Phenolic Compounds in Needles of Norway Spruce Trees in Relation to Novel Forest Decline. II. Studies on Trees from Two Sites in Middle Western Germany

Abstract

Abstract The content of several phenolic compounds in needles of 20- to 30-year-old Norway spruce trees (Picea abies) was measured using HPLC. The results of two forestry sites in middle western Germany are reported in this paper. They are part of a research programme on novel forest decline which was carried out in various regions of Germany. Distinct amounts of picein, catechin, piceatannol glucoside, and other phenolic compounds were detected in the studied spruce needles. Additionally, their contents changed in relation to damage. Some compounds, especially catechin, showed increased levels in the needles of the damaged trees compared to the undamaged ones. Here, the values for the undamaged trees of the different sites were similar. Concerning the changes in picein contents, however, there was a great difference between the sites. p-Hydroxyacetophenone was detected in very low amounts only and did not correlate with damage. These results are compared with earlier findings from another site that shows severe damage. The role of phenolic compounds as indicators of tree damage is discussed.