Conservation Assessment and Chemistry of Boswellia ogadensis, a Critically Endangered Frankincense Tree

Boswellia ogadensis is a critically endangered species of frankincense tree, restricted to a small area of the Shabelle river valley in southern Ethiopia. It has only been recorded from two botanical collecting trips, in 1972 and 2006, with no indication of the abundance, threats, or population status of the trees, and it was listed on the IUCN Red List of Endangered Species as Critically Endangered in 2018. More recent expeditions, in 2019 and 2021, were not able to locate the species, raising concerns about its continued survival. We carried out a field survey in June 2022 to re-locate the species, assess the threat level it is facing, and collect samples of resin for analysis. This survey revealed that B. ogadensis is present in more locations than previously recorded, and is more abundant than thought. While it is facing multiple threats, including grazing, cutting for firewood, and insect attacks, these threats vary geographically, and there are populations that appear to be healthy and regenerating well. While more research is needed, the current survey indicates that downlisting to Endangered status may be appropriate. Samples of resin were also collected and analyzed using gas chromatographic techniques, revealing that while the essential oil profile is similar to that of other Boswellia species (dominated by alpha-thujene, alpha-pinene, p-cymene, and terpenin-4-ol), there are chemical markers that can distinguish it from other sympatric Boswellia species, indicating the potential for this to be used as a tool to monitor whether B. ogadensis is being harvested alongside other more common Boswellia species.

Automated summary

Boswellia ogadensis is a critically endangered species of frankincense tree found in southern Ethiopia. Recent surveys have shown that it is more widespread and abundant than previously thought, with some populations appearing to be healthy and regenerating well. While facing various threats, this species has the potential to be downlisted to Endangered status. Chemical analysis of resin samples revealed that there are markers that can distinguish B. ogadensis from other sympatric Boswellia species, making it a potential tool for monitoring its conservation status.