A provenance experiment of European beech (Fagus sylvatica L.) was established in Croatia in 1998 as part of an international network of beech provenance trials. Of the 36 provenances present in the trial, six were selected for the presentation of a new method for assessing their adaptability: easternmost (Ukraine UK-59), westernmost (France F-5), northernmost (Sweden S-23), two southernmost (Croatia, easternmost CR-3 and westernmost CR-18) and one central (Czech Republic CZ-51). The selection was made by choosing the minimal number of most distant provenances from the area of the natural distribution range of beech. Flushing as an indicator of physiological character was monitored in seven phenophases, which were recorded on seven dates during the years 2000 and 2001. The differences in entering phenophase 3 (indicating the very beginning of flushing when plant is most sensitive to frost) were analysed using a product limit estimator. The six analysed provenances may be classified into three different groups: early flushing (CR-3, CZ-51), intermediate flushing (CR-18, UK-59) and late flushing (F-5, S-23). The provenances were then ranked with Analytical Hierarchy Process in order to select the most adaptable one using the following criteria: survival, date entering phenophase 3 and mean height.

The main aim was to develop models for predicting diameter at breast height (DBH), merchantable tree volume (V), and aboveground biomass (AGB) of individual black pine (Pinus nigra Arn.) trees grown in Sub-Mediterranean Croatian pure even-aged forests, which will be suitable for remote sensing based forest inventories. In total, eight variables obtained from field measurement, existing database, and digital terrain model were candidates for independent variables in regression analysis. DBH, V, and AGB were modeled as linear function of each of the independent variables, and all possible linear combinations thereof. Goodness of fit of every model was then evaluated using R² statistic. Comparison between selected models showed that the variability of all dependent variables are explained best by models which include both crown diameter and tree height as independent variables with coefficients of determination of 0.83, 0.89, 0.82 for DBH, V, and AGB, respectively. Consequently, these models may be recommended as the most suited for DBH, V and AGB estimation of black pine trees grown in pure Sub-Mediterranean forest stands using high-resolution aerial images or high-density airborne laser scanning data. This assumption should be further validated by conducting remote sensing inventory and comparing the obtained results with field measurement results.

Decomposition is an important carbon flux that must be accounted for in estimates of forest ecosystem carbon balance. Aim of this research is to provide estimate of fine woody debris decomposition rates for different tree species and sample sizes also taking into account the influence of specific microsite meteorological conditions on decomposition rates. In this paper we present results of the first two years of the experiment designed to last six years. Study was conducted in managed lowland oak forest in central Croatia. Decomposition rates (k) of fine woody debris (diameter 0.5–7 cm) for four species (Querus robur L., Carpinut betulus L., Alnus glutinosa Gaernt., Fraxinus angustifolia L.) in four size classes were estimated using litter bag method and mass loss equation of Olson (1963). Overall average k in our study was 0.182 ± 0.011 year-1. Results indicate that decomposition rate is affected by the size of the debris, with the smallest diameter branches (<1 cm) decomposing is significantly faster (k = 0.260 ± 0.018, P <0.05) than the larger one. Tree species from which debris had originated also affected decomposition, although to a lesser extent, with hornbeam samples having significantly (P <0.05) higher average decomposition rate (0.229 ± 0.028), compared to that of ash samples (0.141 ± 0.022). Proportion of variability in k explained by variables ‘species’ and ‘size class’ was assessed with general linear model (R² = 0.644) also taking into account variables like soil temperature and soil water content. Sample size class explained 22.2%; species explained only 9.4%, while soil water content and temperature combined explained 32.8% of the variance of k. Rate constants obtained within this study might be useful in modelling ecosystem carbon balance for similar lowland forest ecosystems in Europe.

Iako se šumarstvo smatra tradicionalnom strukom i područjem znanosti, njegova važnost i značenje u današnjim prilikama povećane svijesti o klimatskim promjena i dobrobiti održivog razvoja prirodnih ekosustava svakim danom sve više raste. Suvremeni i ažurirani studijski programi neophodni su uvjet za primjereno obrazovanje stručnjaka za gospodarenje šumskim ekosustavima i proizvodima. Bolji uvid u studentsku socioekonomsku pozadinu i motivaciju za studij mogu poslužiti za unapređenje studijskih programa, kao i pomoć studentima u postizanju boljih rezultata. Provedeno je istraživanje radi usporedbe trajanja preddiplomskog studija i postignute prosječne ocjene s analizom čimbenika koji bi mogli na to utjecati. Proveden je upitnik među studentima (N=185) diplomskih studija Šumarskog fakulteta Sveučilišta u Zagrebu akademske godine 2016/2017. Analizom varijance testirane su razlike između prosječnih ocjena studija i trajanja studija. Za procjenu utjecaja čimbenika na trajanje studija provedena je višestruka linearna regresija. Približno trećina studenata dolazi iz Zagreba. Više od dvije trećine studenata na šumarskom odsjeku je završilo gimnaziju, dok su na drvnotehnološkom odsjeku dvije trećine studenata završile srednje strukovne škole. Prosječne ocjene i trajanje studija ne razlikuju se statistički značajno po studijskim programima ni po spolu. Prosječna ocjena studija i trajanje studija statistički su značajno negativno korelirani za sva tri studijska programa. Statistički značajni prediktor trajanja studija za sva tri studijska programa je prosječna ocjena studija. Za studij Šumarstvo dodatni prediktori za kraće studiranje su stipendija i osobna motivacija, dok su za studij drvne tehnologije spol (M), stipendija i završena srednja škola (gimnazija).

Coppicing has been neglected in recent decades leaving gaps in knowledge on silvicultural interventions, especially the long-term effects on coppices of South-East Europe. Thus, our work aims to define the long-term effects of thinning in sessile oak (Quercus petraea (Matt.) Liebl.) and European beech (Fagus sylvatica L.) sub-mountainous thermophilic low coppices in the Croatian Dinarides. The experiment includes two localities with thinning plots and control plots. Thinning was done in 2002 with 17.71% of wood volume removed in the European beech coppice and 26.09% in the sessile oak coppice. 1276 trees were marked, measured (DBH, tree height, number of stems per stump) and assessed for vitality, origin and six silvicultural features revealing tree quality. Descriptive statistics for all variables, RMANOVA for DBH and height and for continuous variables mean+-+ standard deviation for categorical frequency and relative frequency variables were carried out. The results show a statistically significant positive long-term effect of thinning on tree growth, stem and crown features and support findings that thinning, by increasing growth and quality, is a necessary intervention in European beech and sessile oak low coppices. The recent economic crisis, the sudden increase in energy prices, and the increased demand for assorted wood products have initiated higher interest in coppices in Croatia.