Douglas fir is an exotic conifer from the western Pacific coast which was introduced into European forests at the end of the 19th century. Douglas fir plantations in Slovenia have proved to be excellent in resisting natural disasters so far. The selection of FRM (forest reproductive material) for the site of forestation is based on the results of provenance tests. In the Brkini region, the provenance test of 16 provenances was established within the framework of IUFRO project of the year 1971. A total yield is 602.9 m3/ha, the average survival rate is 43%. According to the vitality and the achieved diameter, the most positively deviating provenance is Yelm (West Washington), while Merrit (British Columbia) deviates negatively. Overall, the stand has no higher quality assortments than class C. According to the observed signs, the optimal choice would be provenance Cathlamet (Western coastal Washington). Douglas fir is an extremely variable tree species, the detection of statistically significant differences between provenances is aggravated by the high variability of tree signs within the provenance itself. With predicted climate change (rising temperatures and droughts), afforestation with an allochthonous conifer Douglas fir might be a possible substitute for the affected spruce. Models of climate change and the results of provenance tests are the basis for choosing the optimal provenances and location of their input.
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