Báo cáo khoa học: The role of marine salt and surfactants in the decline of Tyrrhenian coastal vegetation in Italy

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: " The role of marine salt and surfactants in the decline of Tyrrhenian coastal vegetation in Italy...
Nội dung trích xuất từ tài liệu:
Báo cáo khoa học: " The role of marine salt and surfactants in the decline of Tyrrhenian coastal vegetation in Italy" Original articleThe role of marine salt and surfactants in the decline of Tyrrhenian coastal vegetation in Italy F Bussotti P Grossoni F Pantani 1 Dept of Plant Biology, Laboratory of Forest Botany, University of Florence, Piazzale delle Cascine, 28, I-50144 Florence; 2 Dept of Public Health, Epidemiology and Environmental Analytical Chemistry, Section of Analytical Chemistry, University of Florence, via G-Capponi, 7, I-50100 Florence, Italy March 1994; (Received 22 accepted 6 September 1994)Summary — The decline of coastal vegetation is a phenomenon affecting some areas of the Mediter-ranean region and Australia; it is due to the presence of surfactants in marine aerosols, a conse-quence of sea pollution by detergents. This paper gives some observations made at various sitesalong the Tyrrhenian coast in Italy. The authors show that the presence of surfactants in the environ-ment correlates with the presence of sea salt, and that the impact of surfactants on vegetation is localand occurs only in association with strong sea winds. The study of the synergistic effect of surfac-tants and sea salt on the crowns of trees exposed to aerosols suggests that the surfactant can causedirect damage, while the absorption of sea salt is enhanced by the presence of the surfactant only whenexposure to aerosol is prolonged, or if it is administered in very high concentrations.Pinus pinea L / marine aerosol / surfactant / NaCl / leaf absorption / crown damageRésumé — Le rôle du sel marin et des agents tensio-actifs dans le dépérissement de la végé-tation côtière tyrrhénienne en Italie. Le dépérissement de la végétation côtière est un phénomènequi concerne un certain nombre de zones de la Méditerranée et de l’Australie; il est dû à la présenced’agents tensio-actifs, engendrés par la pollution hydrique de détergents dans les aérosols marins. Notrerecherche fait le point de 10 années d’observations d’un certain nombre de localités italiennes du lit-toral tyrrhénien. II en ressort que la présence d’agents tensio-actifs dans l’environnement dépend dela présence de sel marin ; leur impact sur la végétation est local et il est limité aux périodes de vent demer fort. L’étude de l’action synergique des agents tensio-actifs et du sel marin sur les houppiers desplantes exposées aux aérosols suggère l’existence d’un dommage direct dû à l’agent tensio-actif enquestion, tandis que l’absorption de sel marin n’est favorisée par la présence de l’agent tensio-actif quedans des conditions d’exposition prolongée à l’aérosol ou s’il est administré en fortes concentrations.Pinus pinea L / aérosol marin/ tensio-actifs / NaCl / absorption foliaire / dommages au houppierINTRODUCTION that many kilometres from the coast are (Grossoni et al, 1990; Raddi et al, 1992). However damage of this type is alwaysSince the early 1960s the vegetation in a num- extremely localized. According to the major-ber of coastal areas has been affected by a ity of the authors mentioned above this dam-kind of decline which, in terms of both quality age is primarily due to the fact that the crownand intensity, is very different from the nor- absorbs an excess of sea salt, which thenmal damage caused by salt. In actual fact the accumulates in the leaf tissues. In fact, thespontaneous coastal vegetation has adapted damage always appears to be associatedto the action of salt, so that natural marine with high quantities of Na and Cl in the + -sprays only cause rather limited damage, con- leaves. In coastal species, in normal condi-sisting primarily of changing the shape of the tions, the absorption of sea salt is limited bycrown or in the deat ...