In the radio talk, the problem of the restoration of Slovenian forests after the ice storm in 2014 was a main topic and we spoke about the suitability of different tree species for the regeneration. A special focus was on the possibilities offered by non-native tree species with a special focus on Douglas fir.
B.06 Other
COBISS.SI-ID: 5192870Douglas 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.
D.10 Educational activities
COBISS.SI-ID: 5134502A sleet storm in February 2014 and following bark beetle outbreak destroyed most of the Norway spruce monocultures and forests with a higher share of spruce in forest district Planina. In order to evaluate the adequacy of the wider use of Douglas fir in this area, we have analyzed four mixed plantations of Pseudotsuga menziesii and Picea abies in the areas around Počivalnik and Stari vrh. For both tree species, we have evaluated various types of damages at the diameter classes. We have also analysed the density and height structure of P. menziesii saplings at different distances from the mother forest stand. We have verified that Douglas fir on the studied areas has been preserved in small stands and compared to Norway spruce, it showed a significantly higher resistance to ice storm and bark beetle outbreak. Its vitality is even better than that of Norway spruce. In favorable light conditions, natural regeneration is present, even more abundant than expected. Recorded damage of the regeneration is mostly due to herbivorous browsing.
D.10 Educational activities
COBISS.SI-ID: 5135526