Frankincense Production Research Articles

Frankincense: Art and Science of Resin

Abstract: Frankincense, derived from the resin of Boswellia species, has been valued for millennia across diverse cultures for its aromatic, medicinal, and economic significance. This review provides an in-depth analysis of frankincense, encompassing its historical development, geographical distribution, and trade dynamics. The paper examines the economic aspects of frankincense production, including its impact on local economies and global markets. Detailed attention is given to the plantation and harvesting practices, production statistics, and the chemical composition of frankincense. Various types and colours of frankincense are discussed, along with quality assessment criteria. The review explores the diverse properties and applications of frankincense products, including their benefits and potential side effects. Additionally, it addresses sustainable harvesting practices, conservation efforts, and regulatory considerations. The paper concludes with a summary of recent scientific research, current challenges in the industry, and future directions for exploration and improvement.

The Significant, Threats and Management of Boswellia Papyrifera (Del.) Hochest Tree Species in Ethiopia: A Systematic Review

Boswellia papyrifera (Del.) Hochst is one of a combretum-terminal deciduous ecosystem with the key dry land tree forest in the world planet which belongs to the family Burseraceae. This review paper was presents to review the importance, threat and its management techniques of Boswellia papyrifera forest tree species in Ethiopia. Boswellia papyrifera woodland provides considerable economic, ecological, socio-cultural, traditional and industrial benefits in the dry lands of Ethiopia. The review showed that in Ethiopia Boswellia papyrifera tree population are declining at an alarming rate mainly due to overgrazing, absence of regeneration and saplings, pests, agricultural expansion, over tapping for frankincense production, poor policy and other interrelated factors. There are different important demands being made on the Boswellia papyrifera reducing conversion of woodland, using appropriate collection tools and methods, speedy environmental rehabilitation, improving tapping methods and timing, and provision of tree products as soon as possible in Ethiopia. Continuous capacity building training on sustainable utilizations and managements of Boswellia papyrifera woodland should also be provided for all relevant stakeholders.

Sustainability of frankincense production in Tigray, Ethiopia: an emergy synthesis

The frankincense from Boswellia papyrifera plays important roles in rural livelihoods and the national economy. On the other hand, Boswellia papyrifera is under threat of extinction. Nevertheless, little is known about the sustainability and fair-trade relationship of the current production system of the frankincense commodity. The current paper primarily analyzed sustainability of the production, processing, and exporting systems of frankincense production using the total emergy flows to the product. Data were primarily collected through key informant interviews and from secondary sources in the Tigray region, northern Ethiopia. An emergy synthesis method was used to assess the direct and indirect environmental energy requirements for the production, processing, and exporting of frankincense. The Emergy Sustainability Index (ESI), and Ratios were used as indicators of ecological sustainability. Whereas the Emergy Exchange Ratio (EER) was used to evaluate the level of fair trade of frankincense with importing countries. The average total emergy of the system was 50.14E+20sej/year, of which 3.92E+20sej are from local renewable, 45.20E+20sej from local nonrenewable and 1.02E+20sej from imported nonrenewable sources. The Percent Renewable (% Ren), Environmental Loading Ratio (ELR), Emergy Yield Ratio (EYR) and ESI were 7.82, 11.79, 49.50 and 4.19, respectively. The EER showed that the region exported 11.8 times more emergy in frankincense products than it received in the money paid for it in 2008/09, showing unfair trade between the exporting and importing countries. According to our results, it can be concluded that the current production, processing, and exporting of frankincense is not sustainable.

Policy Communication in Developing Frankincense Commodity in Humbang Hasudutan Regency

Frankincense commodities play an important role in agricultural commodity production in Humbang Hasudutan. Traditional processing has become a local wisdom that has been practiced for years. However, the threat of eroding customary forests and the lack of marketing are obstacles faced by farmers. The purpose of this research is to find out the communication of government policies in developing frankincense commodities. The method used in this research is descriptive with a qualitative approach. The results show that policy communication is able to encourage the effectiveness of frankincense agricultural development in Humbang. Policies regarding socialization to farmers to understand how the food estate program takes place, encourage community involvement in supporting the development plan. Efforts to create farmer welfare, encourage the strengthening of farmer organizations to be an important need in supporting the development of frankincense commodities. Strengthening the organization is considered capable of overcoming the problem of marketing difficulties of frankincense production from farmers.

