No abstract

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.

Treatments with acidified solutions ofpH3.5cause alterations in the wax structure of the needles of silver fir and Norway spruce. The wax structures, especially those of the stomata, once they have been damaged, are not capable of complete reorganization even if the needle is repeatedly treated with distilled water.

Severe damage was caused to coastal forest vegetation by the Libeccio, a sea wind blowing against the Italian coast from W-SW. The behaviour of common cypress (Cupressus sempervirens), smooth cypress (C. glabra) and Monterez cyjress (C. macrocaypa) in response to the Libeccio aindstorms of 1990 was compared with t at ue to treatments with the surfactant ABS (sodium dDdecylbenzenesulphonate). As re ards both the nature and the intensity of the damage to the leaf waxes, the surge damage cause2 by the windstorms differed little from that produced artificially by ABS sprays.