Boswellia serrata (Burseraceae: Salai) is endemic to India. It is one of the primary sources of frankincense (salai-guggul). Salai-guggul is a gum oleoresin trapped by scraping the tree bark. In recent years, the market demand for salai-guggul as a medicine has increased. The species has emerged as one of the important NTPFs and a livelihood for forest dwellers in central India. The method of tapping is sustainable and does not impact the vitality of the tree. The population is inferred to be stable based on field observation by multiple ecologists, and interviews with forest dwellers, and forest officials. Furthermore, herbarium and literature records indicate that this is a dominant species in the dry deciduous forests of Central India, chiefly distributed in central Highlands and peninsular India. There is sufficient natural regeneration through the seeds to sustain the population. 

Except for a few localised cases of habitat degradation from livestock overgrazing, forest fires, and landslides, there are no significant threats impacting the population. It has an extent of occurrence (EOO) of 1,731,309.178 km² and AOO of 288 km². The population is not severely fragmented, and there are more than 100 locations known half of which fall within protected areas, biosphere reserves and are protected. There is no continuing decline in habitat availability or population size observed, Boswellia serrata is therefore listed as Least Concern (LC).    

Boswellia serrata is native to India (Andhra Pradesh, Telangana, Maharashtra, Karnataka, Tamil Nadu, Kerala, Odisha, Jharkhand, Madhya Pradesh, Uttar Pradesh, Bihar, Odisha, Haryana, Gujarat, Rajasthan). 

It was previously reported from Sri Lanka without strong evidence and hence it is considered erroneous. 

Observations are available for 100 localities in India: these form part of two broad sub-populations viz. peninsular India (Deccan Plateau, Western Ghats, Satpura, Eastern Ghats) and the central highlands (Vindhyas, and Aravalli). Out of 100 localities, half of the localities are part of biosphere reserves, either wildlife sanctuaries or national parks hence the area is protected. Consequently, the population is considered to be stable.

Based on the report by Dasgupta (MoEF & CC, India), out of 28 states in India, the species occurs in 17 states (excluding northeast and temperate Himalayas). The report notes that out of 11 territorial forest circles in Maharashtra, the species has been observed at 10 circles. The species was not reported from Nashik Circle in their report; however, it is frequently found around Sinnar. In Madhya Pradesh, out of 16 forest divisions Boswellia serrata is recorded in 15 divisions. The highest locality and density recorded is from the Umaria Forest Division. Similarly, Range Budhera and Ochapura at the Sheopur Forest Division covers hectares of Boswellia serrata-dominated forest (personal observation). Gujarat holds a greater density of B. serrata in the Banaskantha forest division, followed by Sabarkantha, Chota Udaipur, Vayara, and Aravalli. At Narmada district, Shoolpaneshwar Wildlife Sanctuary around 500 trees were observed in a radius of 4,000 square meters. This supports the species being common.

In Andhra Pradesh and Telangana, the study of 3,080 sample points in 21 forest divisions estimated more than 400 mature trees (Report from Institute of Forest Hyderabad). A report on the assessment of population status and removal of bio-resources in Forests with special emphasis on medicinal plants in Karnataka shows the occurrence of Boswellia serrata in 10 forest divisions including Bellary, Chitradurga, Davanagere, Kalburgi, Yadgiri, Bidar, Chikmagalur, Koppal, Hassan and Tumkur, with 0.565 m projected population of mature individuals. This report also reveals B. serrata is one of the most dominating species in the Bellary Forest division. In Rajasthan, Udaipur and adjoining Vindhyas are mostly dominated by B. serrata. It is also reported from Haryana around Panchkula and Yamuna Nagar hills covering Kalesar, Chhachhrauli, Panchakula and Pinjore Forest ranges. B. serrata is one of the common species at Deopur Forest Range in Balodabazar Forest Division, Chhattisgarh, where it grows in clay to shallow loamy, reddish-brown soil.

