Efeito alelopático das folhas de Schinus terebinthifolius Raddi em espécies nativas da restinga de Massambaba

Abstract

Schinus terebinthifolius Raddi (Anacardiaceae) is a South America species with large geographical distribution, being common in Coastal Sandy Banks areas. Its ecological plasticity and good biotic interactions makes it a key specie in habitat restoring, but its dominance may be related to the release of allelopathic compounds. The objective of the study was to analyze the seasonal variation of Schinus terebinthifolius aqueous extracts and essential oils allelopathic effects on restinga target species (Cereus fernambucensis, Erythroxylum ovalofolium, Pilosocereus arrabidae), a crop species (Lactuca sativa) and itself (autotoxicity). For that, leaves were collected seasonally at restinga de Massambaba for aqueous extract preparation and essential oils extraction. Aqueous extract was obtained by drying the leaves at 60º C, grinding it in a blender, diluted with distilled water and filter, generating 5, 10, 15 and 20% concentrations. Oil extractions were performed by 300 g of fresh leaves hydrodistillation. Essential oil composition was performed by gas chromatography using SPME fiber. The phytotoxic effect was evaluated on germination percentage, speed of germination, hypocotyl and root growth, electrolyte leakage and dry mass of the target species. Aqueous extracts allelopathic effects were observed for all target species, especially for natives. Its effects varied with the seasons, being dose-dependent and species-specific. Schinus terebinthifolius essential oils could also inhibited target species germination and growth. Its effects varied with the seasons and target species. It is suggested that these differences are related to S. terebinthifolius phonological phases and restinga de Massambaba environmental conditions. This phytotoxic effect, if proven in the field, may restrict Schinus terebinthifolius use in habitat restoration