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Due to the specific microclimatic conditions, mural paintings placed in hypogean monuments occur to biological attack. The application of natural biocides, safe and eco-friendly, is the bet- ter solution to prevent biodeterioration phenomena in this context. Lately, many new green biocides have been developed but applied in the conservative intervention only to a minor ex- tent; because of the fewer data about the interaction of the new products with the substrate. This study aimed to investigate the interference test of four green biocides on mural painting in Etruscan tombs (Necropolis of Monterozzi, Tarquinia). Mock-ups of Etruscan mural painting were reproduced and tested in similar hypogean microclimatic conditions. Colorimeter, contact sponge method and portable optical microscope were applied.

Cultivated terraces are outstanding modifications of mountains and hills to obtain arable land. These terraced agricultural systems are widespread traditional landscapes within the Mediterranean area. The cultivated terraces of the Amalfi Coast (Southern Italy) are outstanding examples of cultural landscapes, and they represent one of the key descriptors of the UNESCO Site. Terraces have characterized the landscape of the Amalfi Coast for a long time as their construction started during the Middle Age. However, their conservation is now threatened by abandonment, which has dramatically risen in the last 60 years, and by the ongoing climatic changes with the increased incidence of heavy rainfall events. We combined interviews with local farmers and vegetation surveys to understand which management activities are carried out to improve the conservation of cultivated terraces on the Amalfi Coast. To this end, we analyzed the linkages between these management practices and their influence on the vegetation growing on the terrace risers. Our informants identified the maintenance of waterways and walls as crucial factors influencing terrace and slope stability. The preservation of the integrity of terraces depends on periodic vegetation control and the maintenance of water drainage systems, which are carried out thanks to the active presence of farmers. According to our informants, the vegetation growing on the walls has a relevant role in the stability of terraces, and we found a prevalence of Hemicryptophytes that increase with the number of interventions over the year. Thus, active and vital agriculture becomes pivotal for the preservation of this cultural heritage.

Coupled human–environment systems and traditional agricultural landscapes can be a key element in the conservation of biodiversity, ecological functionality, and cultural heritage. Terraced landscapes are a relevant example of traditional landscapes within the Mediterranean area, but they are now threatened due to the abandonment of agricultural activities. In order to identify factors that can affect the conservation strategies needed to maintain terraced landscapes in the Mediterranean area, we performed a literature review on studies about terraces and their management, soil erosion and vegetation dynamics after abandonment, etc. We collated a total of 285 scientific papers reporting 293 case studies in 19 countries. The majority of these studies analyze dry stone terraces and their influence on soil erosion and water runoff, either in cultivated or abandoned terrace systems. Only a minority of papers suggest maintenance or conservation strategies or involve farmers, exploring their decision-making. The conservation of terraced landscapes is in the hands of local farmers, and thus they should be actively involved in decision-making to find the most suitable strategies for assuring the continuity in farming and preserve cultural landscapes in the Mediterranean area.

The hypogeal cultural heritage due to their favourable environmental conditions can be subject to microbial attack usually controlled using biocides. Recently the number of products allowed in the restoration practice has been reduced because, in addition to their effectiveness, the biocidal product should not have effects on the treated surfaces, and it should be safe for the operator and environment. Following this field research, we propose a reconstruction experiment in which we tested 4 different natural products (Clove oil, Oregano Oil, Usnic Acid, IPA+ DMSO + Usnic Acid) on tiles, reproducing the substrate of Etruscan hypogeal tombs (Macco) of Monterozzi Necropolis, inoculated with a selection of fungal/bacterial strains. After one month from the biocide’s application, we evaluated their efficiency by image analysis and by culture analysis. The achieved results evidenced a clear gradient between the four tested biocides and gave suggestions for further improvements.

In the last decade, worldwide research has focused on innovative natural biocides and the development of organic and inorganic nanomaterials for long-lasting reliability. In this work, the biocide effects of two different biocides encapsulated in two different silica nanosystems for a multifunctional coating have been performed through in vitro tests, by using Chlorococcum sp. as a common stone biodeteriogen. Zosteric sodium salt (ZS), a green biocide, was compared with the commercial biocide, 2-mercaptobenzothiazole (MBT), widely used in the treatment of cultural heritage. The analyzed systems are the following: silica nanocapsules (NC) and silica nanoparticles (MNP) not loaded with biocides, two nanosystems loaded with ZS and MBT, and free biocides. The qualitative and quantitative evaluations of biocide efficiency were performed periodically, analyzing pigment autofluorescence to discriminate between active and inactive/dead cells. The analyses showed multiple differences. All the nanocontainers presented an initial reduction in chlorophyll’s autofluorescence. For the free biocide, the results highlighted higher efficiency for MBT than ZS. Finally, the nanosystems loaded with the different biocides highlighted a higher activity for nanocontainers loaded with the commercial biocide than the green product, and better efficiency for MNP in comparison with NC.