Boswellia papyrifera a tree of economic importance in dry land Sudan: Dendrometric parameters and tapping characteristics

Abstract. Dafa-Alla M, Abdelkari HA, Abuelbashar AI, Hassan MH. 2022. Boswellia papyrifera a tree of economic importance in dry land Sudan: Dendrometric parameters and tapping characteristics. Asian J For 7: 10-16. We conducted this research in Abugadaf Natural Forest Reserve (ANFR) located within Blue Nile state, Sudan. The objectives were to examine dendrometric parameters and to analyze tapping characteristics for frankincense production. We randomly distributed 97 sample plots; in each, we counted B. papyrifera trees, measured their diameter at breast height (dbh), total height, bole height, and crown diameter, and examined the correlation between crown diameter and dbh. We examined 116 tapping spots made on 13 randomly selected trees. In each tree, we measured upper and lower tapping heights, calculated potentially untapped bole height, counted the number of tapping spots, measured their dimensions, recorded their directions, and compared mean numbers of tapping spots at four directions using one-way ANOVA (?=0.05). Results revealed that the distributions of dbh and the total height of tapped B. papyrifera followed a bell shape, and that of bole height and crown diameter followed a bell-shaped skewed to the right. Results revealed a significant (P=0.000) correlation between crown diameter and dbh (N=499) that trees were tapped at the four directions without significant difference (P=0.427) between mean numbers of tapping spots at the four directions. The study concludes that current tapping practice doesn’t strictly adhere to recommended tapping guides, particularly with minimum lower tapping height and preference of concentration of tapping in east-west directions.

EVALUATION OF ANTI TUMORIGENIC ACTIVITY OF Boswelliaserrata USING KB CELL LINE

Background: B.serrata is commonly known as Indian olibanum, it is mainly used in the production of Indian frankincense. B.serrata is used for many other purposes including asthma diabetes. The medicinal plant Boswelliaserrata has great potential for treating cancer. Since many cancer therapies have their origins in natural ingredients, this study aims to explore the anti-tumorigenic effect of B.serrata using KB cell line.Materials and methods: Seed of B.serrata was collected and extraction was done. Then the extract was added to the culture and the oral cancer cells were obtained from Pune. The cultured oral cells were incubated in a CO2 incubator. Treated oral cancer cell sample was done MTT assay and gene expression analysis.Result: The collected data from MTT assay and gene expression analysis tabulated using SPSS software. MTT assay results showed gradual decrease in cell viability with increase in concentration of Boswelliaserrata and the gene expression showed up regulation of caspase 3 and 9 expression.Conclusion: From the study, Boswelliaserrata has a significant effect on anti-tumorigenic activity; this might be due to the active bio components present in Boswelliaserrata extract.

Continuous resin tapping for frankincense harvest increases susceptibility of Boswellia papyrifera (Del.) Hochst trees to longhorn beetle damage

Frankincense is an important tree resin that provides a livelihood in the semi-arid lower highlands of East Africa. In the absence of sustainable management strategies, Boswellia papyrifera trees were being overexploited, leading to a depletion of genetic diversity, affected by pests and diseases, failure in natural regeneration, and hence a subsequent decline in socio-ecological benefits obtained from the species. We studied the impact of (i) continuous resin tapping without resting years and (ii) tapping or wonding intensity for frankincence production on the prevalence of longhorn beetle (Idactus spinipennis Gahan, Cerambycidae (sub family Lamiinae) damage in northern Ethiopia. We found that continuous resin tapping for frankincense harvest without adequate resting period made trees more vulnerable to longhorn beetle damage (P < 0.05). Trees rested for 10 and more years from resin tapping had less beetle damage occurrence than those tapped continuously (P < 0.05). Stem tapping intensity of more than 12 wounds per tree in one frankincense harvesting season caused high longhorn beetle damage incidence in Central Tigray (up to 90%) and Western Tigray (up to 80%). We recommend that B. papyrifera trees should have a resting period of at least 3 years and more after one year of continuous tapping. Depending on the size of a tree, wounding for frankincense harvest should be restricted to less than 12 wounds per tree. These measures would help the species develop resistance to longhorn beetle attack and maintain a healthy population for sustainable provision of ecosystem services including frankincense production in the dryalnds of northern Ethiopia.

