Dendrochronological analysis was carried out at the archaeological settlement of Gran Carro, located in Lake Bolsena (Italy). According to the most recent archaeological evidence, the site dates back to the period spanning from the Middle Bronze Age (15th century BC) to the Early Iron Age (8th century BC). In the excavation of the archaeological area, wooden piles from deciduous oak species (Quercus section robur and Quercus section cerris) were found, species still common in the area. The analysed trees, aged 15–50 years, likely came from managed forests, though agamic regeneration is possible. Relative felling dates provide initial insights into the duration of the settlement phases, revealing modifications to the original structure over an interval year ranging from 9 to 23 years. Absolute dating using wiggle matching indicates that most of the analysed piles date between 934 and 810 BC, though calibration curve slope limits precision. Nonetheless, dendrochronological analysis suggests that the settlement associated with an individual dendrogroup can likely be placed more precisely within this time range from 907 to 885 BC. From a broader perspective, the excavated area so far indicates that the settlement can be dated with 95% probability to the period 1054–810 BC and with 68% probability to the period 1017–817 BC. The results represent a significant milestone and may offer valuable insights for future investigations and developments.

Waterlogged archaeological wood (WAW) is a rare and precious organic material that can hold outstanding cultural values. In order to protect WAW for the next generations, this material must be accurately characterized to set its proper conservation, storage and exhibition conditions in museum environments. In this study, the mineral content found in WAW retrieved in a volcanic lake, was investigated by analysing wood ash through scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS). This micro-destructive approach was coupled with morphological studies carried out through optical microscopy. SEM-EDS was also performed on the WAW and on the surrounding sediment, to study the possible correlation between the mineral composition and the wood degradation state. The analysis revealed that calcium was the most abundant element in all poles with weight percentages ranging between 24 % and 42 %. This element was more represented in heartwood (HW) than sapwood (SW). In Sapwood the second most abundant element was arsenic. Sulphur, iron, and potassium were also present in all the analysed samples. Arsenic was detected also in the sediments; it was particularly concentrated in the samples taken near archaeological wood. The presence of this element can be linked to the volcanic origin of the lake, and its high concentration points to bioaccumulation processes induced by bacteria (erosion bacteria and sulphate-reducing bacteria) and biochemical processes favouring precipitation of insoluble compounds. The present work is the first investigation on mineral content in archaeological wood establishing a possible correlation with the surrounding volcanic lake sediments.

Wooden pile dwellings (WPD) are an inexhaustible and precious source of information on landscape evolution and contingent cultural activities. There have been significant investigations on WPD submerged in Alpine areas, but important knowledge gaps are evident regarding Mediterranean volcanic and karstic lakes. The conservation of the latter archaeological remnants is endangered by the climatic change impacts and anthropogenic pressure, further exacerbated by the sensitive and circumscribed lake environments. Wood from pile dwellings is waterlogged, and its conservation mostly depends on the surrounding environment i.e. sediments and water quality. This project aims to study all the aspects of WPD in volcanic and karstic lakes through studies ranging from their potential exploitation, the investigation into their conservation and restoration, monitoring lake environment and forecasting scenarios through an aquarium reproducing the most significant abiotic conditions occurring in the lake. This last study will be achieved by means of an aquarium model. Three case studies have been selected in which agricultural practices influence climatic stress and pollution impact: Lake Banyoles in Spain and Lakes Bolsena and Mezzano in Italy. The foreseen investigations will employ an extraordinarily wide spectrum of skills and disciplines (palynology, dendrochronology, micromorphology, soil science and innovative tools like isotopic analysis). The characterization of wooden materials will involve gravimetric measurements, Fourier-transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetry. Samples will derive from different sources to include immersed, reburied finds and restored wood, lake water and lake sediment samples. The main activities will be devoted to fields campaigns and unmanned aerial vehicle (UAV), high-resolution methods for monitoring environmental conditions (for example the installed probe will measure water lake temperature, pH and so on), capitalization of results (network of big data about lake sites), involvement of local actors and population on the historical, cultural and environmental value of WPDs to establish decision-making processes and to foster high-quality tourism.

