Frankincense—that aromatic staple of the original Christmas story—could soon be "doomed" to near-extinction, according to research published December 21 in the Journal of Applied Ecology.

Frankincense is an aromatic resin used in perfumes and incense. It comes from trees of the Boswellia genus, which grow mostly in the Horn of Africa and Arabian Peninsula. The International Union for Conservation of Nature and Natural Resources includes 10 Boswellia species on the Red List of Threatened Species, eight of which are listed as vulnerable to extinction.

But vulnerable may just be the beginning. The researchers found that Boswellia trees could decline by 90 percent in the next 50 years due to high mortality rates for seedlings, mostly driven by cattle grazing and increased fire frequency, which is likely a side effect of greater cattle populations. Fires also appear to have made the adult trees more vulnerable to attacks by long-horn beetles (Idactus spinipennis), which burrow into the trees to lay their eggs, often killing them in the process. In a shorter time frame, the researchers say that frankincense production could be halved in the next 15 years.

"Current management of Boswellia populations is clearly unsustainable," lead author Frans Bongers said in a prepared statement. "Our models show that within 50 years populations of Boswellia will be decimated and the declining populations mean frankincense production is doomed. This is a rather alarming message for the incense industry and conservation organizations."

Bongers and his team studied 12 populations of Boswellia papyrifera trees in Ethiopia, six of which were routinely tapped for their resin. The two-year study tracked 4,370 trees and an additional 2,228 seedlings, studying their growth rates, fecundity and reproduction rates. One of the most troubling observations of the study was the virtual lack of saplings and young trees, indicating that almost all seedlings perish from fire or grazing by farm animals. The adult trees also had a 6 to 7 percent mortality rate, caused both by fire and beetles.

The paper's authors recommend protecting some Boswellia populations from fire and grazing, along with increasing regeneration by growing saplings in nurseries and then transferring them into natural populations.

This is Bongers's latest study of frankincense. In 2006 a previous study—also published in the Journal of Applied Ecology—found that overexploitation of frankincense resin from Boswellia trees was causing them to produce one third as many seeds as untapped trees. Bongers and his co-authors warned then that this—along with the clearing of natural Boswellia forests for agriculture—threatened the trees' ability to reproduce. "There's not a shortage of frankincense, but there's no regeneration of the forests. There are no young trees anymore," Bongers said at the time. This latest study finds that overexploitation isn't the full story and that broader land-use issues are further hurting the trees' long-term chances for survival. And although there still doesn't appear to be a shortage of frankincense on the market, a Boswellia die-off rate of 6 to 7 percent a year means supplies might not remain plentiful for long.

Oh well, there's always gold and myrrh.

Photos: Frankincense tree by Alexandre Baron via Flickr. Frankincense by Tiffany Baxendell Bridge via Flickr. Both used under Creative Commons license