|REPETITIO EST MATER STUDIORUM
The old Latin saying „Repetition is the mother of all learning“ is true on principle, but the question is how many times something should be repeated to a person in order for this person to grasp it and master it. This depends on the will of an individual or of the society, but also on the person’s level of professional capacity in a certain segment. If we ask ourselves which of these is true for our society – experience tells us it is both. Which topics should we repeat without our readership objecting that they have already been dealt with either directly or indirectly? In the same way in which repetition is the mother of all study, the Strategy, which is based on the factual state, can also be said to be the „mother“ of future planning for the State and its segments. The need to plan and draw up a general Strategy, including in particular the Strategy of Forestry Development, was discussed in this column of the Forestry Journal on several occasions, e.g. in No 4-5-/2011 and No 3-4/2016, when we quoted the words of the then minister that „the deadline for drawing up the strategy of agriculture and food industry, forestry and wood processing was the end of 2016“. The deadline is long past but the Strategy has not been made. Whether it is being developed and by whom is not known to us; what we know is that the Croatian Forestry Association does not have its representative in the Commission on Strategy Development. We believe that the topics discussed in the editorials of the Forestry Journal volumes mentioned above, the several articles in the column Challenges and Conflicts, as well as the article of the Management Board of the Croatian Forestry Association in No 11-12/2015, provide „good material“ for the Strategy. Such an important document should be developed at the highest professional-scientific level rather than at the „clerical“ one. An order/priority should be made in making the documents and in their compatibility so at to avoid parts of one document to counteract others. Every document should be tested in practice in order to remove irregularities and even criminal actions and should contain measures and competences of dealing with and penalizing such actions. Likewise, the documents should contain „instructions“ for overcoming unforeseen circumstances caused by biotic and abiotic agents. The case of the catastrophic ice break in Gorski Kotar warns us of the need to undertake an exceptional revision of management plans using professional methods of restoring the damage, rather than approaching such circumstances in an unplanned and chaotic manner. Inactivity and lack of appropriate measures can also be seen in, for example, the non-reforestation of burned areas, the main agent of future erosions, or in the disharmony and anarchy of managing private forests. Article 52 of the Constitution of the Republic of Croatia, which protects forests and classifies them into natural resources of particular interest for the Republic, does not refer only to state forests, but to all forests irrespectively of ownership. Consequently, all forests should be treated and supervised in an equal manner.
With reference to the order of activities, it seems illogical to pass a new Law on Forests or the Law on the Agricultural (again the question: why not the Forestry) Advisory Service and other documents before making the Development Strategy, which is the core document for all the other laws and by-laws. As for the Law on Agricultural Advisory Service currently under way, we stress that the problem is not only in the omission of forestry from the name of the Law, but more importantly, in the vagueness and non-comprehensiveness of the problems in particular articles, which should be re-examined. The need for further upgrades illustrates the complexity of the matter we are dealing with, and requires appropriate solutions both in the main and in the accompanying documents. After all, these documents provide a basis for the management of forests on the principles of sustainability.
|IZVORNI ZNANSTVENI ČLANCI
|Damir Ugarković, Kristina Pleša
| UDK 630* 114 + 228 (001)
|COMPARISON BETWEEN TREE DIEBACK OF PEDUNCULATE OAK AND NARROW-LEAVED ASH IN RELATION TO ECOLOGICAL CONSTITUTION OF SPECIES
The pedunculate oak (Quercus robur L.) and narrow-leaved ash (Fraxinus angustifolia Vahl) tree dieback phenomenon presents an economic as well as ecologic problem. Factors that cause tree dieback can be biotic, biotopic (within habitat) and structural (within stand). In managed forests, the volume of dead trees or volume
of trees cut in a sanitation harvests are most often used to show the intensity of tree dieback, and may also be used as an indicator of the stands condition (Capecki, 1981).Every species has its own ecological niche. Forest tree species have varying reactions to changes in environmental factors, to stress and ultimately to dying. The study was conducted in „Zelenika” management unit in Posavina. The aims of the study were to establish pedunculate oak and narrow-leaved ash tree dieback dynamics, to research the influence of biotopic and structural factors on dieback intensity and to compare dieback intensities according to the stand age class and microrelief. For analysis were climatic data for Novska meteorological station, water level data of Novska watercourse, and groundwater level data from „Zelenika” piezometric station were used. Dry years and dry periods, and wet years and wet periods, were determined using the percentile method and the Walter climate diagrams.