Tapping height and season affect frankincense yield and wound recovery of Boswellia papyrifera trees

Boswellia papyrifera (Del.) Hochst is a threatened tropical dryland tree species. It is the source of frankincense, valued for its industrial, religious and traditional uses. This tree species is reported as under threat due to mortality from wound and inappropriate frankincense harvesting techniques. Two experiments were conducted simultaneously in the lowlands of North Western Gonder Zone, Ethiopia. The first experiment aimed to understand the effect of tapping height and tree size on wound recovery and frankincense yield and the second experiment dealt with understanding the effect of tapping schedule on survival and frankincense yield of different tree diameter sizes. Larger trees tapped at 1 m above the ground had the fastest wound recovery and highest frankincense yield. Higher tree survival was observed when tapping and resting schedule was alternated over years. However, mortality was higher when trees were tapped in consecutive years, without a resting year. The mean frankincense yield was 78 and 535 g/tree/year for small and large trees, respectively. Our result suggested that tree size, tapping height and resting time all have a significant effect on frankincense yield and wound recovery. Alternate year tapping of larger trees, with resting every three years, and avoiding tapping small trees are recommended for best wound recovery, survival, and to ensure sustainable production of frankincense.

Frankincense in peril

The harvest of plant parts and exudates from wild populations contributes to the income, food security and livelihoods of many millions of people worldwide. Frankincense, an aromatic resin sourced from natural populations of Boswellia trees and shrubs, has been cherished by world societies for centuries. Boswellia populations are threatened by over-exploitation and ecosystem degradation, jeopardizing future resin production. Here, we reveal evidence of population collapse of B. papyrifera—now the main source of frankincense—throughout its geographic range. Using inventories of 23 populations consisting of 21,786 trees, growth-ring data from 202 trees and demographic models on the basis of 7,246 trees, we find that over 75% of studied populations lack small trees, natural regeneration has been absent for decades, and projected frankincense production will be halved in 20 yr. These changes are caused by increased human population pressure on Boswellia woodlands through cattle grazing, frequent burns and reckless tapping. A literature review showed that other Boswellia species experience similar threats. Populations can be restored by establishing cattle exclosures and fire-breaks, and by planting trees and tapping trees more carefully. Concerted conservation and restoration efforts are urgently needed to secure the long-term availability of this iconic product. Wild plants anchor ecosystems and local economies. The iconic resin frankincense comes from Boswellia trees. This study documents the population collapse of B. papyrifera, the main frankincense source, throughout its range, suggesting conservation and restoration is vital.

Boswellia occulta (Burseraceae), a new species of frankincense tree from Somalia (Somaliland)

The new species Boswellia occulta is described from a small area in the Ceel Afweyn District of Somaliland (northwestern Somalia), where it is locally of considerable socio-economic importance. Although used for frankincense production by many generations of local harvesters, it has been unknown to science until now. Apart from the recently collected type material, it is also known from a sterile and hitherto misunderstood collection made in 1945. The simple-leaved Boswellia occulta is morphologically compared with B. sacra and B. frereana, the two major frankincense-producing species in the region, both with imparipinnate leaves, and it appears to be most closely related to B. sacra. The new species is the only simple-leaved species of Boswellia known outside Socotra.

Endogenous phytohormones of frankincense producing Boswellia sacra tree populations.

