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.

The chemical compositions of the cuticular lipids of the needles of Norway spruce (Picea abies (L.) Karst.) and Sitka spruce (P. sitchensis) (Bong.) Carr.) were investigated by gas chromatography coupled with mass spectrometry. Fractionation of the wax extracts was carried out using column chromatography. Long chain secondary alcohols, diols and free fatty acids were found as major classes in both species: n-alkanes, n-alkenes, primary alcohols, a,w-diols, ketones and w-hydroxyacids constituted the minor wax classes. The presence of large quantities of estolides (high molecular weight biopolymers) was tentatively confirmed by saponification of the crude extracts which led to the recovery of large quantities of w-hydroxyacids, a,w-diols and free fatty acids. Qualitative differences between the two examined species were observed for minor constituents such as long chain aldehydes, methyl-and ethyl-esters and some terpenes. Quantitatively the two wax extracts differed mainly in their proportions of diols and fatty acids.

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