... resources[http://www.teagasc.ie/advisory/forestry/rap/index.htm]). Thebiological features, for instance colonizing behaviour, spatialdistribution and mating system of Fraxinus species make themmodels of great interest for population ... Ash species in Europe: biological characteristics and practical guidelines for sustainable use, Oxford Forestry Institute,University of Oxford, U.K., 2005.[18] Gérard P.R., Fernandez M.J.F., ... challenges for the conservation and sustainable use of forest genetic resources, in: Vinceti B., Amaral W., Meilleur B. (Eds.), Challenges in man-aging forest genetic resources for livelihoods, IPGRI,...