This is a moderate-sized tree, generally not more than 9-10 m high, and 1.5-1.8 m girth, with a spreading, flat crown. It grows gregariously on hot, arid hillocks, forming open forests, and is often associated with Sterculia urens, Buchanania lanzan, Butea monosperma, Garuga pinnata, Vachellia nilotica, Diospyros melanoxylon, Chloroxylon swietenia, Gardenia resinifera etc.. It is particularly abundant on the trap hills and slopes with moderate rainfall areas of the Deccan, the Satpura ranges, and the mountain ranges in the Aravalli. It often produces root-suckers, coppices and pollards. This tree grows well in loose, murum, rocky soils of dry deciduous forests, and sandstone habitats.

The fruit set under open pollination was low and ranged from 2.6 to 10 %, which considerably varies from tree to tree. Whereas the extent of fruit set in manual cross-pollination can be extended up to 20%. Pollination happens through insects, Apis dorsata (the giant Asian honeybee), and A. crenata var. indica (Indian honeybee) (Sunnichan et al. 2005).  

Fruit dehiscence is septicidal, split open along the septa, and wing seed disperses (Sunnichan et al. 2005). 

In protected areas, hectares of land with Boswellia serrata dominated forests have been observed; there are no immediate threats to these sites. The tree felling practices for wood have been halted long back, as many alternative sources like bamboo cultivation have been implemented for manufacturing paper or ply.  

The forest dwellers or tribes consider Boswellia serrata tree as an important source of their livelihood, and it is an important asset to them. In Central India, a tree is often gifted to the bridegroom during the marriage as a symbol of prosperity. Tapping of B. serrata has been done carefully to avoid damage to the tree. Interacting with the forest dwellers from Sheopur, only 25% of the total forest of B. serrata has been explored and permitted for tapping which is usually done on the trees that obtained more than 35 cm girth; therefore, no young sapling is damaged.

The Sahariya tribe in Madhya Pradesh practices rotational and sustainable harvesting of Boswellia serrata (locally called ‘chir’) to safeguard the salai trees, periodic intervals allow trees to recover. The tree is often referred to as a living being and human or a more-than-human entity and it is not limited to their livelihoods but spans other Sahariya rituals and cosmology (Mahalwal and Kabra 2023).

The method of tapping is sustainable and does not impact the vitality of the tree, with no serious apprehension. The method consists of blazing or shaving off a 6-inch-wide girdle of living bark to a depth of about one-half the thickness, and 2 to 6 feet height from the ground. Within from 4 to 6 days the wound is “freshened” by shaving off a very thin layer of bark from the old blaze down to within an inch of its lower border, and about one inch in height of new bark on the upper edge of the original wound. The hardened gum is scraped from the wound with a dull knife before each retapping operation, the tappers, and scrapers working in pairs. With the aid of the forest department, sustainable tapping practices for harvesting oleoresin have been implemented. 

The report of the rare and vulnerable Boswellia serrata from Odisha and Madhya Pradesh, and Jawahar Sagar Sanctuary, Rajasthan (Biswal and Nair 2008, Joshi and Shringi 2014, Chaubey et al. 2015) are based on local observations. Overall, the species occurs widely and is dominant in Deccan Plateau, Satpura, and Vindhya. In these areas there are no immediate or plausible threats that have been observed. Since there is extensive habitat protection and sustainable tapping practices are being followed throughout its range the species is not at risk.   

The rare occurrence of Boswellia serrata by Modi and Mathad (2016) in the Yadgir district of Karnataka does not provide any data on the population size and number of individuals.  

Shifting cultivation practices in Narmada district of Gujarat has resulted in the loss of Boswellia serrata and other tree forests around the villages. However, considerable areas adjoining these villages where B. serrata trees occur are protected as part of Shoolpaneshwar Wildlife Sanctuary.

Less than 5% of the population has been impacted by localised loss of forest due to agricultural expansion, road widening, and urbanisation. However, there is no direct impact on the overall population and habitat trend of Boswellia serrata.

