Abstract. Cuticular wax composition of healthy and and declining mature Norway spruce trees [Picea abies (L.) Karst.] was investigated in five European forest areas. The amount of extracted wax and the content of alkanes and secondary alcohols were analysed as a function of the factors "sample area" (five areas, detailed below), "needle age" (current year to 2 years) and "decline class" (Class O to Class 2). Using a GC-MS, alkanes from C20 to C31 and the following alcohols were quantified: 10-nonacosanol, 5,10-nonacosandiol, 4,10-nonacosandiol and the triterpenol 24-methylenecycloartanol. According to our results, the total wax content as well as the alkane and alcohol content of waxes show a large variation corresponding to sample area and needle age. Ageing caused a highly significant increase in alkane content and a highly significant decrease in total wax and alcohol content. The decline class significantly influenced only the content of the long chain alkane C31 (increase), the secondary alcohol 10-nonacosanol (decrease), and the triterpenic alcohol (decrease). Total wax weight was not influenced by tree damage. Thus, according to our results, needle ageing and progressive tree damage are correlated to different changes in the examined parameters.

No abstract

L~, P. 1994. Alteration of element contents in guard cells of Norway spruce (Picea abies) subjected to ozone fumigation and (or) water stress: X-ray microanalysis study. Can. J. Bot. 72: [86][87][88][89][90][91][92]. Two clones of Norway spruce Picea abies (L.) Karst. (Gerardmer clone and Istebna clone) were subjected to an ozoneenriched atmosphere. The X-ray microanalysis of elements present in the guard cells showed a decrease in potassium for the Gerardmer clone along with a larger closing of guard cells and an increase in calcium contents; for the Istebna clone, ozone did not affect these contents. When a drought stress was applied, an increase in calcium content of guard cells of the Istebna clone was also found. However, the potassium content was smaller in this case for the two clones and could well be due to stomata1 closure. When ozone and drought stress were applied together, the potassium content in the Istebna clone was not affected, but for the Gerardmer clone, ozone reduced the decrease in potassium content that occurred as drought stress developed. However, calcium (and manganese) content increased significantly when the Gerardmer clone was exposed to ozone. It seems likely that the Gerardmer clone is sensitive to ozone and when subjected to a drought stress this sensitivity is increased. For the Istebna clone, the resistance to ozone is unaffected by the drought stress treatment. The Istebna clone, however, seems sensitive to drought. These characteristic responses in the two different Norway spruce clones are probably due to genetic differences and may explain the contradictory observations in the response of the stomata during the simultaneous implementation of the complex stresses. et L O O S V E L~, P. 1994. Alteration of element contents in guard cells of Norway spruce (Picea abies) subjected to ozone fumigation and (or) water stress: X-ray microanalysis study. Can. J. Bot. 72: 86-92. Deux clones de Picea abies (L.) Karst. (GCrardmer et Istebna) ont Ct C soumis i une atmosphkre enrichie en ozone. Lamicroanalyse X des ClCments presents dans les stomates a montrC une baisse des teneurs en potassium en relation avec une fermeture plus importante des stomates et une augmentation en calcium, ceci pour le clone GCrardmer; pour le clone Istebna, I'ozone n'affecte pas les teneurs de ces deux ClCments. Lorsqu'un stress hydrique est appliquC, une augmentation des teneurs en calcium dans les stomates du clone Istebna est enregistrke mais les teneurs en potassium sont plus faibles pour les deux clones dans ces conditions en relation avec une fermeture des stomates. Lorsque les deux traitements, ozone et stress hydrique sont appliquCs simultantment, les teneurs en potassium n'holuent pas par rapport au traitement stress hydrique pour le clone Istebna, mais pour le clone Gerardmer, I'ozone rtduit la baisse en potassium qui se produit lors du stress hydrique. Par contre les teneurs en calcium (et manganbse) augmentent considCrablement pour le clone GCrardmer par rapport au traitement ozone.Le clone GCrard...