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HR  EN   



Scientific-technical and professional journal
of Croatia Forestry Society
                         Issued continously since 1877.
       First issue of this web edition start with number 1-2/2008.
   ISSN No.: 1846-9140              UDC 630*https://doi.org/10.31298/sl

Portal of scientific
journals of Croatia
   Issued by: Croatian Forestry Society

   Address: Trg Mažuranića 11, HR-10000 Zagreb, Croatia
   Phone/fax: ++385 1 4828477
   e-mail: urednistvo@sumari.hr
   Editor in Chief: Josip Margaletić

Uredništvo   5
Is the profession or the system to blame?      
Last year the Croatian Parliament passed a new Forest Act (Official Gazette 68/2018), which came into effect on August 4th, 2018. We discussed the new Forest Act in this column in Forestry Journal 7-8/2018, where we expressed our opinion and reiterated our objections, but they were generally ignored. In the light of mostly negative opinions about forestry and the forestry profession in the media, the question in the headline becomes understandable. Whether there is truth in criticisms of the transparent or non-transparent way in which the company Croatian Forests Ltd does business is not on us to decide - there are institutions responsible for such issues. However, we shall mention in brief several of the articles from the new Forest Act and the Regulations that prescribe how to manage forests.   
According to article 2 (3) of the Forest Act, the Government of the Republic of Croatia manages forests and forest land and follows, among other things, “the principle of efficient management of forests and forest land in order to ensure the fulfilment of current and future ecological, economic and social functions on the local, national and global level, being in public interest, by taking into account the socio-economic importance of forests and forest land of the Republic of Croatia” ...”to do so, these activities must be in accordance with public interests ... and all together must be based on the principle of sustainable management of the natural resource.” The principle of sustainable management, according to article 3 (3) is fulfilled with “an efficient use of resources, whereby the contribution of forests, the forestry sector and forest-related sectors to rural development, growth and creating work places is optimized.”
Do we respect the regulations and principles, and if we do, to what extent? We shall only highlight a problem, and leave it to the readers to influence the finding of a solution. For example, do we use all forest resources efficiently? In the case of biomass as an energy source, the contracts which Croatian Forests Ltd recently cancelled, which is praiseworthy, were very profitable for private pockets, but whether they were equally profitable for the society is another question. What is the real goal of management according to the principle of sustainability? Will there be any sanctions for those who did not use cheap energy sources optimally (to generate electricity and heating) and did not respect contracts, as well as for those who signed these contracts? Take, for example, wood assortments as raw material to be improved with added value: despite the fact that several wood processing companies publicly confessed that wood assortments were sold at prices that were below market value, insistence on non-market business practices continues. They say that supply (which is limited by annual increment of wood mass) is up to three times lower than demand (which, using the logic of economics, should lead to an increase in prices), but also that cheaply obtained wood raw material is mostly “improved for export” only through primary wood processing. If wood as raw material participates in the manufacture of furniture with 17 % of the value on average, then it is not hard to conclude that by exporting “such minimally improved” raw material we export work places both in the wood industry and in the auxiliary industries (glues, dyes and varnishes, and similar). Why do all wood processing subjects want their own sawmills, and where is the sawn timber stock market which would supply the final processing companies? As silviculturalists and forest planners we ask ourselves what use are all silvicultural and planning activities and costs (cleaning, tending, thinning, establishing stands, protecting, and others, geared to favouring trees - bearers of production and classifying them by quality into wood assortments pursuant to the Regulations on Forest Planning), if the goal of production is to obtain the highest quality of wood assortments, which are then devalued with non-market prices? It is an indubitable fact that such prices generate high profit but minimal added value. Add to this the relatively poorly educated work labour (why should they need engineers?) and you get the non-optimal use of wood assortments. This is what we call squandering the national wealth. Low profits also jeopardize the optimal fulfilment of the ecological and social function of forests, which is estimated to be several times higher than the production of wood mass. If the profession has managed forests for over 250 years on the principles of sustainable management and has succeeded in preserving the optimal structure and quality of Croatian forests despite groundless opinions of the amateurs from the “Green Cadre” and others, including some protectors, we have an answer to the question in the headline.
Editorial Board

