Consequences of traditional management in the production and quality of copal resin (Bursera bipinnata (Moc. & Sessé ex DC.) Engl.) in Mexico

Abstract

Background Copal is a resin of ritual uses in Mexico, extracted from several species of trees of the genus Bursera. The effect of traditional management on phenotypical traits of copal trees has not been sufficiently studied. This research analyzed the traditional management and human selection on populations of Bursera bipinnata, and their influence on the quantity and quality of the resin produced by wild and managed trees.Method Management of copal were documented through semi-structured interviews and workshops. Samples of 60 trees from six wild and managed populations were selected to quantify the production of resin during two consecutive years. Fresh resin was collected to identify organic volatile compounds through gas chromatography and Principal Components Analysis (PCA); individuals were classified according to the amount and type of organic compounds produced.Results We identified management strategies from simple harvesting to seeds planting. The criteria for selecting managed trees and seeds are based on the quantity and quality of the resin produced and on higher quantity of resin yield per tree, which were much higher in managed than in wild trees: 190.17 ± 329.04 g vs 29.55 ± 25.50 g, and 175.88 ± 179.29 g vs 63.05 ± 53.25 g for the production seasons of 2017 and 2018, respectively. Twenty organic volatile compounds were identified and the PCA showed that managed trees produce higher percentages of compounds associated with scent.Conclusion Traditional management of Bursera bipinnata involves selective pressures, which generate differentiation of wild and managed trees that may represent incipient domestication through of silvicultural management.

Acaricidal and insecticidal activity of essential oils obtained from the aerial parts of three Mexican Bursera species

“…Like many other species of the genus, B. glabrifolia and B. linanoe have been employed as natural sources for wood and the aromatic resin copal (Blancas et al 2022;García-García et al 2022;Gigliarelli et al 2015;Hernández-Pérez et al 2011). Production of the latter, in particular, for ritualistic and medicinal use, usually in the form of an incense, dates back to the Pre-Columbian era (Abad-Fitz et al 2020;Blancas et al 2022). Today, copal is primarily obtained by communities located in central and southern Mexico, often by combining the exploitation of wild and agrisilviculturally managed populations.…”

“…An average adult specimen of B. glabrifolia produces an estimated 260 to 280 g of resin. Moreover, in some regions, B. linanoe has been subjected to human selection in order to improve copal yield (Abad-Fitz et al 2020). Being the resin's volatile fraction, the EO of this species has also been utilized for commercial purposes (Gigliarelli et al 2015;Hernández-Pérez et al 2011).…”