Sudanese Frankincense

Olibanum Tree (Genus Boswellia)

Frankincense is a small tree, between two to seven meters high, with thin bark, small flowers arranged in clusters, branched from its base, and deciduous. The resin is extracted through small incisions in the trunk and branches; The latex coagulates on contact with air and is collected by hand. They bloom in the dry season, before the leaves emerge.

These trees have a unique and distinctive appearance, with gnarled, twisted branches that look like desert bonsai.

The bark has resin ducts and a reddish-brown resinous layer. Trees begin to produce resin at approximately 8-10 years, or when the trunk reaches about 38 cm in diameter, at chest height.

There is considerable variation between species; in the shape of its leaves, flowers, fruits, branches, and size and shape of the trunk.

 

Distribution

The genus includes about 18 small to medium-sized tree species, native to the arid tropical regions of Africa, the Middle East and South Asia. The genus is distributed in 21 countries, and only some species are endemic to a single country.

It grows in arid and rocky desert mountain habitats, often on steep or rocky slopes. They can be dominant species on hills, hilltops and drier areas.

 

Ecology

Habitat destruction, insect infestation and excessive bleeding for trade are a threat to the survival of these species.

In Cameroon, Chad, Eritrea, Ethiopia, Nigeria, the Central African Republic, Sudan and Uganda, threats include agriculture, overgrazing, fires and land clearing for crop rotation. In Oman, gravel mining erodes soil, increases water evaporation and decreases nutrient availability.

Trees are subject to excessive tapping; Boswelia sacra and Boswellia in Djibouti; Boswellia papyrifera in Ethiopia and Eritrea. In Oman, where most Boswellia sacra populations are found, declines reported after several years of monitoring are attributed to inappropriate tapping methods and poor supervision during tapping, and the increased accessibility of trees contributes to their often subject to excessive bleeding and continuous harvesting throughout the year.

Inappropriate bleeding methods include cutting too deep or too long, encircling the tree. The germination rate is higher and regeneration is more appropriate in areas where bleeding is not allowed or that have not been bleeding.

Bleeding is done during the dry season, when the trees have no leaves. Bleeding depletes carbon reserves and forces the tree, forcing it to make compensations.

Populations subject to overharvesting are characterized by a lack of young specimens and seedlings. To avoid improper harvesting practices, the bleeding and harvesting method should be reviewed to protect these species.