Marijana Žunić, Krunoslav Teslak  UDK 630* 923 + 94 (001)
Constraining factors of activities in Croatian forest estates – MIMIC model      
The purpose of this paper was to determine the share of active and inactive forest owners in Croatia and to identify potential causes for underuse of wood resources and their most important predictors based on inactive forest owners sample. We interviewed 1007 randomly selected forest owners on Croatian territory with a telephone survey. Of the total sample, 60% of forest owners believe that they efficiently manage their forests while 40% are inactive (Table 1). In order to determine the most important reasons and causes for inactive forest owners not cutting more, additional questions were asked. They were provided by 19 statements describing possible reasons for underuse of wood resources. Then, on Likert’s scale from 1 (not important at all) to 5 (very important) they expressed their level of agreement with a particular statement (Table 2). The statements were condensed into three dimensions by explanatory factor analysis with eigenvalue approach. Factors were interpreted as: (1) factor of qualifications and knowledge constraints, (2) factor of passiveness and forest conservation and (3)
factor of physical constraints (Table 2). Statistically acceptable model was established by confirmatory factor analysis approach (Figure 2). The pronounced processes of structural changes in forest ownership composition, as well as in socio-demographic and forest property characteristics, are evident across Europe consequently influencing the intensity of private forest management. Within the aforementioned, we used gender, age, education, working status, the distance between the forest and the place of residence, the size of the settlement and the knowledge of forest property boundary lines as independent variables for management constraining factors model construction (Figure 1). Socio-demographic and forest property characteristics have been modeled with the extracted management constraining factors by applying a Multiple Indicators Multiple Causes (MIMIC) model (Figure 3). MIMIC model revealed that gender, age, and lack of boundary lines knowledge were the most important predictors for management constraining factors (Table 4). The notable part of forest owners in Croatia do not manage their forests because of insufficient knowledge and qualifications.

Key words: private forest owners; management constraining factors; inactive forest owners; socio-demographic changes; MIMIC model

    ŽUNIĆ, Marijana    ŠL
    TESLAK, Krunoslav    ŠL
Luka Kasumović, Ake Lindelöw, Boris Hrašovec  UDK 630* 453 + 153 (001)
Overwintering strategy of Ips typographus L. (Coleoptera, Curculionidae, Scolytinae) in Croatian spruce forests on lowest elevation      
Better understanding of overwintering strategy in Ips typographus is crucial in planning of sanitation felling as hot spots recovery measure. Bark and needle litter are present as overwintering niches within the species. At the lowest elevation (500 m a. s. l.) in spruce stands 85 % of beetles overwinter under the bark. Overwintering behavior is elevation adaptable, and portion of beetles which overwinters under the bark of attacked trees increase with decreasing of elevation. The results suggest presence of high plasticity within the species which is well adaptable to changeable habitat and temperature conditions. High in the mountains sanitation felling need to be implemented early in autumn before beetles end the development, while at lower elevations a good result can be achieved with felling early in spring before the start of new generation. During the winter bark peels off the dense attacked tress very often and changes the beetle ratio between niches. This fact needs to be considered in planning of sanitation felling early in spring before fly period of I. typographus.

Key words: bark beetles; overwintering niches; predators; ecological plasticity; temperature; felling

    KASUMOVIĆ, Luka    ŠL
    Ake Lindelöw  
    HRAŠOVEC, Boris      ŠL
Dalibor Ballian, Emir Lizdo, Faruk Bogunić  UDK 630* 587 (001)
Analysis of differences of growth and phenology of provenances of Scots pine (Pinus sylvestris L.) in provenance experiment at Kupres (Bosnia and Herzegovina)      
Analysis of differences of growth and phenology of provenances of Scots pine (Pinus sylvestris) in provenance experiment at Kupres (Bosnia and Herzegovina)
In this paper, 15 European provenance of Scot pines have been analyzed in an international experiment at Kupres. The experiment was established during the spring of 2012 with plants of two years old (2 + 0). A total of 1,800 seedlings of ordinary Scot pine were planted in the experimental design of a casual block system adapted to the terrain, 15 provenances in five repetitions (5 x 36 seedlings). The experiment is made up of ten European countries: Austria (Traisen, Rein, Sistrans), Bosnia and Herzegovina (Bugojno), Ukraine (Ivano Frankivsk), Slovakia (Hanusovce), Romania (Sacueini), Norway (Narvik, Arnes), Germany (Teisendorf , Trippstadt), Poland (Raciane - Nida) and Italy (Ca del Lupo, Fenestrelle, Piani - Valda). The results of morphological and physiological researches relate to differences in survival, height, root neck diameter, and spring phenomenon of bud opening. The total number of seedlings measured is 1830, with the percentage of survival in the year 2017 being 67.70%, and ranging from 35.50% (Italy I1) to 87.70% (Austria A1). Descriptive analysis of the diameter of the root neck was found to have the highest mean diameter of Austria A1 (4.07 cm). The lowest value of the average diameter of the root neck has plants originating in Norway N1 (1.19 cm), root diameter values ranged from 0.30 cm to Norway N1, which is the minimum of 9.30 cm for Austria A1 which represents the maximum when it comes to the average diameter of the neck of the root.
With an average height of 116.26 cm, the provenance of Poland P1 shows the highest average value for altitude, while the plants from Norway N1 have the lowest average value for a height of 40.52 cm.
All studies have shown a variance analysis that statistically significant differences between investigated provenances are present, as confirmed by Duncan’s test.
On the basis of the analysis carried out, it can be concluded that on the basis of the height of the only N1 and Italy I1 provenances, they are separated into separate groups because they have noticeable and far least average values of the seedlings height. On the other hand, as far as diameter on the root of the root can be seen only the N1 Norway proves itself into a separate group with by far the smallest mean diameter.
Based on phenological observations, there is variability between all provenances. Differences in movement, duration and end of individual phenomena have been established. As a start of ordinary Scot pine tree vegetation in the international experiment on Kupres can be taken on April 26 because in the three provenances this day the opening of the buds began. In the other 12 provenances the opening of the buds began on May 3, and on 21 June it was noted that the plants in all fifteen investigated the origins have come to the final stage, that is, they have completely formed needles of green color.
The first results of the phenological observations show that these studies should continue to determine the overall genetic diversity of ordinary wrinkles, to determine the success and genetic variability of provenances, as well as the behavior and success of different provenances at a given locality.
Ordinary pine is genetically differentiated into ecological and vegetation areas, and shows different morphological and physiological characteristics from different areas. This indicates the separation of northern provenances.
The research results obtained at the early juvenile stage are incomplete, often burdened with various disadvantages, and very often different from those obtained at later stages, and such research has to be carried out in continuity.

