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 Venezuel a were analyzed. Soils in the Uverito pine plantation were sandy, low in nu tritional quality, and deficient in available nitrogen and phosphorus conte nt. Pines grown on these soils presented in their needles higher concentrat ions of alpha-pinene, camphene, sabinene, myrcene + alpha-phellandrene mixt ure, beta-phellandrene, beta-caryophyllene, alpha-humulene, and a higher to tal monoterpene content than pines of the Sartenejas plantation, where soil s 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 du e to herbivory by the leafcutter ant Atta laevigata may induce, in part, th e differences observed between these pines and those of the Sartenejas plan tation. (C) 2000 Elsevier Science Ltd. All rights reserved.