Figure 4

Emission rates (ng cm⁻² h⁻¹) of myrcene and recovered RT sesquiterpene compounds from mountain birch trees with no (NRT), moderate density (MRT) and high-density (HRT) R. tomentosum growing in the understorey. Box plots represent median and interquartile range with bars representing highest and minimum values. Differences in emission rates between groups were tested with Kruskal-Wallis non-parametric tests with multiple pairwise comparison (Mann-Whitney U with Bonferroni corrections). Aromadendrene, Palustrol and Ledol were recovered only in MRT and HRT plots and were tested with Mann-Whitney tests. Different letters above the bars indicate significant difference between groups (P < 0.05).