Morphological and Physiological Damage by Surfactant-Polluted Seaspray on Pinus pinea and Pinus halepensis

Abstract

This paper reports morphological and physiological damage caused by polluted seaspray to coastal pine forests in Liguria (Northern Italy) and suggests the most reliable parameters for surfactant-pollution biomonitoring. Concentrations of surfactants in surface seawater, seaspray, and that deposited on Pinus halepensis and Pinus pinea needles were determined in samples from five sites. Decline of the pines in the Western part of Liguria was greater than in the East, and was associated with higher surfactant levels deposited on the crowns. Chloride content of needles was higher in damaged pines, even if it did not reach toxic levels. Stomata micromorphologies did not differ between species in the crown parts facing the sea, while differences were significant in the back crown parts that were not directly exposed to polluted sea breezes. Water content and noon water potential indicated interference in water relations of damaged trees. In conclusion, none of the investigated parameters was by itself a comprehensive index of surfactant damage. A simultaneous survey of several parameters is suggested to investigate the impact of surfactants on coastal vegetation. The most useful parameters were: directionality of crown damage, surfactant depositions on the needles, chloride accumulation in the needles, structural injury to epistomatal chambers, needle water content and potential.

Dendroecological study of Pinus halepensis and Pinus pinea in northeast coastal dunes in Tunisia according to distance from the shoreline and dieback intensity

“…This characteristic was observed for these species on the Mediterranean coast in Italy (Gellini et al, 1986;Bussotti et al, 1995;Nicolotti et al, 2005;Raddi et al, 2009) and in Spain (Diamantopouolos et al, 2000;Raventos et al, 2001). According to Raddi et al (2009), growth decline in Pinus pinea on the eroded coastal dunes in Italy may be attributed to greater exposure of the crowns to salty winds and surfactants and increased salinity of the water table.…”

The impact of sea erosion on coastal Pinus pinea stands: A diachronic analysis combining tree-rings and ecological markers

“…More recently, much lower values have been recorded (0.96-1.30 mg l À1 ; Nicolotti et al, 2001), due to the higher biodegradability of detergents and the lower consumption of poorly biodegradable organic ingredients (PBO), whose use was reduced in Italy by about 39% by 1996(EC Commission, 2004. Surfactants cause the deterioration of epistomatal wax structure (Bussotti et al, 1997) and reduce the surface tension of water, so favouring the needle uptake of NaCl (Richard et al, 1996;Nicolotti et al, 2005). On the Tyrrhenian coast, sea spray-exposed P. pinea needles showed 3-12 times higher chloride ion content compared to the opposite part of the crown, as well as more negative midday water potentials (Nicolotti et al, 2001, with higher water stress at increasing doses of surfactant concentrations in sprayed water .…”

Hygroscopic particles on leaves: nutrients or desiccants?

“…Coastal plants live in an environment with high particle deposition but are little affected by sea spray, and autochthonous plants seem to have adaptive mechanisms to prevent damage (Boyce 1954). However, ''polluted sea spray'' has been found in areas adjacent to landfills or near polluted coasts (Dowden et al 1978, Bussotti et al 1997, Nicolotti et al 2005). This has led to a type of forest decline in Southern Europe, probably because surfactants reduce the salt loading capacity of leaves (Bussotti and Ferretti 1998).…”