Key words: Scot pine (Pinus sylvestris L.); provenance; survival; root neck diameter; height; pheno­logy.

    Dalibor Ballian  
    Emir Lizdo  
    Faruk Bogunić  
Tihana Vilović, Suzana Buzjak, Nenad Buzjak  UDK 630*111 + 164 (001)
Floristic and microclimatic features of the Sovljak doline (Mt. Velika Kapela, Croatia)      
The relation between floristic composition, microclimate and geomorphology of a large-sized karst doline was analysed in the area of the Sovljak doline located on the Mt. Velika Kapela. Habitat conditions in various parts of the doline, due to its morphology, were described in this work. Geomorphological observations, microclimatic measurements (including air temperature, relative humidity and dew point temperature data) and flora inventory were carried out. Ellenberg’s indicator values, life forms, chorological and taxonomical analyses were performed, as well as the analysis of habitat similarity. The doline slopes (northern and southern) appeared to offer different habitat conditions than its bottom, due to their morphological and microclimatic differences, which resulted in high taxa variability along short distances in the doline. Furthermore, the presence of temperature inversion promoted the development of the vegetation inversion, which is common in such large dolines.

Key words: microclimate; geomorphology; flora; Ellenberg’s indicator values; vegetation inversion

    Tihana Vilović  
    Suzana Buzjak  
    Nenad Buzjak  
Ali Kemal Özbayram  UDK 630* 561+ 242 (001)
Diameter increment distribution along the stem of narrow-leaved ash in response to thinning intensity      
Narrow-leaved ash (NLA, Fraxinus angustifolia) is an important tree species due to its rapid development and valuable wood. In the pure NLA plantations in Turkey, little is known about the effects of thinning intensity on the diameter increment of different parts of the tree stem. In 2005, a thinning experiment with three thinning intensities (control: 0%; moderate: 19%; heavy: 28% of basal area removed) was established in an NLA plantation in Sakarya, Turkey. Seven years after thinning, a total of 25 sample trees representing dominant and co-dominant trees were felled, and cross-sectional stem samples were taken for analysis. The diameter at breast height (d1.30) and d1.30 increments of the co-dominant trees with the moderate and heavy treatments were similar to each other and greater than in the controls. The seven-year d1.30 increments of the dominant trees in the heavy-treatment plot were approximately 20% greater than in the other treatments plots. The highest diameter increments in both dominant and co-dominant trees for all treatments were determined at the 0.30 m and 17.30 m section heights. The sample tree diameter increments of between 1.30 m and 13.30 m were similar within their classes. In conclusion, heavy-intensity thinning of up to 28% did not cause tapering in the NLA plantation stems, and thus, heavy thinning can be recommended for NLA trees.

