Differentiation of seedlots of grand fir (Abies grandis Lindl.) by the analysis of stable isotopes.
The proof of the authenticity of seed lots is basic for the privately organized certification and is used in the control case, the discovery of violations of the Act on forest reproductive material (Forstvermehrungsgutgesetz, FoVG) in Germany. A method is presented that allows to compare seed-lots according to their largely tamper-proof signatures of stable isotopes and content of the elements C, N, H, O. This comparison allows an examination of individual cases with the help of a multivariate discriminant analysis. By crossvalidation in 79 out of 110 (72%) comparisons made it was possible to completely differentiate the samples from nine German seed stands and two imported seed lots from North America. In addition, for a test data set comprising of stable isotope signatures from another German and a North American seed lot, their non-affiliation could be confirmed. Significant differences between seed lots of different stable isotope delta-values became obvious.