Lansan or incense (Protium attenuatum) is and was a highly prized commodity and has long been used in our society; in blessing, as an insect repellant and even for medicinal purposes as in the relief of sinus congestion and arthritis.
Unfortunately lansan is being illegally harvested and as many of the harvesters are opportunistic their manner of harvesting is such that causes severe to fatal injury to the trees. Often times the trees back is indiscriminately slashed and this so far has caused death of hundreds of trees. Sustainable Management of this flagship species is therefore necessary.
Lansan is endemic to the Lesser Antilles and is found in Guadeloupe, Dominica, Martinique, St. Lucia and St. Vincent and has been heavily depleted and is believed to be under threat. In fact it appears that St. Lucia has the largest remaining population of lansan in the Lesser Antilles. A survey is soon to be carried out to determine its IUCN (International Union for Conservation of Nature) status.
An experiment was carried out to determine the best method of harvesting which would produce increased yields while minimizing any detrimental effects to the trees. A series of 7 different cuts were made where some were sprayed with a 5 % concentration of sulphuric acid and others not. Four diametric classes were used from 15 cm to >30cm. The experiment sites were Barre de L’isle and Chassin. Lansan was collected every two weeks and new cuts were made at that time no deeper than the cambium layer.
Funding for this project was provided by Flora and Fauna International, in collaboration with the Global Tree Campaign and The Ministry of Agriculture, Lands, Fisheries and Forestry.
This is done with the aim of protecting the species from extinction while continuing to provide a sustainable livelihood activity. This project began in 2009 and it is hoped that with further studies and continued conclusive data a sustainable harvesting method will be adopted by all harvesters ensuring that everyone gets piece of the pie now and in the future.
The preliminary results of the lansan project are as follows:
¨ There’s increased production of resin (lansan) when sulphuric acid is added to the cuts.
¨ The effects of the sulphuric acid on tree health and growth is yet to be determined, though there does not seem to be any negative effects thus far.
¨ The effects of the sulphuric acid on human health is not known.
¨ Recommendations were made for testing of the lansan to determine it’s quality although feed back received from various priests who have used some of the lansan harvested are reported as saying the quality is very good and even better than some imported lansan which they occasionally use.
Market and consumer research is currently ongoing via surveys of market vendors who sell lansan.