Frankincense is a resin that is tapped from a dry forest tree in the Horn of Africa, the Arabian peninsula and India. The European market is dominated by frankincense from Ethiopia. But the tree populations are under threat. “We found no frankincense trees younger than half a century”, says Motuma Tolera Feyissa, who defended his PhD thesis on this subject yesterday. Frans Bongers is promotor, Ute Sass-Klaassen and Frank Sterck are co-promotors.
Anatomy of resin canals revealed
Frankincense is harvested by wounding the bark of trees and collecting the resin that is subsequently released from the wound, a process known as tapping. Tapping is carried out at several spots along the stem, using a traditional type of tool that resembles a chisel. The procedure is repeated in 8 tapping rounds during the dry season, which lasts about 8 months. But high demand means that many trees are being over-exploited and populations are at risk of dying out, threatening the livelihoods of villagers who depend on them. But help may be on hand as the results of a new study by botanists from Ethiopia and the ESG Forest Ecology and Forest Management Group, which could secure a future for the trees by revealing the anatomy of the resin secretory system. The study group was led by Motuma Tolera.
New tapping techniques
Motuma Tolera used tree ring analysis to determine the ages of two populations of frankincense trees in the north of Ethiopia. Since the 1960’s no new trees established. He also found that the frankincense is produced in a 3-D network of resin canals in the bark. “We now understand why production is higher at the end of the dry season”, Motuma says, “a cut deeper in the bark opens many more resin canals.” This creates possibilities for new tapping techniques, not one cut every 15-20 days, but a deep cut only once. This reduces damage to the tree as only one round of tapping may be sufficient to drain the year’s resin production.
Motuma is convinced that active restoration measures are urgently needed to save this species and its economic, social and ecological benefits. Exclosures (keeping grazers out) with active rehabilitation measures like enrichment planting, fire control, resting from tapping and introducing new tapping techniques that aims at minimizing the stress from tapping are options to sustainably manage the resource.