Relation between altitude and chemical composition in seeds from species of Nothofagus, Laurelia and Laurelopsis near Valdivia (Chile)

In the forests near Valdivia (Chile), where a Mediterranean climate with oc ean tendencies predominates, evergreen and decoduous species of Nothofagus, Laurelia & Laurelopsisdominate. They regerate spontaneously, but due to wi nter low temperature and spring and even summer frosts, forest growth and p roductivity are limited. Moreover, overexploitation of native forests has d ramatically decreased the vegetation cover. In order to detect the potentia l adaptation of seeds to low temperature, seeds from several Nothofagu, Lau relia & Laurelopsis species growing close to the city of Valdivia were anal ysed for humidity, total lipids, fatty acids, soluble and total protein, st arch, fiber and ash. Results show high unsaturated/saturated fatty acids ra tioss. Outstanding are linoleic acid amounts in N. obliqua (82 %), N. alpin a (77.7 %). and Laureliopsis philippiana (75.8 %). These results may be poi nting to potential adaptation to maintain membranes fluid during periods of thermal stress.