Boswellia sacra, an endemic tree to Oman, is exposed to man-made incisions for commercial level frankincense production, whereas unsustainable harvesting may lead to population decline. In this case, assessment of endogenous phytohormones (gibberellic acid (GA), indole-acetic acid (IAA), salicylic acid (SA) and kinetin) can help to understand population health and growth dynamics. Hence, it was aimed to devise a robust method using Near-Infrared spectroscopy (NIRS) coupled with multivariate methods for phytohormone analysis of thirteen different populations of B. sacra. NIRS data was recorded in absorption mode (10000–4000 cm-1) to build partial least squares regression model (calibration set 70%). Model was externally cross validated (30%) as a test set to check their prediction ability before the application to quantify the unknown amount of phytohormones in thirteen different populations of B. sacra. The results showed that phytohormonal contents varied significantly, showing a trend of SA>GA/IAA>kinetin across different populations. SA and GA contents were significantly higher in Pop13 (Hasik), followed by Pop2 (Dowkah)–an extreme end of B. sacra tree cover in Dhofar region. A similar trend in the concentration of phytohormones was found when the samples from 13 populations were subjected to advance liquid chromatography mass spectrophotometer and gas chromatograph with selected ion monitor analysis. The current analysis provides alternative tool to assess plant health, which could be important to in situ propagation of tree population as well as monitoring tree population growth dynamics.

Frankincense Revisited, Part I: Comparative Analysis of Volatiles in Commercially Relevant Boswellia Species.

The genus Boswellia comprises many species which are famous for their production of frankincense, a fragrant gum resin. In the published literature, manifold studies on the volatiles and semivolatiles in individual samples of these gum resins exist, yet very few studies have investigated multiple samples. Contradictory results with regard to the volatile composition exist in literature. In this first part of the study, a large sample set (n=46) of mostly commercially obtained gum resins and essential oils was investigated by solid-phase microextraction gas chromatography/mass spectrometry. A total of 216 compounds were identified or tentatively identified from the four commercially relevant species, namely B.sacra, B.serrata, B.papyrifera, and B.frereana, and the statistical evaluation of the resulting chemical profiles allowed a clear distinction between the species by their volatile profile. With only few exceptions, the designated species was found to be in accordance with the composition reported in reliable literature sources and detected in botanically identified samples. Chemotaxonomic marker substances were suggested to facilitate the differentiation of commercial gum resins or essential oils based on their volatile profile.

Determination of Growth Rate and Age Structure of &lt;i&gt;Boswellia papyrifera&lt;/i&gt; from Tree Ring Analysis: Implications for Sustainable Harvest Scheduling

Boswellia papyrifera is a multipurpose deciduous species that grows in Combretum – Terminalia deciduous woodlands of Ethiopia. It is widely known for its commercial frankincense production. The B. papyrifera woodland is under a problematic state of population decline due to heavy encroachment and unsustainable tapping. To sustainably manage such a sensitive ecosystem needs exact knowledge of growth rates and age structure of trees where such information on tropical trees under natural condition is rather poor. In this study growth rate and age of B. papyrifera was determined from tree ring analysis. The study was carried out in Lemlem Terara, Metema district, Ethiopia. The mean annual diameter growth rate of B. papyrifera derived from the mean ring-width is 2.32mm and varies among sample trees. All sampled trees showed a comparable general growth trend which can be divided into three phases – i) good growth in the beginning, ii) phase with depression in middle and iii) increase in ring width. The average age of B. papyrifera trees growing in the study site is estimated to be about 75 years. Although there is strong correlation between diameter of a tree and age, the result from this study highlighted that age-size relations should be used cautiously as the diameter may not reflect the true age. The result from this study is important input to develop strategic plan for the species regarding tapping frequency and intensity as per the annual increment of the species. For further dendrochronological studies of the species, it is recommended to take samples from different size classes and slope gradients for better and reliable results. In future, the use of tree ring analysis as a tool to understand growth dynamics and age structure of trees species, and their response to climate variability should be strengthen in Ethiopian. Keywords: Boswellia papyrifera, Annual growth rings, Diameter growth rate, Age structure, Ethiopia.

Impact of membership in frankincense cooperative firms on rural income and poverty in Tigray, Northern Ethiopia

Rural households in northern Ethiopia had no access to frankincense production and trading. However, following the recent devolution of forest use-rights, rural communities in norther Ethiopia are getting access through organizing frankincense cooperatives. This study examines the effects of membership in the rural frankincense firms on income and poverty by applying instrumental variable, propensity score matching and Rosenbaum bounds methods on survey data from five rural villages in frankincense woodland areas of Northern Ethiopia. Results indicate that both membership and amount of households' investment in shares in the frankincense cooperative firms have statistically significant positive welfare impacts. The average treatment effect on the treated from matching methods for the welfare indicator variables (log-transformed household per adult equivalent income, poverty head count, poverty gap, and poverty severity) are robust against hidden bias arising from unobserved confounding variables that simultaneously affect assignment into frankincense forest cooperative firm membership and each of the welfare indicator variables.

