Editor's Note
This review summarizes a sustainability assessment of Boswellia in terms of habitat and population trends, harvesting/collection practices and uses, current threats and management measures. The authors conclude that sustainable harvesting and management practices combined with sustainable supply chains are needed to protect this species from overexploitation and thus endangerment.
Ethnopharmacological relevance
Boswellia serrata Roxb. ex Colebr. is a multiple-use tree species used for fodder, timber and is tapped for an oleo-resin known internationally as Indian frankincense or Indian olibanum. The main commercial uses of B. serrata oleo-resin are medicinal, religious, and in cosmetics and perfumery. B. serrata, like other frankincense species, is an important source of boswellic acid used in the pharmaceutical industry. India is the only producer of B. serrata oleo-resin, mainly from the states of Madhya Pradesh, Andhra Pradesh, Gujarat and Jharkhand. Market demands, harvesting and managing practices have pressured Indian frankincense populations into imminent decline and start to affect populations of African frankincense as buyers turn to look for substitutions.

Aims of the review
We have assessed the ecological status of Indian frankincense based on the assumption that current species management practices are not sustainable. This review summarizes the outcomes of this assessment in terms of habitat and population trends, harvesting/collection practices and uses, current threats and management measures.

Materials and methods
Firstly, we reviewed published information on B. serrata population biology and studies on impacts of wild harvest from across the geographic range of this species. Secondly, global trade data for B. serrata were analysed. Thirdly, we reviewed published information on B. serrata management measures and cultivation practices.

Results
The five largest importers of frankincense from India in 2016–2017 were Trinidad & Tobago, Germany, Guatemala, Mexico and the USA, in order of volume. Total volumes exported were 102.8 metric tonnes in 2015–2016 and 74.56 metric tonnes in 2016–2017. Collection data are less readily available. What could be found, however, points toward market demand for Indian frankincense and its derivatives by far exceeding what can reasonably be harvested/collected without endangering populations of this species, opening the door to adulteration and substitution.

Conclusions
In conclusion, not only sustainable harvesting and management practices, but also establishing sustainable supply chains are needed to protect this species from overexploitation and thus endangerment.