Division II.6 Pre-treatment before sending the samples to the laboratories for analysis

At least five trees of each main species present in the plot are sampled; the five samples are individually preserved in bags; for analysis, a composite sample shall be made by mixing equal quantities of each of the five samples (in case the five trees are analysed individually, the mean value is calculated for each element).

Great care shall be taken to clearly mark each sample (forest, number of plot, species, age of needles, etc.) before sending it to the laboratory for analysis. These identifications shall be given outside the bag (directly on the bag by indelible ink, or by clasping a label on the bag).