Subfossil oak wood has spent centuries or millennia in the aquatic medium (rivers, lakes, bogs, etc.) and, due to water anoxic conditions, its decomposition is very slow. As a result of its long residing in specific conditions, its chemical composition, appearance, as well as mechanical and tribological properties have changed. Because of its aesthetic and mechanical properties, subfossil wood is very attractive and often used to produce valuable objects. The main objective of this study was to test how abrasion wear resistance of subfossil oak is affected by ageing. The effects of ageing on wood density and on the structure of lignin and cellulose were tested, as well as the loss of volume during abrasion in correlation with these changes. A study was conducted on samples of recent (regular) pedunculate oak wood and on six subfossil pedunculate oak samples in the age range of 890 and nearly 6000 years. Abrasion wear resistance was expressed through the loss of volume recorded using the Taber abraser. The smallest abrasion volume loss was measured for the recent oak specimens. Linear regression analyses showed that there was a very strong negative linear relationship between the age of subfossil oak and its abrasion volume loss. There was also a strong, but positive and significant linear correlation between subfossil oak age and density. Ageing also affected the structural composition of wood. Results obtained by Fourier Transform Infrared spectroscopy indicated a reduction of the relative crystalline fraction of subfossil wood in recent oak. The degradation of lignin in subfossil oak samples progressed more slowly over time than cellulose degradation. There was a negative correlation between age and the ratio of cellulose and lignin degradation; however, that relationship was found statistically insignificant. Similar results were obtained for the relationship between abrasion wear resistance and changes in the structural composition of the studied samples of subfossil oak wood.

The Iron Age site of Kaptol-Gradci belongs to the south-eastern periphery of the Hallstatt cultural complex, dominated primarily by the Kaptol cultural group, and encompasses a hillfort settlement and necropolis. During the investigation campaigns organized to date, 25 tumuli have been identified and 17 of them investigated. This paper presents the first results of the analysis of plant remains from a Hallstatt necropolis in Croatia, from tumuli 6 and 7, identified as an integral part of the complex burial ritual. In both tumuli, the predominant finds were of cereal grains (83% in tumulus 6 and 96.9% in tumulus 7). Besides the cereal grains, a very small quantity of weeds representing accidental associations have also been identified, as well as remains of wild fruits collected in the countryside. On the basis of the first results obtained from the archaeological site of Kaptol-Gradci and the scarce archaeobotanical research into Hallstatt necropolises in Europe, the conclusion can be drawn that a potential pattern can be observed, an element of a complex burial ritual in which cereal grains (overwhelmingly dominant in terms of their relative proportions) played an important role, together with various fruit deposits, whose type and quantity probably depended on the season, their availability in the environment and/or the possibility of their storage/preservation.

Subfossil wood is a valuable and rare material often used for production of expensive furniture and decorative artistic items of unique beauty. Its mechanical and tribological properties are still being studied and are considered specific due to the particular conditions of its long-lasting formation in aqueous sediment sludge. Various elements that have been impregnated into the wood tissue over many years make the machining and grinding of this type of wood rather difficult compared to normal recent wood. The main objective of this study was to determine the influence of the abrasive grain size of sandpaper on the abrasion volume loss of recent and two subfossil oak samples in three characteristic sections (cross, radial, and tangential). The results showed that the average size of abrasive grains and the orientation of the wood structure have an influence on the abrasion volume loss of all three samples. The phenomenon of the critical size of abrasive grains was observed in all samples and on all sections. As the size of abrasive grains increased to the critical size, the abrasive volume loss of the sample increased simultaneously. The lowest abrasion volume loss was observed on recent oak. In all samples, the lowest volume loss was measured on the cross sections, and the tangential and radial sections had mutually equal values. It was also found that the increase in the size of abrasive grains to a critical value resulted in the increasing value of the absolute difference between the abrasion volume loss of the cross, radial, and tangential section samples, while the relative relations between the abrasive volume loss values of three different sections (C/R, C/T, R/T) within the same grit of sandpaper remained quite similar.

Arheološkim istraživanjima na lokalitetu Osijek – Ciglana i Zeleno polje utvrđeni su ostaci naselja iz brončanoga i željeznoga doba. Najstarije naselje, osnovano tijekom srednjega brončanog doba, kontinuirano je živjelo do starije faze kasnoga brončanog doba. Nakon dužega hijatusa, položaj je ponovno naseljen u mlađoj fazi starijega željeznog doba te zatim ponovno u kasnolatenskome razdoblju. Istraženost veće površine omogućila je praćenje promjena u strukturi i organizaciji naselja, dok provedene arheozoološke i arheobotaničke analize svjedoče o privredi stanovništva naseljenoga na istome prostoru tijekom dužega vremenskog razdoblja. Na brončanodobnom naselju najveće su promjene primjetne na prijelazu starije u mlađu srednjobrončanodobnu fazu, što se poklapa s nestankom inkrustirane keramike srednjega brončanog doba te nešto češćom pojavom materijala kakav se pripisuje kulturi grobnih humaka. Rezultati arheozooloških i arheobotaničkih analiza pokazuju kako se, bez obzira na promjene arheoloških kultura i razdoblja, privreda stanovništva naseljenoga na istome mjestu nije bitno mijenjala.

Tuškanac Forest Park has been floristically studied over the past 15 years, but most extensively and systematically during the year 2021. Tuškanac Forest Park is a natural treasure in the center of Zagreb City. This oblong 150-year-old stand of oak, common beech, and hornbeam is a natural extension of the vegetation of Mount Medvednica and descends almost to Zagreb's main street (Ilica). A total of 173 vascular plant taxa were recorded (62 families and 131 genera). The largest part of the flora consists of Angiospermae (163 taxa; 94.2 %), followed by Monilophyta (6 taxa; 3.5%) and Gymnospermae (4 taxa; 2.3%). Rosaceae is the richest family with 14 taxa (8.1%), followed by Asteraceae sensu lato (13 taxa; 7.5%), Poaceae (11 taxa; 6.4%), Lamiaceae (9 taxa; 5.2%) and Fabaceae (8 taxa; 4.6%). The highest percentage of recorded plants are hemicryptophytes (41.0%) and phanerophytes (27.7%). The analysis of chorotypes shows that the Eurasian floral elements dominate (50.9%), followed by European (18.5%) and Mediterranean elements (8.1%). Urbanophobic (45.3%) significantly outnumber urbanophilic taxa (8.7%). A “close to nature“ environmental condition is additionally confirmed by the low values calculated for indicators of anthropogenisation and by the low share of alien flora (27 taxa; 15.6%). The following invasive alien taxa grow in the study site: Ailanthus altissima, Duchesnea indica, Erigeron annuus, Parthenocissus quinquefolia, Phytolacca americana, Robinia pseudoacacia and Veronica persica. According to IUCN categories, only two taxa belong to threatened categories: Taxus baccata and Lilium martagon are vulnerable (VU) and both taxa are strictly protected in Croatia.