Key words: Narrow-leaved ash; Fraxinus angustifolia; thinning; stem form

    Ali Kemal Özbayram  
Muberra Pulatkan, Asena Sule Kamber  UDK 630* 232.3 (001)
Provenance variation in germination and seedling growth of Rhododendron ponticum L.      
Rhododendron ponticum is a popular shrubby plant in landscape architecture planting designs. It is especially effective when used in large groups, due to its form, foliage and flower aesthetics, as well as its functional properties. The plant is indigenous tomany mountainous and forested areas of different elevations. In the present study, the germination success of Rhododendron ponticum seeds obtained from three different provenances in NE Turkey: Zafanos (39º46’N, 40º56’E, 592m), Maçka (39º39’N, 40º41’E, 1234m) and Zigana (39º24’N, 40º39’E, 1744m) was investigated under greenhouse conditions (25 ± 2ºC, 70 ± 2% Humidity). After germination, seedling sizes and root length were determined. The highest germination rate (78.91%) was obtained with the seeds collected from Maçka (1234m). The development of the seedlings demonstrated that the greatest height and root length values were obtained with the seedlings collected at the Zafonos site (592m).It was found that germination success was not effectively correlated with the rate of seedling development.

Key words: Rhododendron ponticum; germination; seedling growth; provenance variation

    Muberra Pulatkan  
    Asena Sule Kamber  
Igor Anić  UDK 630* 902 + 945.3
The importance of forestry education and science at the University of Zagreb for the development of Croatian forestry      
This paper explores the influence of higher forestry education and forestry science at the Faculty of Forestry of the University of Zagreb on the formation and preservation of forest wealth in the Republic of Croatia during the past 120 years as the basic, authentic, self-renewable, biologically diverse and distinctly natural element. In order to do so, we shall provide a survey of some significant achievements of the faculty and its distinguished professors by citing examples of important textbooks and scientific papers.
In the year 2018, the Faculty of Forestry in Zagreb marked the 120th anniversary of its establishment. It was on October 20th, 1898, that the Academy of Forestry was founded within the University of Zagreb as the first higher forestry institution in Croatia and in the south-east of Europe. 
The continuity of higher forestry education at the University of Zagreb has been retained to date through the periods of activity of the Academy of Forestry (1898 - 1919), the Faculty of Agriculture and Forestry (1919-1946), the Agricultural-Forestry Faculty (1946 - 1960) and the Faculty of Forestry (1960 - to date).
Three characteristic periods can be singled out in the development of forestry education and science at the Faculty of Forestry in Zagreb in the course of 120 years: the first half of the 20th century, the second half of the 20th century and the first half of the 21st century.
The first half of the 20th century witnessed a surge in the Croatian forestry, which can primarily be attributed to the development of higher forestry education and science at the Academy of Forestry and the Faculty of Agriculture and Forestry of the University of Zagreb. Among the most important contributions of university forestry education and science in Croatia are the establishment of the Zagreb School of Silviculture and the beginnings of organized and systematic scientific research in forestry.
The second half of the 20th century is characterized by the blossoming of higher forestry education and science in Croatia, which had a direct impact on the condition of forests and the development of practical forestry. During this period, the Croatian forestry, science and practice became an outstanding example of mutual cooperation and powerful development, which brought about an improvement in the condition of forests in Croatia as a whole. The forestry practice firmly adhered to the principles of the Zagreb School of Silviculture, an orientation towards natural regeneration, natural stand structure, and natural, diverse and stable forests.
This trend has continued in the 21st century. The new age has given rise to vast changes and challenges in higher forestry education and science. The crisis of forestry, which has gradually been evolving over the past fifteen years, has had its repercussions on the basic activity of the Faculty: higher education and science. Today, the Faculty of Forestry is confronted with two serious challenges: lesser interest of young people in studying and a reduced intensity and scope of scientific research in forest ecosystems. 
There are no objective reasons for either of the above, however. Forests are the most widespread and the most important natural wealth in the continental part of the Republic of Croatia. There are currently a large number of job openings in forestry and urban forestry, as well as in nature and environment protection, and this trend will continue to rise in the future. The Croatian forest ecosystems are facing growing numbers of challenges and problems. On the other hand, there are fewer and fewer workers in forestry. In view of this, there is no reason for crisis in one of the most natural and oldest studies at the University of Zagreb. On the contrary, forestry experts have splendid prospects in today’s ecological, economic and social conditions. The task of the Faculty is to adjust itself and its basic products, experts in the management of forest ecosystems of the Republic of Croatia, to new challenges.
Forestry practice and forestry science must work together, just as they have done throughout the long forestry history. Only be doing so will their development be ensured in accordance with the definition: forestry is a science, profession and art of managing and preserving forest ecosystems for the permanent benefit of man, society, environment and economy.

Key words: Croatian forestry; history of forestry; University of Zagreb; Faculty of Forestry; forestry education; Zagreb School of Silviculture

    ANIĆ, Igor      ŠL