Growing volume of withered pedunculate oak and ash trees, as well as structural factors data(stand structure elements) were collected from the O-2 form of the Forest management plan. Dieback intensities were calculated on the basis of growing volume of the withered trees per area unit ratio. The intensity of tree death was shown in absolute numbers, as m3/ha (Siwecki et al. 1998).
Considering the average change rate, dieback intensities of pedunculate oak and narrow-leaved ash tree are increasing. The highest dieback intensities for both forest species were found in the VI age class (Figure 2). On the basis of the conducted research, it can be concluded that climatic, hydrological and structural factors influence pedunculate oak and narrow-leaved ash tree dieback.
Pedunculate oak is more sensitive to climatic elements in comparison to narrow-leaved ash tree. Frequent dry years significantly affected the dying of these two species, which can both be considered hydrophytes in terms of their ecological demand for water. The results of this study showed that narrow-leaved ash was more vulnerable to drought than pedunculate oak.
Drought and rain periods also significantly influence tree dieback (table 5). The effect of dry periods on the dieback of these two species was greater in relation to the lack of wet periods in these lowland forests. The decrease of mid and minimal water levels of watercourse influenced pedunculate oak dieback, while a decrease of maximum watercourse water levels influenced narrow-leaved ash tree dieback (table 6). Groundwater level decrease in deeper layers of pedosphere had asignificant influence on tree dieback intensities (table 7). It was revealed that all structural factors influence pedunculate oak dieback, while narrow-leaved ash tree dieback was influenced only by stocking and tree number increase in a stand (table 8).The dieback of pedunculate oak was higher in older stands. No correlation was detected between the dieback of narrow-leafed ash and stand age.
Key words: pedunculate oak; narrow-leaved ash tree; dieback; biotopic factors; structural factors
UGARKOVIĆ, Damir ŠL
|Ivan Perković, Nikola Pernar, Darko Bakšić, Nikola Glamočlija, Vibor Roje
| UDK 630* 114 (001)
|THE EFFECT OF PARENT MATERIAL ON PHYSICAL AND MINERAL SOIL PROPERTIES ON MEDVEDNICA NATURE PARK
The highly complex lithological structure as well as topographic characteristics of the Medvednica area are responsible for its profound vegetational, micro-climatic and pedophysiographic diversity. In view of the quality of the original soil-forming material, the first place is taken by rocks and their detritus which directly govern soil physical composition. The best indicators of soil physical composition are its depth, colour, skeletal nature, particle size distribution, soil density, density of soil solid phase, total porosity, water capacity, air capacity, structure and hydraulic properties. On Medvednica, these vary greatly and play the main role in defining soil quality. The success of ecosystem management depends on the knowledge of the above factors. The goal of this research is to determine how the lithological base, or parent material, primarily affects physical (horizon thickness, profile depth, skelet proportion, soil texture, soil structure) and mineral soil properties.
A total of 80 pedological profiles were opened in the Medvednica Nature Park area and evenly distributed so as to comprise all the representative lithological units. Samples of physically altered soils were taken from genetic horizons, as well as a fragment of rock, i.e. parent material, for the purpose of determining the lithological rock affiliation. Soil samples has been analayzed in the humus-accumulative (A horizon) and first under mineral horizon (mostly B horizon). The differences between the topsoil humus-accumulative and B horizon were statistically analyzed per lithological units. The samples were prepared (ISO 11464 2006) and analyzed in the laboratories of the Faculty of Forestry of the University of Zagreb and at the Croatian
Geological Institute in Zagreb. According to FAO (2006), the following was determined in situ: the proportion of skelet per genetic horizon, horizon thicknesses and total profile depth. Laboratory analyses of the samples taken from genetic horizons included the particle size distribution according to ISO 11277:2009, stability of structural microaggregates according to Pernar et al. (2013) and mineral soil composition (XRD) using the X-ray diffraction method on X-ray diffractrometer X’Pert PRO MPD.
