Wild tree resins generate billions of dollars in revenue
annually but many species face extinction. The lansan
tree Protium attenuatum has disappeared across most of its
range as a result of overexploitation for its valuable oleoresin,
which is used as incense. This study in Saint Lucia
aimed to determine whether lansan resin could be harvested
sustainably. Over ?? months, ??? trees were tapped using ??
experimental methods, and compared with ?? controls.
Significantly more resin was produced by tapping the
same trees repeatedly, tapping trees with a wider girth, cutting
the same part of the trunk repeatedly, and, in particular,
spraying diluted sulphuric acid on the cut. Applying ? and
??% sulphuric acid boosted yields by ?? and ???%, respectively,
without negative impacts on tree growth, condition or
mortality. In contrast, traditional methods used by local tappers
were destructive, causing greater decay and infection,
slower growth rates and increased mortality. Results show
tappers can obtain more resin and maintain healthy populations
by tapping mature trees of $ ?? cm diameter at
breast height, using only one shallow cut per tree (refreshed
every ? weeks) and applying weak sulphuric acid solution. A
blind survey found consumers could not distinguish between
incense produced with or without this stimulant. A
national management plan has been devised whereby tappers
will be licensed and trained in the optimal method
and granted their own forest coupes to manage under
Forestry Department supervision. The methods and findings
may guide the sustainable use and conservation of
other resin-producing trees.