This study examines the impact of recent climatic trends on the preservation of submerged wooden structures at the Gran Carro archaeological site in Lake Bolsena, Italy. Climatic data from the Bolsena Meteorological Station were analysed alongside in situ water quality measurements collected near the archaeological remains at a depth of 4 m. The key parameters included water temperature (Tw), redox potential (Eh), dissolved oxygen (DO), and total dissolved solids (TDS). Trend analyses using the Mann–Kendall test and Sen’s slope revealed significant increases in air and water temperatures, which were strongly correlated. Although precipitation exhibited an upward trend, its negative correlation with temperature suggests greater variability rather than a stable water supply. Despite increased rainfall, lake levels showed a significant decline, likely due to intensified evaporation and water extraction for irrigation. UAV surveys confirmed recent lowering of the lake’s water surface during drought periods. Among the limnological parameters, dissolved oxygen saturation declined significantly, while redox potential increased, indicating shifts toward more anaerobic conditions. These environmental changes could promote the activity of erosive bacteria that degrade submerged wood. Conversely, increased evaporation might also enhance oxygen penetration at depth, potentially activating decay agents such as soft rot fungi and wood-boring bacteria. Overall, the findings suggest that ongoing climatic changes are adversely affecting the preservation of submerged wooden structures, highlighting the need for adaptive management strategies to protect both the lake ecosystem and its archaeological heritage.

Conservation and restoration interventions must be implemented whenever the preservation of a cultural asset and its transmission to future generations, is deemed at risk. The causes and mechanisms by which cultural heritage undergoes progressive deterioration are numerous and complex, as are the restoration operations devised to address various issues and ensure their preservation. In light of the recent and growing need to identify solutions that are not only effective but also environmentally sustainable, promoting a gradual ecological transition in the field of cultural heritage, there is increasing interest in green materials and methods. Within this context, the ICR, is currently exploring the possibilities of bio-based solutions for consolidation purposes. The joint efforts of restoration and scientific laboratories is especially devoted to experimental campaigns started in order to test innovative environmentally friendly nanomaterials. As a part of these activities, ICR is recently focussing on the investigation of nanocellulose compounds for the consolidation and structural reinforcement of organic supports of cultural heritage, such as textile fibres, canvas, wood and paper. Nanocellulose, capable of obtaining good results without altering their main characteristics and chemical properties of cellulosic substrates, represents an attractive alternative to the use of synthetic polymers.

This study examines the impact of recent climatic trends on the preservation of submerged wooden structures at the Gran Carro archaeological site in Lake Bolsena, Italy. Climatic data from the Bolsena Meteorological Station were analysed alongside in situ water quality measurements collected at a depth of 4 meters near the archaeological remains. Key parameters included water temperature (Tw), redox potential (Eh), dissolved oxygen (DO), and total dissolved solids (TDS). Over the past decade, there has been an increase in days with air temperatures exceeding 30 °C and a general rise in mean temperatures. In 2022 and 2023, elevated air temperatures correlated with increased water temperatures, decreased redox potential, and reduced dissolved oxygen levels. Additionally, high evapotranspiration rates and declining water levels, as confirmed by UAV analyses, suggest intensified stress on the lake ecosystem, particularly due to increased water extraction for irrigation. These conditions may have created an environment with heightened anaerobicity, favouring the activity of erosion bacteria known to degrade submerged wood. Conversely, higher evapotranspiration rates could facilitate oxygen penetration to lower depths, potentially reactivating decay agents such as soft rot fungi and tunnelling bacteria. Overall, these climatic changes appear to have a detrimental effect on the preservation of submerged wooden structures in the lake. Consequently, adaptive management strategies will be necessary to mitigate these impacts and ensure the protection of both the lake environment and the archaeological wooden remains.