Preliminary communication
Results of Research on Douglas Fir Provenances in Ecologicaly Different Continenetal Parts of Croatia
Sanja Perić
; Hrvatski šumarski institut Jastrebarsko
Martina Tijardović
; Hrvatski šumarski institut Jastrebarsko
Anamarija Jazbec
; Šumarski fakultet Sveučilišta u Zagrebu
Abstract
Establishment of forest cultures in Croatia begun around 1970s. Since then, share of cultures in Croatian forest fund varies while today it amounts to about 3 %. New scientific knowledge points out to justifiable reasons of further and enhanced establishment of Douglas fir cultures in Croatia (especially spontaneous increase of suitable areas for their establishment such as former agricultural land). This paper presents results of scientific Douglas fir research conducted in the scope of project “Management of conifer cultures”. Numerous trials which have been established during the last 40 years (in the scope of activities of Croatian forest institute) with the aim of determining the most suitable provenances for establishment of conifer cultures in Croatia have provided first results. According to those results Douglas fir showed best growth success among all investigated species.
Douglas fir is one of the most valuable and important specie for timber production in the world. Combination of high quality wood with high productivity places Douglas fir on the top of the world’s timber production. In the country of its natural distribution this specie is the object of numerous scientific publications, while the research on Douglas fir success in Europe was conducted mostly in the scope of culture establishment. Its natural distribution spreads in the west part of North America. This specie is successfully introduced in almost all areas of temperate region in the world (Europe, southern part of South America and Australia) and in New Zealand. Douglas fir cultures occupies immense areas in North America where this species is naturally distributed.
Douglas fir successfully adapts to broad range of site conditions, while provides high incomes and high quality products. It successfully grows in different climatic conditions, especially on deep and aerated soils, with pH 5–6, while on heavy soils with higher water content shows lower success. Although Douglas fir is the specie with deep root system, morphology of roots depends on soil properties. In the context of climate change Douglas fir seems to be very interesting commercial specie for Europe since it adapts easier to conditions of temperature increase and rainfall decrease during the vegetation period. Consequently, Douglas fir could be superior to Norway spruce which is currently most important economic specie in the Europe. Those characteristics, together with results of former research conducted on its success, makes Douglas fir suitable for establishment of new cultures on non-forest land in Croatia.
As a result of all above mentioned information, part of this research was focused on analysis of Douglas fir provenances success 40, 42 and 45 years after culture establishment on three different localities of continental part of Croatia. Research on Douglas fir growth success was conducted in the 40th year after trial establishment on locality Durgutovica (Forest administration Vinkovci, Vinkovci forest office, ,) in the 42nd year on Slatki Potok locality (Forest administration Bjelovar, Veliki Grđevac forest office), and in the 45th year on the locality Mikleuška (Forest administration Zagreb, Kutina forest office). Trials were established in randomized block design in four repetitions. Trials include 23 different provenances in total (on all investigated localities – presented in Table 1). 19 provenances originate from areas of its natural distribution, mainly from lower altitudes (6 from Oregon, 3 from British Columbia and 10 from Washington). Four provenances originate from Europe, two of whichare from Croatia (Rovinj and Skrad), one from Bulgaria (Šipka) and one from Denmark (Hvidilde). Statistical analysis which has been conducted for all measured parameters (DBH, height, volume) on all localities showed statistically significant difference between provenances in the case of provenances on localities Durgutovica and Slatki Potok, while there is no difference between provenances on Mikleuška locality (presented in Tables 3, 4 and 5 for volume). Descriptive statistics for all localities, provenances and parameters is presented in Table 2.
Provenance with the highest average value of all analyzed parameters on locality Durgutovica is Hvidilde from Denmark (39,4 cm DBH, 27,7 m height, 1,68 m3 volume). In the case of volume, there is no statistically significant differences of this provenance and all other provenances except Šipka (1,45 m3) from Bulgaria and Tenino (1,41 m3) from Washington. Based on this result, those three provenances can be highlighted as the best provenances regarding volume on locality Durgutovica. According to statistical analysis of all analyzed parameters (DBH, height, volume) the poorest success on locality Durgutovica showed provenances Salmon Arm from British Columbia (26,1 cm DBH, 20,7 m height, 0,64 m3 volume) and Skrad from Croatia (29,7 cm DBH, 22,0 height, 0,80 m3 volume).
Provenance Elma from Washington, and generally speaking all provenances from Washington and European provenances from Denmark and Bulgaria showed the best success on Slatki Potok locality. On this locality the lowest average value of volume shows provenance Shady Cove (0,32 m3) from Oregon, which statistically differs from all provenances except provenance Salmon Arm (0,33 m3) from British Columbia. Those two provenances are excluded as the worst on this locality according to all analyzed parameters. The lowest DBH values belong to provenances from British Columbia and Oregon. 95 % confidence intervals for DBH on this locality are presented on Figure 1.
For volume value on locality Mikleuška it is determined that there is no statistically significant difference among four existing provenances (Cortage Grove-Oregon; Centralia-Washington; Cascadia-Oregon and Ashland-Oregon). 95 % confidence intervals for volume on this locality are presented in Figure 2.
On the basis of presented results we conclude that provenances with the best success for all localities are those which originate from lower altitudes (0-300 m a. s. l.)of The State of Washington (Elma, Tenino) and Europe (Hvidilde from Denmark and Šipka from Bulgaria). As those provenances showed the best success in continental part of Croatia we recommend that they should be used for establishment of new cultures in Croatia.
High production and wood quality together with wide range of ecological conditions places Douglas fir on significant position for new forest culture establishment in Croatia. New scientific knowledge highlights its significance in the scope of climate changes where it is recognized as species of beneficial biological properties.
This project was conducted under auspices of “Hrvatske šume” Ltd., so we would like to use this opportunity to express our sincere thanks for financial help as well as to thank all employees of forest and administration offices for their immense help.
Keywords
Douglas fir; forest cultures; success; provenance; Croatia
Hrčak ID:
72327
URI
Publication date:
14.10.2011.
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