近日，国际期刊Journal of Applied Ecology 刊登了国外研究人员的最新研究成果“Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations。”，文章中作者揭示了乳香产量将持续下降。
乳香是一种带有芳香气味的树胶脂，据《圣经》记载，耶稣出生时，有来自东方的三位博士带着神秘礼物，来到耶路撒冷朝拜耶稣。
“东方三博士”进献的神秘礼物为黄金、乳香和没药。这三样礼物代表着当时可以献给国王的最稀有和最珍贵的贡品。
其中，乳香是一种带有芳香气味的树胶脂，取自沙漠里的乳香属树木，在古代用于祭祀，现在是一种重要的中药材。不幸的是，如今，乳香已经变得更为稀少，并且将会持续减少下去。研究人员在最新出版的英国《应用生态学期刊》上报告了此发现。
近年来，乳香属树木在树种繁衍上已经遇到困难。此前，生态学家们认为，当贸易商从此类树木上获取树脂时，树木自身便会变得衰弱。
在埃塞俄比亚工作的两年时间里，研究人员共监控了12株构树，其中6株被提取过树液，6株没有。他们发现，曾被提取过树液的构树，可以和未被提取过的构树一样正常繁衍。这排除了人类的干扰是其主要杀手的可能。相反，最大的威胁似乎来自放牧的家畜、火灾和一种叫天牛的昆虫。其中，天牛能够打洞，并钻进树皮里杀死树木，使构树只能成为森林火灾的燃料。
如果这些问题不能被及时地补救，该研究团队的模型显示，在未来的15年里，乳香的产量将会减少50%；而这对乳香的出口国，埃塞俄比亚和厄立特里亚国的经济将会是一个沉重的打击。（生物谷Bioon.com）
doi:10.1111/j.1365-2664.2011.02078.x
PMC:
PMID:
Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations
Groenendijk, Peter; Eshete, Abeje; Sterck, Frank J.; Zuidema, Pieter A.; Bongers, Frans
Keywords: Boswellia papyrifera;Ethiopia;frankincense;matrix model;non-timber forest products;regeneration bottleneck;resin;restoration;sustainable use;tapping Summary 1. Resins are highly valued non-timber forest products (NTFP). One of the most widely traded resins is frankincense, tapped from several Boswellia tree species (Burseraceae). Exploited Boswellia populations often show poor regeneration, but the demographic consequences of these bottlenecks are unknown. Here we report on the first large-scale demographic study of frankincense-producing trees. 2. We studied 12 populations of Boswellia papyrifera in northern Ethiopia, varying in altitude and productivity. Six of these populations had been tapped before and were tapped during the study. Survival, growth and fecundity were determined for 4370 trees and 2228 seedlings, in 22.8 ha over a 2-year period. We also studied a remote population where no grazing and tapping took place. Matrix models were used to project population growth and frankincense production under four restoration scenarios. 3. Population structures of both tapped and untapped populations showed clear gaps. Small seedlings were abundant in all populations, but none developed into persistent saplings. Such saplings were only present in the remote population. Fire and grazing are the likely causes of this regeneration bottleneck. 4. Adult mortality was high (6–7% per year) in both tapped and untapped populations, probably caused by beetle attacks and fire. Unexpectedly, tapped populations presented higher diameter growth rates and fecundity compared to untapped populations. These differences are probably caused by non-random selection of exploited populations by tappers. 5. Under the ‘business as usual’ scenario, population models projected a 90% decline in the size of tapped and untapped populations within 50 years and a 50% decline in frankincense yield within 15 years. Model simulations for restoration scenarios revealed that populations and frankincense production could only be sustained with intensive management leading to full sapling recruitment and a 50–75% reduction in adult mortality. 6.Synthesis and applications. Regeneration bottlenecks and high adult mortality are causing rapid decline in frankincense-producing tree populations in Ethiopia. This decline is unlikely to be a consequence of harvesting and is probably driven by fire, grazing and beetle attacks. Fire prevention and the establishment of non-grazing areas are needed. Our results show that other factors than exploitation may seriously threaten populations yielding NTFP.
