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BRITISH ECOLOGICAL SOCIETY PRESS RELEASE

12 December 2006

Frankincense trees overexploited for Christmas scent

Current rates of tapping frankincense - which according to the Bible was given to the baby Jesus by the three wise men at Christmas and which will feature in thousands of Nativity plays in coming days - are endangering the fragrant resin's sustained production, ecologists have warned. Writing in the December issue of Journal of Applied Ecology, ecologists from the Netherlands and Eritrea say that over tapping the trees results in them producing fewer, less viable seeds.

Frankincense is an aromatic hardened wood resin obtained by tapping Boswellia trees. For thousands of years, frankincense has been hugely important both socially and economically as an ingredient in incense and perfumes. But, say the ecologists, its production in the Horn of Africa is declining because Boswellia woodlands are failing to regenerate.

The ecologists hypothesised that poor regeneration was due to the fact that intensive tapping meant that the trees were diverting too much carbohydrate into resin, at the expense of reproductive organs, such as flowers, fruit and seeds. Working in south-western Eritrea, they tested the hypothesis by looking at how many seeds intensively tapped trees produced, and their germination rates, compared with untapped trees.

According to one of the authors of the study, Professor Frans Bongers of Wageningen University: “This study strongly suggests that there is competition between investment of carbohydrates in sexual reproductive structures and synthesis of frankincense in Boswellia papyrifera. At all study sites, trees subject to experimental tapping produced fewer flowers, fruits and seeds than trees that were exempt from tapping. Furthermore, tapped trees produced smaller fruits with seeds of lower weight and reduced vitality than non-tapped trees.”

Based on their findings the authors say that, for production to be sustainable, the way that frankincense is tapped needs to be changed. “In order to control the decline in fruit and seed production, less intensive tapping procedures should be developed. As our results show that six tapping points per tree are already having a negative impact, we suggest reducing the number of tapping points. New tapping regimes should include rest periods when there is no resin harvesting to allow the trees to recover,” they say.

Although the impact of tapping trees for other crops, such as latex and pine resin, has been studied in plantations, this is the first study to show quantitatively the fragile relationship between the extraction of wood exudates and tree regeneration in natural populations.

- ends -

Notes for editors

1. Toon Rijkers et al (2006). The effect of tapping for frankincense on sexual reproduction in Boswellia papyrifera. Journal of Applied Ecology, 43(6), 1188-1195. Copies are available at www.blackwellpublishing.com/jpe.

2. For further information, please contact Professor Frans Bongers, Wageningen University, tel: + 31 317 478029, email: frans.bongers@wur.nl or Becky Allen, BES Press Officer, tel: +44 (0)1223 570016, mob: + 44 (0)7949 804317, email: beckyallen@ntlworld.com.

3. At least five species of Boswellia are currently exploited for frankincense. Boswellia papyrifera is a small deciduous tree that grows in a savanna belt stretching from northern Nigeria eastwards to the highlands of Eritrea and Ethiopia. In Eritrea, it grows under semi-arid conditions in shallow soils on rocky slopes. Despite its economic importance, B. papyrifera is a threatened species in Eritrea where Boswellia woodlands are being destroyed for agricultural land.

4. The Journal of Applied Ecology is published by Blackwell Publishing for the British Ecological Society. Contents lists are available at www.blackwellpublishing.com/jpe.

5. The British Ecological Society is a learned society, a registered charity and a company limited by guarantee. Established in 1913 by academics to promote and foster the study of ecology in its widest sense, the Society has 4,000 members in the UK and abroad. Further information is available at www.britishecologicalsociety.org.

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