For the needs of statistical analysis, parent material was divided into six characteristic units, leaning in part on the classification of Halamić et al. (2001) used during geochemical research of stream sediments on Medvednica. The lithological unit LIT1 is represented by metamorphic rocks, predominantly greenschists, muscovite chlorite and quartz-muscovite schists. The lithological unit LIT2 is represented by metamorphic rocks, predominantly phyllites. The lithological unit LIT3 consists of igneous rocks, predominantly diabases and spilites. The lithological unit LIT4 are Mesozoic clastic rocks of Lower Cretaceous age, and comprise sandstones, siltites and shales. The lithological unit LIT5 consists of Mesozoic and Tertiary clastic rocks dominantly represented by marls. LIT6 is made up of Tertiary carbonate rocks represented by lithotamnic limestones together with clay limestones (Figure 1).
Statistical analysis was performed with Statistica 7 software. Descriptive statistics was made for all the analyzed variables, including the number of samples, arithmetic means and standard deviation. Differences between the analyzed variables by lithological units were tested with a one-way analysis of variance (ANOVA), on condition that the assumption of homogeneity of variance was satisfied. For those variables in which the test of homogeneity of variance was not satisfied, the Kruskal-Wallis non-parametric test was used. Type I error (a) of 5 % was considered statistically significant.
The following soil types were identified in the opened pedological profiles: dystric cambisol, eutric cambisol, calcaric cambisol, stagnosol, regosol and luvisol (the percentage ratio by representation is 62 % – 19 % – 10 % – 4 % – 3 % – 2 %).
Based on the comparison of soils formed in six different lithological units, it can be concluded that physical and mineral soil properties depending on type of litological units. Silty to clay loam is the most represented textural class in Medvednica Nature Park. It was found on metamorphic rocks above greenschist and phyllite, igneous rocks, sandstones and marls, whereas on easily weathered limestones the textural class ranges from silty clay to clay. The analysis of particle size distribution (content of individual fractions) showed that the profiles developed on silicate lithological parent material have on average higher sand content compared to the profiles developed on carbonate rocks, which is conditioned by the manner of parent rock weathering. Higher clay content above easily weathered limestones eventually led to variability of the textural class in relation to other lithological units. In all the investigated lithological units in terms of structural microaggregate stability, the soils in Medvednica Nature Park manifest highly stable microaggregates. In relation to the B-horizon, the humus-accumulative horizon revealed higher stability of structural microaggregates, which can be attributed to higher content of organic matter in the topsoil horizon. The soils above igneous and metamorphic rocks have significantly lower content of the mineral quartz and higher content of the minerals chlorite and feldspar in relation to the soil above sedimentary rocks. There was no difference in muscovite/illite contents in lithological substrates. Soil was the deepest above marl rocks and the shallowest above dolomitised limestones, which is primarily conditioned by the manner of parent material weathering.
Our research highlights all the complexity and heterogeneity of the geological-lithological structure of Medvednica. In combination with other pedogenetic factors, it manifests even higher soil heterogeneity, which eventually causes problems in the processing and interpretation of the results.
This research provides reference data on physical and mineral properties of soils in Medvednica Nature Park in the most represented lithological units. However, these data should be taken with caution and should be compared with the results of other similar studies, since the same lithological parent material may give rise to the formation of soils of different taxonomic affiliation, depending on the changes in the constellation of other pedogenetic factors (climate, vegetation, relief).