The use of traditional biocides to reduce bio-deterioration phenomena of stone monuments is increasingly deterred, due to risks for human health and the environment, as well as for potential interference with materials. Extensive research is now ongoing, aiming to find alternative and eco-friendly substances or methods to halt or reduce bio-deterioration. Here we aim to provide an assessment of the results of scientific tests, in order to evaluate the most promising substances, likewise possible deficiencies and future directions in research. We performed an extensive literature review on natural biocides for controlling bio-deterioration of stone using peer-reviewed articles between 1986 and 2018. The dataset created displays information about the experimentation of a total of 61 natural substances, mostly essential oils (23), or substances of plant origin and other compounds. The methods of application of such biocides were diverse, but the in vitro tests were the prevailing ones. The most tested organisms were fungi, followed by cyanobacteria and algae. The efficacy of the substances resulted highly variable, as did protocols and experimental doses, resulting in a lack of a robust and coherent assessment of best practices. Also, we found a few papers discussing the interference of these substances with the substrate. We believe that this area of research is very promising and necessary, although additional tests with a standardised methodology are still needed.

Vegetation management of archaeological sites is a recurrent problem when considering the conservation of historic structures and biodiversity. In the UNESCO site of the Etruscan necropolis “La Banditaccia” (Cerveteri, Italy), several plants grow on the ancient tumuli, which are subjected to different management practices. In order to assess the influence of interventions on plant colonisation, a comparative analysis of several tumuli was performed, through structural, chorological, phytosociological and statistical evaluations. This investigation identified and defined an ecological gradient among the tumuli. The cover values of Therophytes and Hemicryptophytes decreased by half with regular cutting, while those of Geophytes and Phanerophytes increased. Mesophilic field plants (MFP), both ephemeral and perennial, represented the most abundant group. Mediterranean bushes and forests (MBF) showed a positive trend from the entrance to the last tumuli of the necropolis. This trend was clearly defined by PCA, and it seems community changes were caused by the absence of mowing activities and to a lower tourist frequentation. SIMPER analysis highlighted which species on each tumulus mainly influence their dissimilarity. This knowledge, when combined with the evaluation of the potential risk of the different plant communities growing on the tumuli, can help to identify the best management practices.

Archaeological sites can represent a refuge for plant and animal species, protecting them from the pressures of urbanisation. However, sometimes these environmental resources can lead to negative consequences for the monuments. In order to investigate such contrasting effects, we selected the UNESCO World Heritage Site Etruscan necropolis known as “La Banditaccia” (Cerveteri, Italy). We performed floristic and phytosociological analyses, and observations on roots interactions with monuments on several tombs (9 tumuli and 5 cube-shaped tombs) and applied commonly used indices to evaluate damages to the structures. The study revealed rich biodiversity of the site and the presence of rare plants, but also of some invasive species. The analysis of the phytosociological sets showed differences among vegetation types found on the tumuli as a function of the varying degrees of anthropization. Abundant plant colonisation was detected on the top of the tumuli, sometimes causing damages to the structures. The results of the Impact Index analysis showed that the dynamic evolution of vegetation constitutes a significant risk to the archaeological structures. We suggest that careful management of vegetation should achieve equilibrium between the management requirements for the monuments and conservation of naturalistic values. A deeper evaluation of the interactions between plants and monuments is however necessary.

Different quantitative indices were proposed to determine the cultural importance of ethnobotanically valuable plants in order to develop a tool for the evaluation of immaterial cultural heritage. These indices were applied to an ethnobotanical survey of food and nutraceutical plants traditionally consumed in Bali, Indonesia. The uses of the plants were grouped into 6 use categories. The Cultural Food Significance Index (CFSI), use value (UV), relative frequency of citation (RFC), relative importance (RI), cultural value (CVs), and informant consensus factor (ICF) were calculated for a list of plants cited by fifty informants in different traditional villages on the island. This evaluation of the cultural importance of plants through different indices produced interesting variations. Colocasia esculenta (L.) Schott came highest in the preference ranking for RFC, UV and CVs. Arenga pinnata (Wurmb) Merr. was in first place for CFSI and RI. Artocarpus heterophyllus Lam., Lablab purpureus (L.) Sweet and Cinnamomum burmanni (Nees & T. Ness) Blume were also high in the CFSI, RI, and CVs. The ICF results revealed a well-defined food tradition. The combined use of these indices, as opposed to any single index, makes it possible to quantify the role that a given plant plays within a particular culture.

Summary The inventory of microorganisms responsible for bio- logical deterioration of ancient paintings has become an integral part of restoration activities. Here, the microbial agent of rosy discoloration on medieval fres- coes in the Crypt of the Original Sin (Matera, Italy) was investigated by a combination of microscopic, molecular and spectroscopic approaches. The bacte- rial community from three rosy-discoloured painting sites was characterized by 16S rRNA gene-based tech- niques. The eubacterial population was prevalently composed of Actinobacteria, among which Rubro- bacter radiotolerans-related bacteria accounted for 63-87% of the 16S rRNA gene pool per sampled site. Archaea, with prevalence of Haloarchaea-related species, were detected in one of the three sites where they accounted for < 0.1% of the total 16S rRNA gene pool. Raman spectroscopy confirmed the identity between R. radiotolerans carotenoids (bacterioru- berins) and pigments responsible for colour alteration of frescoes. This investigation provides the first evidence of a causal relationship between heavy con- tamination by Rubrobacter-related bacterioruberin- producing bacteria and rosy discoloration of ancient wall paintings.