-species: Boswellia dalzietlii, Boswellia microphylla, Boswellia neglecta, Boswellia papyrifera and Boswellia rivae.
Currently, Boswellia dalzietlii is the only sub-species with distribution outside eastern Africa – in Nigeria – and the only one that indicates an increase in area of occurrence, according to the study.
“Other species, which are all centered in East Africa, have a similar pattern of loss of occurrence probability long scenarios that leads them to constrain their distributions. Eastern species will face area decrease, with a maximum of 23 per cent decrease,” the researchers said, adding that the Boswellia neglecta sub-species, which is currently present in the northern Ethiopia and Tanzania, will be specifically affected.
Previous studies have shown that there is an overall decrease in land that is favourable for Boswellia tree species due to rapid population growth, which has in recent years led to significant increase in the demand for large scale cropland.
Aside from habitat loss, the researchers also found that the Boswellia trees are threatened by lack of regeneration and overexploitation.
“In addition,” say Weldemariam and Esser, “continuous tapping without a proper resting period and tapping young trees remain the main factors to population decay. Furthermore, the overexploitation of young trees causes a lack of young shoots in many Boswellia dominated forests, compromising regeneration.”
Boswellia are found almost exclusively in regions with a harsh, arid climate that are plagued by conflict and poverty, and selling the resin may be the only source of income for many people in these areas, leading to overtapping. the villager trying to scrape out a living from frankincense trees
The long-term solution to shortages, Boersma says, is to revert to old, more sustainable ways of harvesting frankincense. “When you grow a tree, I think it takes 25 years before it starts supplying its first incense.
Gum, resin and frankincense products from Boswellia species improve economic and livelihood of communities in many dryland regions of Africa, allied with regulation of ecosystem functions. To collect frankincense, harvesters make incisions into the trunks and scrape out the oozing sap, which hardens into frankincense resin.
“The west coast of Lake Victoria Uganda, Rwanda, Burundi and Tanzania and the areas surrounding Kilimanjaro, in Kenya and Tanzania, are sites with consistent high probability of occurrence across scenarios.
“Future investments in restoration and strategies to promote sustainable extraction of resources may be key to sustain populations and Boswellia dominated forests in many parts of the African continent,” the study says.
The most effective ways to conserve and maintain populations in their natural distribution are the use of an effective protected areas network, allied with forest management strategies and clear policy direction. Main actions for Boswellia species are the promotion of regeneration and survival of the tree species through: area closure, reduced tapping of young trees, respecting rest period and promoting natural regeneration.
They suggest that eastern Africa – where most Boswellia trees can be found – is one particular region on the continent that could benefit from them, and promote conservation efforts for this unique tree species to thrive.
