Molecular genetic tools to infer the origin of forest plants and wood

Most forest tree species exhibit high levels of genetic diversity that can be used to trace the origin of living plants or their products such as timber and processed wood. Recent progress to isolate DNA not only from living tissue but also from wood and wood products offers new opportunities to test the declared origin of material such as seedlings for plantation establishment or timber. However, since most forest tree populations are weakly differentiated, the identification of genetic markers to differentiate among spatially isolated populations is often difficult and time consuming. Two important fields of "forensic" applications are described: Molecular tools are applied to test the declared origin of forest reproductive material used for plantation establishment and of internationally traded timber and wood products. These applications are illustrated taking examples from Germany, where mechanisms have been developed to improve the control of the trade with forest seeds and seedlings, and from the trade with wood of the important Southeast Asian tree family Dipterocarpaceae. Prospects and limitations of the use of molecular genetic methods to conclude on the origin of forest plants, wood, and wood products are discussed.