Frankincense yield is related to tree size and resin-canal characteristics

Boswellia papyrifera Hochst. is the most important global source of frankincense. Tree numbers are rapidly decreasing in many populations of B. papyrifera in Ethiopia, where most of the internationally traded frankincense comes from. Improper tapping is among the frequently mentioned reasons for this decrease within populations. We still lack sustainable techniques for frankincense tapping, and these techniques are not yet tuned to individual trees since we are unaware how tree characteristics influence frankincense yield. This study investigates the relationships between different tree characteristics and their relation to frankincense yield. We selected 53 trees and measured frankincense yield and their DBH, tree age, number of leaf apices, radial growth, bark thickness, total resin-canal area, and total number of resin canals in a cross-section. Regression and path analysis were used to unravel cause-effect relationships between tree characteristics and frankincense yield. Frankincense yield was independent of the actual radial growth rate, but increased with increasing total resin-canal area in the bark, stem diameter, tree age, and the number of leaf apices. We show that frankincense yield by trees is not only a simple function of tree size. Remarkably, trees that grew slower over their whole life history produced more frankincense, suggesting an intra-specific trade-off in growth rate and frankincense production. Overall, this study thus shows that frankincense production is the result of complex plant trait networks and long term tree life properties. The results contribute to management regimes that minimize the damage to trees, while maximizing benefits in terms of frankincense yield and can also be used for selection and propagation of trees which are well suited for frankincense production.

Understanding Boswellia papyrifera tree secondary metabolites through bark spectral analysis

Decision makers are concerned whether to tap or rest Boswellia Papyrifera trees. Tapping for the production of frankincense is known to deplete carbon reserves from the tree leading to production of less viable seeds, tree carbon starvation and ultimately tree mortality. Decision makers use traditional experience without considering the amount of metabolites stored or depleted from the stem-bark of the tree. This research was designed to come up with a non-destructive B. papyrifera tree metabolite estimation technique relevant for management using spectroscopy. The concentration of biochemicals (metabolites) found in the tree bark was estimated through spectral analysis.Initially, a random sample of 33 trees was selected, the spectra of bark measured with an Analytical Spectral Device (ASD) spectrometer. Bark samples were air dried and ground. Then, 10g of sample was soaked in Petroleum ether to extract crude metabolites. Further chemical analysis was conducted to quantify and isolate pure metabolite compounds such as incensole acetate and boswellic acid. The crude metabolites, which relate to frankincense produce, were compared to plant properties (such as diameter and crown area) and reflectance spectra of the bark. Moreover, the extract was compared to the ASD spectra using partial least square regression technique (PLSR) and continuum removed spectral analysis. The continuum removed spectral analysis were performed, on two wavelength regions (1275–1663 and 1836–2217) identified through PLSR, using absorption features such as band depth, area, position, asymmetry and the width to characterize and find relationship with the bark extracts.The results show that tree properties such as diameter at breast height (DBH) and the crown area of untapped and healthy trees were strongly correlated to the amount of stored crude metabolites. In addition, the PLSR technique applied to the first derivative transformation of the reflectance spectrum was found to estimate the concentration of the metabolites reliably at higher coefficient of determination. The most influential maximum slope positions of the spectrum obtained through PLSR analysis of the petroleum ether extract (crude metabolites) and the pure compounds (incensole acetate and boswellic acid) were found to coincide and concentrate in the region between 1383–1406nm and 1861–1896nm. However, analysis on these two individual specific region absorption features relationship with the bark extract, using the continuum removed approach, was not as robust as the PLSR analysis.This reveals that the ability to estimate metabolites in the stem-bark of B. papyrifera using spectral analysis opens a new approach on how to manage B. papyrifera tree. Development of such technique provides quick and reliable information for decision makers to decide on when to tap or for how long to rest the trees. However, to implement the technique, further research need to be conducted to determine how B. papyrifera tree metabolites vary due to tapping. In addition, research to determine the lowest metabolites quantity threshold, useful for management of the tree, needs to be conducted.

