Publications by authors named "R Benesperi"
In this study, we focused on the bedrock-dependent effects of climate change on terricolous lichen communities along elevational gradients in the Alps. In particular, we contrasted between carbonatic and siliceous bedrock, hypothesizing more favourable conditions on siliceous than on carbonatic bedrock, where dryer conditions may exacerbate the effects of climate change. To test this hypothesis, we compared terricolous lichen diversity patterns between the two bedrock types in terms of (1) species richness, (2) beta-diversity, (3) proportion of cryophilous species, and (4) functional diversity, also testing the effect of the elevational gradient as a proxy for expected climate warming.
View Article and Find Full Text PDFThe cortical anthraquinone yellow-orange pigment parietin is a secondary lichen substance providing UV-shielding properties that is produced by several lichen species. In our work, the secondary metabolite has been extracted from air-dried thalli of Xanthoria parietina. The aims of this study were to characterize parietin absorbance through UV-VIS spectrophotometry and with IR spectroscopy and to evaluate its photodegradability under UV radiation through in situ reflectance IR spectroscopy to understand to what extent the substance may have a photoprotective role.
View Article and Find Full Text PDFXanthoria parietina survivability in Mars-like conditions was supported by water-lysis efficiency recovery and antioxidant content balancing with ROS production after 30 days of exposure. Xanthoria parietina (L.) Th.
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- This study investigated how three types of biomonitors—Pinus nigra bark, Pseudovernia furfuracea lichen, and Hypnum cupressiforme moss—sorb mercury (Hg) in controlled indoor conditions of a historically Hg-polluted herbarium.
- The biomonitors were exposed for either 2 or 12 months and were monitored every 3 weeks for Hg content, gaseous elemental mercury (GEM) levels, temperature, humidity, and particulate matter.
- Results showed that barks were most sensitive to gaseous Hg pollution, while lichen and moss also reacted to varying climatic conditions, with all biomonitors displaying higher mercury accumulation in the initial weeks of exposure.
Article Synopsis
- Xanthoria parietina is a lichen that can tolerate high levels of UV radiation due to a compound called parietin, and researchers tested its survivability under simulated Martian conditions for 30 days.
- The study monitored the lichen's health using chlorophyll a fluorescence and found significant impacts on its photosynthetic efficiency, particularly between UV-exposed samples and those kept in darkness.
- Analyses through Raman spectroscopy and transmission electron microscopy showed that UV exposure led to decreased carotenoid levels and structural damage in the lichen's cells, but overall, X. parietina demonstrated resilience suitable for potential long-term space exposure.