Generally, modelling the non-linear and complex process of current annual height increment of any timber species is significant both in dendrometric studies and in practical forest exploitation. Using the methods of artificial intelligence based on neural networks, we attempted to extract the non-linear process of height increment from the observed data sets and to generate a prediction as accurately as possible. The first part of the chapter analyses height increment of different provenances of young Douglas-fir (Pseudotsuga menziesii) stands at different sites in Serbia. After that, the corresponding data-based models of height increment were evaluated. The models of suitable sites, standard sites and unsuitable sites for Douglas-fir fast growth and development, as well as the models for superior provenances and inferior provenances, are proposed.

Popović V., Lavadinović V., Bjelanović I., Lavadinović V.: Dependence of Douglas-fir mean height on geographic origin of Canadian provenances in seedlings nursery conditions. Ekológia (Bratislava), Vol. 32, No. 3, p. 328-334, 2013. Seed and seedling tests, performed with the aim of acquiring knowledge about the genetic potential of selected provenances, are generally one of the first trials in a complex system of comparative examinations to be conducted upon the introduction of alien tree species. This paper presents the results of the investigation of the dependence of the mean height of 14 Canadian origin Douglas--fir provenances, originating from latitude 49º 10' to 51º 35' , longitude 11 º 20' to 120º 10' and the altitude of 488 to 1,070 m, on the geographic origin. Understanding the variations in the mean height of a seedling is of major importance for acquiring knowledge on genetic potential of selected provenances, which are one of the key parameters for the introduction of Douglas fir into relevant forest sites in Serbia.

Daños por heladas tardías en pino oregón, Patagonia argentina 113 BOSQUE 26(3): 113-120, 2005 NOTA TECNICA Evaluación de daños por heladas tardías en ensayos de procedencias de pino oregón introducidos en el norte de la SUMMARY The susceptibility to late frost of the seed source used for afforestations at the moment it is one of the main adaptatives characteristic limiting the increase of the planted area of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in Argentinien North Patagonia Region. In two provenances trials of this species we registered frost injury caused by absolute minimum temperature of-7º C during spring. In both sites we found significant differences among treatments. We found a strong correlation between the percentage of frost injury and seed source longitude (r = 0.86) and with seed source altitude (r = 0.75) in the trail that registered the most rigorous minimum. In this trial we found also a weaker association with nursery mean heights (r = 0.55) and the origin latitude (r = 0.44). Considering that coastal origins are those of better potential growth, selection based only growth criteria could produce an indirect selection of susceptible genotypes. Finally we recommend the simultaneous evaluation of yield and susceptibility to be able to extend the specie cultivation towards other areas with increased frost risks. RESUMEN La susceptibilidad a las heladas tardías de la fuente de semilla actualmente utilizada es una de las principales características adaptativas que limitan la ampliación del área de plantación de pino oregón (Pseudotsuga menziesii (Mirb.) Franco) en la Región Norpatagónica de la Argentina. En dos ensayos de procedencias de esta especie se registró el daño provocado por heladas de primavera de hasta-7º C de mínima absoluta. En ambos ensayos se encontraron diferencias significativas entre los tratamientos. En el ensayo en el que se registraron mínimas más rigurosas pudieron establecerse correlaciones altamente significativas entre el porcentaje de daño por heladas con la longitud (r = 0,86) y altitud (r =-0,75) del origen de la semilla, y una menor asociación con la altura media de las plantas en vivero (r = 0,55) y la latitud de origen (r = 0,44). Considerando que los orígenes costeros son los de mayor potencial de crecimiento, estos resultados indican que la selección en base a ese único criterio podría producir una selección indirecta de genotipos susceptibles. Finalmente se recomienda la evaluación simultánea de rendimien-to y susceptibilidad para extender el cultivo de la especie hacia áreas de mayor riesgo de heladas. Palabras clave: pino oregón, mejoramiento genético, ensayos de orígenes, heladas, Patagonia, Argentina.

The morphology, anatomy, ecology and physiology of introduced tree species should be tested in order to confirm their autochthonous characteristics and justify their introduction. Douglas-fir (Pseudotsuga mensiesii Mirb/Franco) is a species with a very wide geographical range of distribution and an extensive altitudinal range. Its natural area of distribution stretches from New Mexico to Canada and from the Pacific to the Rocky Mountains. The species should be tested using the model of provenance tests in order to select the most adaptive and promising provenances to be introduced into new ecosystems of Serbia. This paper deals with the content of magnesium in the needles of Douglas-fir in different provenances originating from Canada. Magnesium is the most important mineral for all living organisms and affects a number of biochemical processes in plants.The research was carried out on fourteen different provenances of Douglas-fir originating from Canada on two different soil types - eutric cambisol and vertisol. All the trees of the study provenances were of the same age and grown under the same conditions on two different types of soil. The determined amounts of magnesium in the needles indicate that there are differences in the ability of certain provenances of Douglas-fir to absorb this element of nutrition from the soil.

The research on the interactions between the genetic potential of introduced provenances and the environmental features of the locations in which the plantations were established was carried out in Douglas-fir plantations in Serbia. The twoway ANOVA was conducted in order to study the effects of the site conditions in the localities of Douglas-fir provenance tests in Serbia on the anatomical properties of needles. These analyses look into the effects of two factors (locality and provenance) on the number of epithelial cells in the resin duct of Douglas-fir needles.