Genomic sequencing and microsatellite marker development for Boswellia papyrifera, an economically important but threatened tree native to dry tropical forests.

Microsatellite (or simple sequence repeat, SSR) markers are highly informative DNA markers often used in conservation genetic research. Next-generation sequencing enables efficient development of large numbers of SSR markers at lower costs. Boswellia papyrifera is an economically important tree species used for frankincense production, an aromatic resinous gum exudate from bark. It grows in dry tropical forests in Africa and is threatened by a lack of rejuvenation. To help guide conservation efforts for this endangered species, we conducted an analysis of its genomic DNA sequences using Illumina paired-end sequencing. The genome size was estimated at 705 Mb per haploid genome. The reads contained one microsatellite repeat per 5.7 kb. Based on a subset of these repeats, we developed 46 polymorphic SSR markers that amplified 2-12 alleles in 10 genotypes. This set included 30 trinucleotide repeat markers, four tetranucleotide repeat markers, six pentanucleotide markers and six hexanucleotide repeat markers. Several markers were cross-transferable to Boswellia pirrotae and B. popoviana. In addition, retrotransposons were identified, the reads were assembled and several contigs were identified with similarity to genes of the terpene and terpenoid backbone synthesis pathways, which form the major constituents of the bark resin.

Parasitic plant in natural Boswellia papyrifera stands at Humera, Northern Ethiopia

In Boswellia papyrifera (Del.) Hochst natural stands, we studied the association of parasitic plants with B. papyrifera trees from which frankincense was tapped and marketed for domestic and export markets. Data on the rate of infection of parasitic plants on B. papyrifera was collected in three transects located at separate locations around Baha kar, northern Ethiopia. Each transect had ten circular sample plots of 400 m2 and separated by 100 m. Species composition, DBH, height, crown diameter, number of main, secondary and tertiary branches and number of parasitic plants on individual trees were recorded. Sixteen tree species were recorded in the combined sample plots. The parasitic plant associated with B. papyrifera was identified as Tapinanthus globiferus. This parasite infected 38% of Boswellia trees in sample plots. The infection rate of the parasitic plant varied from 1 to 33 per Boswellia tree. The infection of T. globiferus on B. papyrifera was predominantly limited to tertiary small branchlets arising from secondary branches; parasitic plants were absent on thick main and secondary branches. In all plots, infection of T. globiferus was exclusively limited to Boswellia trees. The influence of T. globiferus parasitism on growth of Boswellia trees and its influence on yield of incense production needs further investigation. Management of natural stands for frankincense production should include measures to reduce infection by T. globiferus.

Modelling the future of Boswellia papyrifera population and its frankincense production

Sustainable production of the aromatic forest product frankincense is at stake due to rapid decline in its resource base. This affects livelihoods of thousands of citizens and several global industries. A system dynamic model approach is used to predict the future population of Boswellia papyrifera trees and its frankincense yield for three decades (2010–2040) in Metema and Abergelle districts in northern Ethiopia. Data from studies on the ecology, distribution, rate of deforestation and participatory future scenario development were put together and analysed using a model platform developed with STELLA. Four alternative scenarios namely Business As Usual (BAU); Low Intervention Scenario (LS), High Intervention Scenario (HS) and Stabilization Scenario (SS) were used. The model predicts 3%, 8% and 37% of the current stem population to exist in 2040 under BAU, LS, HS scenarios, respectively in Metema. Similarly, 11%, 13% and 46% stem density is predicted under BAU, LS and HS, respectively for Abergelle. Test of model sensitivity shows adult mortality is the most serious problem facing the resource. Immediate management intervention should focus on reducing adult tree mortality followed by reducing deforestation. Medium and long term interventions need to focus on how to improve recruitment and afforestation/reforestation of the species.

First report of Lasiodiplodia theobromae causing canker on tapped Boswellia papyrifera trees in Ethiopia

Boswellia papyrifera (Burseraceae) is found mainly in the Amhara, Tigray and Benshangul Gumze Regions of Ethiopia (Vollesen, 1989). This economically important tree species is widely used for frankincense (incense) production. Incense is…