Key words: parent material; lithological unit; physical and mineral soil properties; Medvednica Nature Park
PERKOVIĆ, Ivan ŠL
PERNAR, Nikola ŠL
BAKŠIĆ, Darko ŠL
|Nera Bakšić, Darko Bakšić
| UDK 630* 262+114.2 (001)
|FOREST FLOOR FUEL LOADS AND CARBON STOCKS IN ALEPPO PINE FORESTS ON ISLAND OF MLJET
From the aspect of forest fires, the forest floor is considered a potential fuel: however, in the context of current global climate change it plays an exceptionally important role in the exchange of matter and energy and of carbon in particular. For this reason, forest floor data are traditionally used in forest fire danger rating and in fire behavior and spread models. More recently they have also been used to estimate emissions of carbon and other gasses and to gasses and to quantify carbon stocks. The main objectives of this study are to a) determine the depth, bulk density and fuel load for each forest floor horizon with the associated carbon stock in Aleppo pine stands and b) develop regression models that relate forest floor depth to forest floor fuel load and forest floor depth to forest floor carbon stock, for horizons and for the entire forest floor. Forest floor sampling was carried out in Aleppo pine stands situated in Mljet National Park, per 0-50 cm, 100-150 cm and 200-250 cm circumference classes. Each forest floor horizon was sampled separately, and fuel load and organic carbon content were determined for each horizon. Our results suggest that Aleppo pine stands contain significant carbon stocks in the forest floor, but relations and processes that influence these stocks have not been sufficiently studied. This is supported by significantly greater forest floor depths and fuel loads in Aleppo pine stands than previously reported. Thus, the mean depth of forest floor of 9.0 cm, fuel load of 94.3 Mg ha-1, and carbon stock of 37 Mg
C ha–1 were determined under trees with a 200-250 cm circumference class. Regression analysis revealed a statistically significant relationship between depth and fuel load and between depth and carbon stock. Regression models were given for the OL horizon, the OF1,OF2 and OH horizons, as well as for the entire forest floor. Our results have practical value as they will allow reliable quantifications of forest floor fuel loads and carbon stocks in Aleppo pine stands by using easily measurable fuel characteristic, which can then be applied in the aforementioned models. The forest fuel inventory provides the basis for parameterization and operational use of a number of forest resource management applications in Croatia.
Key words: Aleppo pine; forest floor; fuel load; carbon stocks
BAKŠIĆ, Darko ŠL
|Zeynep Yavuz, Mustafa Yilmaz
| UDK 630 + 232.3 (001)
|SEED DORMANCY AND CONE AND SEED MORPHOLOGY OF SYRIAN JUNIPER (Juniperus drupacea Labill.) IN THE EASTERN MEDITERRANEAN REGION OF TURKEY
Syrian juniper, Juniperus drupacea Labill., is an Eastern Mediterranean tree species which belongs to the Cupressaceae family and Juniperoidae sub-family. The current geographical range of J. drupacea covers the southern parts of the Peloponnese in Greece, the southern parts of Asia Minor and the mountains of Syria and Lebanon. The main part of the species range in Turkey is divided into several centres the most important being located in the Taurus, Anti-Taurus and Amanos mountains. It is a dioecious tree, with conical crown, that reaches 10-20 (40) m in height. The fleshy cones are ovoid to globose, 20-25 mm in diameter, brownish-purple or bluish-black, glaucosus and pruniose when ripe in the second year. They mostly have 3 seeds forming a characteristic drupe-like stone. The natural regeneration of Syrian juniper is very difficult because of animal consumption, grazing and the united seeds into the woody structure. This study was carried out to determine the seed and cone morphology and seed physiology of Syrian juniper, Juniperus drupacea Labill., from three provenances (Kahramanmaraş, Mersin, Adana) in the Eastern Mediterranean region of Turkey. In total 11 morphological traits were measured. The average cone length, cone diameter, and cone weight were 22.49 mm, 20.86 mm and 4.659 g, respectively. The average seed length, width, thickness, weight and pulp weight were 10.07 mm, 3.30 mm, 2.77 mm 0.045 g and 2.220 g in order. After morphological analysis, a series of experiments was conducted to identify the best stratification treatment for breaking dormancy in Syrian juniper seeds. The highest germination percentage was obtained after warm and cold stratification (80.7%). The seeds prechilled 8 weeks and soaked 500 ppm GA3 also demonstrated high germination percentage. The current study demonstrated that J. drupacea seeds has morphophysiological dormancy.
Key words: Juniperus drupacea; cone and seed morphology; seed dormancy
|Ivica Tikvić, Damir Ugarković, Željko Zečić, Patrik Korijan, Davor Gašpar
| UDK 630* 89
|Truffles in Croatia: natural distribution and ecological problems
Truffles are natural symbiotic fungi on forest trees which develop in most forest ecosystems in Croatia. They draw special attention due to their gastronomic properties and high price. In Croatia truffles are most intensively collected in forests of Istria, even though they are known to exist also in other mediterranean and continental parts of Croatia up to 600 m above sea level. This paper presents new localities where truffles have been discovered in Croatia, as well as the data about truffle distribution in Europe. The truffle management in forest ecosystems of Croatia is not fully organized. The issues of sustainable truffle management in forests are the changing of ecological conditions, intensive and unorganized truffle collection and decrease of tree vitality. This paper discusses the most important unfavorable ecological and other factors for truffle development. Also, possibilities for improvement of truffle production in forests and truffle farms are presented, with special attention to habitat management.
