Lichen-induced biodeterioration of Italian monuments, frescoes and other archaeological materials

An appraisal is made of the part played by lichens in the deterioration of stonework. Stone- and artwork in exposed and partially enclosed environments of Central Italy were examined in detail to identify those substrata most vulnerable to lichen attack. Assessment of relationships between particular species and the physical and chemical nature of their substrata was carried out in order to determine the relative importance of lichens in biodeterioration processes obtaining in specific circumstances, and to establish those species responsible for disfigurement and those causing actual destruction. Particular attention is paid to recent environmental changes conducive to increasing detrimental invasion of terracotta, mortar and painted plaster, and reference is made to examples of building materials, statuary and other ornamental carvings, terracotta pots and frescoes, both those in situ at Ostia Antica, Rome and Caprarola (Viterbo) and those relocated in open-air museums, etc

The use of autoecological and environmental parameters for establishing the status of Lichen vegetation in a baseline study for a long-term monitoring survey

International audienceIn 1997 the ecological characteristics of the epiphytic species (83 lichens and two algae) of an urban area (Grenoble, France) were determined. Seven autecological indices were used to characterize the lichen ecology: illumination index, humidity index, pH of bark, nutrient status of substratum, ecological index of IAP and frequency. Six clusters (A1–A6) were defined using cluster analysis and principal component analysis. Seven environmental parameters characterizing the stations and the lichen relevés were also used: elevation, parameters of artificiality (urbanization, traffic and local land use), IAP, and the percentage of nitrophytic and acidophytic species. Six clusters (B1–B6) were defined using cluster analysis and canonical correspondence analysis. Four clusters (C1–C4) were finally defined using an empirical integrated method combining the autecological and environmental parameters. This final clustering which established the status of the lichen vegetation in 1997 can be reliably used as a baseline study to effectively monitor environmental changes in this urban area. Ecological clustering which establishes the status of lichen vegetation can be reliably used as a baseline study to monitor environmental changes

Lichens and tobacco plants are complementary biomonitors of air pollution in the Grenobla area (Isère, southeast France)

International audienceThis biomonitoring study was aimed at providing an overall assessment of nitrogen oxides (NOX) and tropospheric ozone (O3) in the Grenoble area (Isère, France). Two bioindicators, lichens and tobacco plants, were used to estimate, respectively, the spatial distribution of NOX and O3. The following methodological approaches were adopted: bioaccumulation of nitrogen in the lichen Physcia adscendens, bioindication of ozone as shown by visible injury to tobacco plants (cv. Bel W3), and biomonitoring at the lichen community level (IAP). Complementary biomonitoring maps, the first based on nitrogen concentrations of lichens and the second based on tobacco leaf injuries, were highly comparable with results obtained from physico-chemical analyses. Multivariate analyses (Canonical Correspondance Analysis) were used to determine the relationships between levels of atmospheric NO2 and O3 and the lichen communities (IAP). A lichen sensitivity scale to NO2 and O3 was attempted for 43 epiphytic species, from which it was possible to define five clusters according to their indifference, sensitivity or resistance to NO2 and O3