Some Italian pine-woods on the Tyrrhenian coast (mainly Pinus pinea and Pinus pinaster) appear to have been deteriorating since nearly 20 years. From the experimental results of the present investigation, the main cause may be ascribed to the presence of both surfactants and salts in the sea-spray which is deposited onto the pine needles by south-westerly winds.

Norway spruce diebaek: Occurrence, isolation and biological activity 145 LEE,T.T.;ALVIN,N. S.;JEVNIKAR,J.J., 1982 : Regulation of enzymic oxidation of indole-3-acetic acid by phenols: structure-activity relationship. Phytochemistry 21, 51 7-523. OsBORNE, D. J.; CHEAH, K. S. E., 1982: Hormones and foliar senescence. In: Growth regulators in plant senescence (ed. JACKSON, M. B.; GROUT, B.; MACKENZIE, 1. A.). British Plant Growth Regulator Group, Monograph No. 8, 57-83. ScHiNDLBEGK, E., 1978: Identifieation of a growth inhibitor (4-hydroxy acetophenone residue) in male spruce flowers {Picea abies Karst.}. Silvae Genet. 27, 42-47. ScHONBOHM, E.; ScHONBOHM, E., 1984: Biophenole: Steuernde Faktoren bei der lichtorientierten Chloroplastenbewegung ? Biochem. Physiol. Pflanzen 179, 489-505. ScHiJTT, P.; BLASCHKE, H.; HOQUE, E.; KOCH, W.; LANG, K. J.; SCHUCK, H. J., 1983: Erste Ergebnisse einer botanischen Inventur des ,,Fiehtensterbens". Forstw. Cbl. 102, 158-166. SEMBDNER, G.; BORGMANN, E.; SGHNEIDER, G.; LIEBISGH, H.-W.; MIERSCH, O.; ADAM, G.; LisCHEWSKi, M.; SGHREIBER, K., 1976: Biological activity of some eoniugated gibberellins Planta 132,249-257. TOWERS, G. H. N.; ABEYSEKERA, B., 1984: Cell wall hydroxy tinnamate esters as UV-A receptors in phototropic responses of higher plants -a new hypothesis. Phytochemistry 23, 951-952. AbstractThe deterioration of the pine-woods on the tyrrhenian coast of Italy can be ascribed to a synergism between surfactants and sodium chloride. The destruetion of epicutieular wax in pine needles has been revealed by tbe electron microscope. Data on acid rain are reported.

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Leaves of London plane, chestnut, walnut, Italian alder and ailanthus were exposed to simulated acid rain (pH 3.5) with and without the addition of ABS, from the first opening of buds to the full growth of leaves. Examination in the SEM showed that the leaves were damaged by the solution, more if it contained ABS. Damage observed included alteration and disarticulation of the glandular hairs and trichomas, erosion and fusion of the epicuticular waxes with consequent occlusion of the stomata, and neoplastic formations in the mesophyll ("galls"). The d^egree of damage suffered also varied with the species.

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