Key words: truffles; new truffle locality; sustainable truffle management
TIKVIĆ, Ivica ŠL
UGARKOVIĆ, Damir ŠL
ZEČIĆ, Željko ŠL
|Nediljko Landeka, Martina Podnar
| UDK 630* 453
|RECORD OF ALIEN Cinara (Cinara) cedri, (HEMIPTERA; APHIDIDAE) IN ISTRIA, CROATIA
Aphid species Cinara cedri (Mimeur, 1936), the unusual species of the Croatian aphid fauna, was recorded in the area of Pula (Istria, Croatia) on October 23rd, 2012 (Figure 2,3). It was found in the southern part of the town on Cedrus libani tree. The species was identified by combined morphological and molecular approaches. Standardised fragment of the mitochondrial cytochrome c oxidase I gene (DNA barcode region) was used as a molecular marker. Molecular analysis supported morphological identification of specimens as Cinara cedri.
Phylogenetic analysis placed Pula specimens within highly supported, monophyletic Cinara cedri clade. In the overlaping region (629 bp) their sequences are identical to the sequence of Cinara cedri from China, while the pairwise genetic distance between them and 56 other Cinara species included in analysis were greater than 7.7 % (Figure 4 b). Identification through Barcode of Life Data Systems (BOLD) web platform (currently containing DNA barcode sequences of 99 species of genus Cinara), matched Pula specimens to Cinara cedri with 99.7 % probability of placement.
Monitoring conducted during the time period of 2013 – 2015 in the wider area has not revealed either new populations of this species or the population increment at the original location.
Key words: Aphididae; Cinara cedri; Pula; Croatia; alien species; DNA barcoding
|Tikvić, Ugarković, Peles, Knežić, Medunić-Orlić, Marinić, Butorac, Čmrlec, Koharević, Nazlić, Pavlinović, Špika, Tomić
| UDK 630* 272 + 901
|ASSESSMENT OF FOREST ECOSYSTEM SERVICES AND NON-MARKET FOREST FUNCTIONS IN PARK FOREST MARJAN SPLIT
Forest ecosystem services and forest functions have similar meaning with partial differences. Forest functions refer to forests’ purposes beneficial to people, while ecosystem services are results of forest functions and still present the benefits of ecosystems to people and environment. Ecosystem services cover all forest functions, whereas non-market forest functions are those which are used by all people. Park forest Marjan with its many ecosystems offers many services and benefits to the inhabitants of Split, park forest visitors and other organisms. Of the 300 ha area of park forest Marjan, forest ecosystems are most prevalent and account for 2/3 of the park forest area. In this paper, 28 forest ecosystem services of park forest Marjan were defined for the first time based on the international ecosystem services classification and other non-market forest function
classifications. Services were ranked by means of a questionnaire of stakeholders. The five most important services were the production of clean and fresh air, natural space for recreational activities, natural space for leisure, oxygen production and natural space for educational activities. Monetary value of the five most important services was assessed using several different estimation methods based on certain criteria and indicators. Estimated values of individual most important services ranged from 700 kuna to 77.000 kuna per ha per year. Total estimated value of those services amounted to 122.000 kuna per ha per year, that is, 24,4 million kuna per year for the 200 ha of forests in park forest Marjan. Furthermore, approximative monetary value assessment was performed for other 23 forest ecosystem services. As a result, the total estimated value of all 28 services was 708.000 kuna per ha per year, that is, around 141,6 million kuna per year for the 200 ha of forests in park forest Marjan. Obtained results were validated using assessment of non-market forest functions according to the management plan of park forest Marjan, assessment of non-market forest functions of mediterranean forests and the annual amount of non-market forest function fees, with estimated values ranging from 200 kuna to 402.000 kuna per ha per year. Monetary assessment of forest ecosystem services is key in the management and protection of ecosystems, as well as in reducing of adverse human influences on ecosystems and their services, which serve to the welfare of current and future generations.
Key words: forest ecosystem services; non-market forest functions; park forest Marjan; assessment of ecosystem services
TIKVIĆ, Ivica ŠL
UGARKOVIĆ, Damir ŠL
BUTORAC, Lukrecija ŠL