European beech (Fagus sylvatica L.) forests provide multiple essential ecosystem goods and services. The projected climatic conditions for the current century will significantly affect the vitality of European beech. The expected impact of climate change on forest ecosystems will be potentially stronger in southeast Europe than on the rest of the continent. Therefore, our aim was to use the long-term monitoring data of crown vitality indicators in Croatia to identify long-term trends, and to investigate the influence of current and previous year climate conditions and available site factors using defoliation (DEF) and defoliation change (ΔDEF) as response variables. The results reveal an increasing trend of DEF during the study period from 1996 to 2017. In contrast, no significant trend in annual ΔDEF was observed. The applied linear mixed effects models indicate a very strong influence of previous year drought on ΔDEF, while climate conditions have a weak or insignificant effect on DEF. The results suggest that site factors explain 25 to 30% DEF variance, while similar values of conditional and marginal R2 show a uniform influence of drought on ΔDEF. These results suggest that DEF represents the accumulated impact of location-specific stressful environmental conditions on tree vitality, while ΔDEF reflects intense stress and represents the current or recent status of tree vitality that could be more appropriate for analysing the effect of climate conditions on forest trees.
Although game meat quality has been under the spotlight in numerous studies, the quality of brown bear (Ursus arctos) meat is still unknown. The aim of this study was to determine the effects of sex and age on the proximate chemical composition, fatty acid profile, and lipid indices of brown bear meat. Nine (n = 9) females and nine (n = 9) males were hunted during the Croatian spring hunting period in 2018. Based on age, bears were divided into two groups: <3 years (n = 9; five females and four males) and 4–6 years (n = 9; four females and five males). For analysis purposes, samples of M.semimembranosus were collected. Age was shown to have an effect on the traits analyzed, while sex-related differences were not found. Brown bear meat has a high fat content (average 6.12%), especially in older bears (~9%). The contents of protein, dry matter, and ash were similar to those of other game species. Monounsaturated fatty acids made up approximately 50% of all fatty acids, with the most abundant being C18:1n-9. More favorable profiles of essential polyunsaturated fatty acids were found in younger bears. The ratio of polyunsaturated and saturated fatty acids was closer to the recommended ratio than the ratio of n-6 and n-3 polyunsaturated fatty acids, and lipid indices were favorable. Further research is needed to determine seasonal changes in brown bear meat quality.
The aim of this study is to examine the effect of sex and age on proximate chemical, fatty acid, amino acid and mineral content of axis deer (Axis axis Erx.) meat. Sixteen (n = 16) animals were hunt-harvested and assigned to groups according sex and age (sub-adult and adult). All analyses were made on m. longissimus thoracis sampled between the 9th and 13th ribs. Minor differences in nutritional composition of axis deer meat were found between analysed sex and age groups. Axis deer meat has a high protein (22.8%) and low fat (1.39%) content. Saturated fatty acids accounted for 44.97% and polyunsaturated for 29.66% of the total fatty acids. Ratios of fatty acids were within the recommended values. Glutamic and aspartic acid were the most abundant non-essential, and lysine and leucine the most common essential amino acids. The ratio of essential to non-essential amino acids was <1. Potassium and phosphorous were the dominant macro-minerals, while iron and zinc were the dominant micro-minerals. The results of this study show that regardless of sex or age, axis deer meat can be considered a good source of basic macro- and micro-nutrients, and can be recommended as a substitute for red meat from domestic animals.
The Mediterranean vegetation belt on the eastern Adriatic covers an area of nearly 15,000 km2. It is comprised of forest stands that can be divided into three vegetation zones based on the presence of certain plant species within each: sub-Mediterranean, eu-Mediterranean, and steno-Mediterranean. The dominant ecological factors result in the domination of specific tree species within the floral composition between these vegetation zones. The aim of this study was to collect climate data from 38 weather stations over a 30-year period to compare climate data and bioclimate properties in the area of these three vegetation zones. The results confirmed statistically significant differences between the main climatic elements and most bioclimatic indices between the vegetation zones. Cooler and more humid conditions were found in the sub-Mediterranean zone, warmer and somewhat drier conditions in the eu-Mediterranean zone, and particularly pronounced warm and dry conditions in the steno-Mediterranean zone. However, the analysis of the main components for researching climate parameters showed that the mean annual air temperature, average minimum air temperature of the coldest month of the year and continentality index, length of the dry season, and de Martonne aridity index contribute the most to the grouping of vegetation in forest stands in the Mediterranean vegetation belt of the eastern Adriatic.
European beech (Fagus sylvatica L.) is an important component of forests in the alpine and continental biogeographical regions of Croatia. This study aimed to (1) analyze the long-term response of beech to climate, (2) identify potentially critical climatic conditions that could negatively affect the radial increment (RI) and vitality of beech, and (3) evaluate differences in the response of beech between the two biogeographical regions in Croatia. We used the 16 × 16 km Croatian ICP Forests Level 1 network. On a total of 25 plots, we cored between 5 and 24 trees for dendrochronological analysis. Tree-ring widths (TRW) were measured and standardized using cubic spline. TRW chronologies for the two regions were calculated and correlated to the temperature and precipitation data and Standardized Precipitation and Evapotranspiration Index (SPEI) using bootstrapped correlations. Continental region precipitation from April to August and alpine region precipitation from June to August were significantly important for RI. Temperature was less important for RI than precipitation in both regions, but the importance of the negative impact of above-average temperatures in the continental region and the positive impact of above-average precipitation in the alpine region has increased over the last two decades. A comparison with the 3-month SPEI confirmed the significant influence of high temperatures and the lack of precipitation in August on the RI of beech trees in both regions.
Despite being adapted to a wide range of environmental conditions, the vitality of European beech is expected to be significantly affected by the projected effects of climate change, which we attempted to assess with foliar nutrition and crown defoliation, as two different, yet interlinked vitality indicators. Based on 28 beech plots of the ICP Forests Level I network, we set out to investigate the nutritional status of beech in Croatia, the relation of its defoliation and nutrient status, and the effects of environmental factors on this relation. The results indicate a generally satisfactory nutrition of common beech in Croatia. Links between defoliation and nutrition of beech are not very direct or very prominent; differences were observed only in some years and on limited number of plots. However, the applied multinomial logistic regression models show that environmental factors affect the relationship between defoliation and nutrition, as climate and altitude influence the occurrence of differences in foliar nutrition between defoliation categories.