Similarly to other Mediterranean regions, Italy is expected to experience dramatic climatic changes in the coming decades. Do to their poikilohydric nature, lichens are among the most sensitive organisms to climate change and species requiring temperate-humid conditions may rapidly decline in Italy, such in the case of the epiphytic Lobaria species that are confined to humid forests. Our study, based on ecological niche modelling of occurrence data of three Lobaria species, revealed that in the next decades climate change will impact their distribution range across Italy, predicting a steep gradient of increasing range loss across time slices. Lobaria species are therefore facing a high extinction risk associated with reduction of their range. The current patterns indicate that only L. pulmonaria still has a continuous distribution across Italy, with potential contact between Apennine and Alpine populations. This situation is consistent with the wider climatic niche of this species, still offering a major opportunity for its successful long-term conservation. Results (a) support the inclusion of the three Lobaria species in European conservation policies, such as the Habitat Directive, and (b) warn against an over-estimation of the indicator power of single flagship species to establish conservation priorities for lichens, indicating that even lichens with peculiar and similar climatic envelopes may fail to co-occur within a given forest stand. A multiple indicator approach could provide more useful tools for a community-based conservation strategy for epiphytes.

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Summary1. We attempted to elucidate the roles of b-diversity components and similarity in shaping Lobaria pulmonaria lichen communities in Italian forests to provide scientific tools for improving their longterm conservation. 2. A total of 20 sites were selected by stratified random sampling, including five chestnut forests, seven beech-silver fir forests and eight oak forests distributed across 10 administrative regions of Italy. Site selection was based on a national data base including all the available records of L. pulmonaria in Italy. In each forest, four plots were randomly placed, and in each plot, 5-6 trees were randomly selected for lichen sampling. For each forest and plot, meaningful predictors of lichen patterns were quantified. In particular, factors indicative of both geographic conditions and forests structure were considered. The SDR simplex approach was used to estimate the relative importance of similarity (S), relative species replacement (R) and relative richness difference (D) to b-diversity and similarity, while a hierarchical partitioning (HP) method was used to evaluate the relative importance of environmental predictors in explaining their patterns. 3. A total of 201 lichens and three nonlichenized fungi were found, including 51 species of conservation concern. The components of b-diversity and similarity contributed to shaping L. pulmonaria communities at both forest and plot scales across Italy, resulting in nearly random compositions, that is, the species set on each tree was a random sample from the available species pool. Species replacement and similarity were generally associated with forest structure predictors, while richness difference was mainly associated with geographic predictors. The implication of this is that the long-term conservation of L. pulmonaria communities could be promoted by maintaining scattered nodes and appropriate habitat traits, especially in large forested landscapes where species turnover is higher. 4. Synthesis. In this work, we used a new approach for analysing a countrywide data set improving the ecological understanding of the dynamics regulating epiphytic communities. In particular, this study improves the understanding of the contribution of different components of diversity across two spatial scales and evaluates the relative importance of environmental predictors in explaining variation of each diversity component.

Control of lichens on stone cultural heritage is mostly achieved by a combination of mechanical removal with biocide applications. However, there is a lack of scientific evidence on the efficacy of different biocides on different species, and on the consistency of biocide effects on heritage sites in different environmental conditions. This results in some uncertainty when conservation interventions to control lichens are routinely defined on the basis of restoration tradition or empirical evaluation, without experimental measures of how lichens respond. In this work, we quantitatively evaluated (a) the efficacy of five commercially-available biocides, applied using a brush or with a cellulose poultice, against two species (Protoparmeliopsis muralis, Verrucaria nigrescens), and (b) whether the effects on the two species were consistent, per treatment, across three Italian heritage sites. Lichen vitality was quantified through analyses of chlorophyll a fluorescence (ChlaF) and ergosterol content. The results indicated that all the tested biocides, and their organic solvents, affected the vitality of both the species. However, most of treatments displayed different efficacy on each species, across the different sites and between brush and poultice applications. Accordingly, when a conservation intervention to control lichen growth is planned, biocide treatments need both species- and site-specific calibrations and lichen vitality should be properly ascertained in situ by monitoring ChlaF parameters (FV/FM and F0) twenty days after trial biocide applications

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Link to this article: http://journals.cambridge.org/abstract_S0024282909008366How to cite this article: Claudia GAZZANO, Sergio E. FAVEROLONGO, Enrica MATTEUCCI and Rosanna PIERVITTORI (2009). Image analysis for measuring lichen colonization on and within stonework. The Lichenologist, 41, pp 299313Abstract: The suitability of image analysis by colour-based pixel classification to quantify lichen colonization on the surface of and within marble, travertine and mortar stonework has been investigated. High resolution images of lichenized stonework surfaces were acquired at different field sites using a scanner, thus avoiding invasive surveys, and the percentage cover of lichen species was subsequently measured in the laboratory using dedicated software. Furthermore, microphotographs of polished cross-sections of lichenized marble, travertine and mortar, stained using the periodic acid-Schiff (PAS) method to visualize hyphae, were produced by the same software to quantify hyphal spread within the substratum, a parameter which can be used more successfully than the commonly used depth of hyphal penetration to quantify how much the lichen has affected the conservation of a stone substratum. Significant statistical differences in hue, saturation and intensity (HSI) of the lichen thalli and PAS-stained hyphae, with respect to the lithic substrata, allowed the software to discriminate and quantify the lichen species cover on, and hyphal spread within, the three investigated lithotypes. Since such a quantitative approach highlights the volume of influence of lichens on stonework, where bioweathering processes are likely to develop, it could be used to support decisions on the preservation of our stone cultural heritage.