The analysis of douglas fir (Pseudotsuga menziesii (Mirb.) Franco.) growth within the lUFRO trial at "Gostović" Zavidovići

Abstract

The trail site at Gostovic has been set in 1972. withhin  the IUFRO program of investigation of various provenance of Douglas fir ( Pseudotsuga Menzoesii (Mirb) Franco. plant heigh, diametar, survival rate, volume of of the mid-range trunk and total volume per hectare has been investigated in tress at the afe of 32 ages. The study showed statistically difference in the height and the diameter which proves that there still exists a difference in the height and the diameter which proves that there still exists a difference between various provenances at the fas as height was concerned, whereas the larges diameter was reported in provenance 1936, Alberni (British Columbia Canada). The study showed statistically significant difference in the heigh and the diameter which proves that there still exists a differenee between various provenanees at the trial site. Provenance 1100 Grand Ronde Agency (Oregon,USA) proved to be best as that was height was concerned whereas the largest diameter was reported in provenance 1036 Alberni (bristih Columbia, Canada)

There were no statistically significant differences obtained for the survival rate, the volume of the mid-range trunk and the total volume per hectare. The 1099 Vasco Pine Grove (Washington, USA) showed the best survival rate. The best provenance, as far as the volume of the mid-range trunk was concerned, was the 1036 Alberni (British Columbia, Canada), and for the total volume per hectare it was the 1099 Vasco Pine Grove (Washington, USA). Heavy soil of the pseudoglay type does not seem to be suitable for Douglas fir, and much better results at the same age were achieved in other soil types.

In this trial mid-sizes for some Douglas Fir provenance exceeded the level reported by Schober. Since reliable conclusion about production possibilities of some species can be made only after one third of the production period, our results only suggest the provenance that could be used for introduction into some defined sites. The variability within and between the provenance in this trial can be applied in selection of the materials for growth of clone plantations or seed orchards.