Change in atmospheric deposition during last half century and its impact on lichen community structure in Eastern Himalaya

Unraveling the ameliorative potentials of native lichen Pyxine cocoes (Sw.) Nyl., during COVID 19 phase

Due to the rapid increase in the novel coronavirus virulence, the entire world implemented the practice of lockdown along with the constraint of human movement. The obligation of quarantine halted most of the commercial and industrial movement that prominently disturbed the distinct key environmental parameters directly associated with the plant's and animal's health conditions. In this regard, the research aims to study the sudden shut-off of vehicular activity impact on the naturally growing lichen of the genus Pyxine cocoes. The results showed an increase in the pigments, Fv/Fm ratio, and phytohormones during the lockdown and concurrently the decreasing levels in the post-lockdown period. Interestingly, modulations in the phytohormones occur in the lockdown period as compared to the post-lockdown period. The metals Al, Cr, and Fe show the highest increasing trends in the unlocking period, whereas As, Cd, Pb, Cu, Hg, Mn, and Zn show very little variation during the running and post-lockdown phases. The lichen photosynthetic activity justifies further examination as initial biological indicators of the abrupt environmental variations prompted by such types of atmospheric situations and, to a greater extent, for the risk assessment in the near future. In conclusion, stress-phytohormone and amino acids play a significant role as stress reducers. Although lichens are well known for long environmental assessment, the present study will provide qualitative and quantitative variation in physiochemical changes in the short term and sudden environmental fluctuations. HIGHLIGHTS: • Qualitative and quantitative variation in biochemical parameters in lichen during and post-lockdown period was analyzed. • Stress-phytohormone and amino acids play a significant role as stress reducers. • Selectivity sequence reflection in heavy metal accumulation may be used in future studies.

Predicting the distributional range shifts of Rhizocarpon geographicum (L.) DC. in Indian Himalayan Region under future climate scenarios

Himalaya, the highest mountain system in the world and house of important biodiversity hotspot, is sensitive to projected warming by climate change. Rhizocarpon geographicum (map lichen), a crustose lichen, grows in high mountain ranges, is a potential indicator species of climate change. In the present study, MaxEnt species distribution modeling algorithm was used to predict the suitable habitat for R. geographicum in current and future climate scenarios. Nineteen bioclimatic variables from WorldClim database, along with elevation, were used to predict the current distribution and three representative concentration pathway (RCP) scenarios by integrating three general circulation models (GCMs) for future distribution of species covering years 2050 and 2070. Furthermore, we performed change analysis to identify the precise difference between the current and future distribution of suitable areas of the species for delineating habitat range expansion (gain), habitat contraction (loss), and stable habitats. The final ensemble model obtained had average test value 0.968, and its predicted ~ 27.5% of the geographical area in the Indian Himalayan Region is presently climatically suitable for the species. The predicted highly suitable area for R. geographicum is observed to be declining in Northwestern Himalaya, and it is shifting towards the higher elevation areas of the Eastern Himalaya. The projected distribution in future under the RCP scenarios (RCP 4.5, 6.0, and 8.5) showed the range expansion towards higher elevations, and it is more pronounced for the extreme future scenarios (RCP 8.5) than for the moderate and intermediate climate scenarios (RCP 4.5 and RCP 6.0). However, assuming that species can migrate to previously unoccupied areas, the model forecasts a habitat loss of 10.86-16.51% for R. geographicum, which is expected due to increase in mean annual temperature by 1.5-3.7 °C. The predictive MaxEnt modeling approach for mapping lichen will contribute significantly to the understanding of the impact of climate change in Himalayan ecosystems with wide implications for drawing suitable conservation plans and to take adaptation and mitigation measures.