Boswellia serrata is a primary source of frankincense, as well as, polysaccharide fraction removal, being one of the few non-coniferous sources of turpentine (Anon 1916, Anon 1998, Brendler et al. 2018). Turpentine from B. serrata is superior to that obtained from Pinus roxburghii and is used in paint and varnish industries (Sunnichan et al. 2005).

The wood is chiefly used as fuel. Charcoal is also made from its wood, and it is used for iron-smelting in Nimar (Madhya Pradesh). Once the wood of Boswellia serrata was used to make paper, but with the demand increasing for exuding gum resin the tree felling for paper halted (Birdwood 1871, Orwa et al. 2009).

The wood of Boswellia serrata is used to make artifacts, chapati roller boards, and pins in Khandesh (Nandurbar and Dhule districts of Maharashtra).

Wounds and cracks in the bark exude a fragrant gum-resin, which can diffuse, and when burnt creates an agreeable smell. It is used medicinally and as incense in India and traded in the Indian and foreign markets under the name of salai guggul, or Loban. However, Olibanon or frankincense chiefly used in different European countries, is yielded by several other species of Boswellia growing in tropical Africa and Arabia (Birdwood 1871, Stewart 1874).

Gajabhakshya or hastinashana are Sanskrit names often used for Boswellia serrata, suggesting that elephants use foliage as a part of their diet (Upaganlawar and Ghule 2009, Soumya et al. 2019). Green leaflets were used as fodder in the Aravali (Dular 2015).

Boswellic acid is pentacyclic triterpenes with strong anti-inflammatory activity; their most important source is the extract of the gum resin of Boswellia serrata (Du et al. 2015, Majeed et al. 2020).

In north Gujarat Boswellia serrata bark is often used as an adulterant in Tecomella undulata (Bignoniaceae).

In Central India, tapping oleoresin from Boswellia serrata as NTFP provides one of the important livelihood sources for forest dwellers. The oleoresin has been collected and sold to Indian herbal extraction companies to produce standardized and non-standardized B. serrata extracts mainly sold in the global market (Dular 2015). Extracted gum is also used as a binding agent in pharmaceutics (Chaudhari et al. 2011).

India is the primary supplier of frankincense derived from the oleoresin of Boswellia serrata (Brendler et al. 2018). It traded in different grades and forms including dried gum, gum extract, oil, resin extract, powder, and water extract.

Boswellia serrata has emerged as one of the most traded herbal raw drugs in recent years. As NTFP, the domestic herbal industry collected 655.47 metric tons of B. serrata oleoresin from wild sources (Gorya and Ved 2017). Madhya Pradesh (Sheopur district) supplies large quantities of oleoresin, mainly harvested by forest tribals as one of the sources of livelihood. About 530 tonnes of oleoresin were reported to be harvested from Madhya Pradesh (Bhattacharya and Hayat 2004), followed by Gujarat, Maharashtra, and Andhra Pradesh (Yogi et al. 2018), from 2008 to 2013. India is said to export 102.8 (2015-16) and 74.56 (2016-17) tonnes of oleoresin annually (Brendler et al. 2018)

The ex-situ conservation and multiplication practices of Boswellia serrata have been initiated at the forest nurseries in Maharashtra, Madhya Pradesh, and Gujarat.

As Boswellia serrata oleoresin emerged as a good source of revenue for the forest dwellers, in situ, monitoring and plantation of Boswellia serrata saplings has been carried out at Sheopur (Madhya Pradesh), with the help from the Forest Department of Madhya Pradesh. The aim of these plantations is to restore degraded land while simultaneously generating livelihoods for the forest dwellers. To protect the plantation from livestock grazing and burning the boulders are built around the plantation, and the site is continuously monitored. Also, a few workshops on Sustainable Harvesting Practices (in the context of tapping oleoresin) for the local inhabitants have been conducted regularly to spread the awareness and importance of the trees. 

Undertaking niche modelling (ENM, following climate models prediction by Rajpoot et al. 2020) to analyse possible habitat to grow Boswellia serrata would be beneficial to increase the present stable population. The commercial plantation initiative in the areas projected by ENM may help to supply the future demand for NTFP (oleoresin).