Inter-population differences in the essential oils of Pinus caribaea needles.

Differences in volatile terpene content of Pinus caribaea needles and soil qualities between two pine plantations (Uverito and Sartenejas) in Venezuela were analyzed. Soils in the Uverito pine plantation were sandy, low in nutritional quality, and deficient in available nitrogen and phosphorus content. Pines grown on these soils presented in their needles higher concentrations of alpha-pinene, camphene, sabinene, myrcene+alpha-phellandrene mixture, beta-phellandrene, beta-caryophyllene, alpha-humulene, and a higher total monoterpene content than pines of the Sartenejas plantation, where soils were nutritionally richer and higher in nitrogen and phosphorus content. The hypothesis of the carbon/nutrient balance could explain these results. Alternatively, continuous stress on the pines of the Uverito plantation due to herbivory by the leafcutter ant Atta laevigata may induce, in part, the differences observed between these pines and those of the Sartenejas plantation.