The Genus Cetraria s. str.-A Review of Its Botany, Phytochemistry, Traditional Uses and Pharmacology

The genus Cetraria s. str. (Parmeliaceae family, Cetrarioid clade) consists of 15 species of mostly erect brown or greenish yellow fruticose or subfoliose thallus. These Cetraria species have a cosmopolitan distribution, being primarily located in the Northern Hemisphere, in North America and in the Eurasia area. Phytochemical analysis has demonstrated the presence of dibenzofuran derivatives (usnic acid), depsidones (fumarprotocetraric and protocetraric acids) and fatty acids (lichesterinic and protolichesterinic acids). The species of Cetraria, and more particularly Cetraria islandica, has been widely employed in folk medicine for the treatment of digestive and respiratory diseases as decoctions, tinctures, aqueous extract, and infusions. Moreover, Cetraria islandica has had an important nutritional and cosmetic value. These traditional uses have been validated in in vitro and in vivo pharmacological studies. Additionally, new therapeutic activities are being investigated, such as antioxidant, immunomodulatory, cytotoxic, genotoxic and antigenotoxic. Among all Cetraria species, the most investigated by far has been Cetraria islandica, followed by Cetraria pinastri and Cetraria aculeata. The aim of the current review is to update all the knowledge about the genus Cetraria covering aspects that include taxonomy and phylogeny, morphology and distribution, ecological and environmental interest, phytochemistry, traditional uses and pharmacological properties.

The multi-isotope biogeochemistry (S, C, N and Pb) of Hypogymnia physodes lichens: air quality approach in the Świętokrzyski National Park, Poland

The isotope biogeochemistry of bioindicators has widely demonstrated its added value in environmental issues by allowing to precisely identify sources of contamination. Most of the studies are based on studying one or two isotope systematics. Here, we are presenting an innovative multi-proxy approach that combines chemistry with both stable (C, S, N) and radiogenic (Pb) isotope systematics. Using Hypogymnia physodes bioindicators, we evaluated air quality in the complex environment of the Świętokrzyski National Park (ŚNP, Poland) with the ultimate objective of isotopically identifying the sources responsible for the observed contamination. Combining the isotope systematics showed that home heating is a major source of contamination in winter, whereas the contribution of road traffic increases during the summer. Pb isotope ratios identified industrial activities as the major source of this metal in the atmosphere.

Air quality assessment in different environmental scenarios by the determination of typical heavy metals and Persistent Organic Pollutants in native lichen Xanthoria parietina

The study was aimed to evaluate the ability of native lichen Xanthoria (X.) parietina to biomonitor and bioaccumulate some heavy metals (As, Cd, Co, Cr, Ni, Pb), PAHs, PCDDs, PCDFs, PCBs and PBDEs and to evaluate the use of the native X. parietina as a multi-tracer tool for scenarios characterized by different anthropogenic pressures. Samples of native X. parietina were collected in six different sites (two green, two residential and two industrial areas, respectively) and analyzed for the target compounds. The results show that X. parietina was a useful tool for the biomonitoring of air quality in the selected areas, and was able to bioaccumulate all the studied metals and POPs. In particular, the total concentrations dry weight (dw) ranged between 8.1 and 103.4 mg kg^-1 for metals, from 113 × 10³ to 183 × 10³ ng kg^-1 for PAHs, from 868 to 7685 ng kg^-1 for PCBs, from 14.3 to 113.8 ng kg^-1 for PCDDs/Fs (∑TEq = 0.9-7.1), and from 194 to 554 ng kg^-1 for PBDEs. Besides, in general, the levels of analytes recovered in the different samples of lichen show an increasing trend from green to industrial sites, especially for PCBs (mean values equal to 1218, 4253 and 7192 ng kg^-1 respectively for green, residential and industrial areas). The statistical approach, based on Pearson's correlation and principal component analysis tests, showed that one of the industrial sites was well-separated from the others, that resulted grouped due to some similarities.

Long-term lichen trends in a rust belt region

Deindustrialization and national air pollution standards greatly reduced air pollution in the USA since the mid-20th century, particularly in the ‘rust belt’ industrial cities of the Great Lakes and Northeastern regions. Still, sprawling urbanization, vehicular traffic and coal-fired power plants may maintain regional heat islands and NOx and SO2 pollution. Lichens are one of the first, and longest used, bioindicators of urban heat island effects and atmospheric pollution, but there are few long-term studies of lichen bioindications. We examined herbaria records for lichens collected between 1869 and 2016 in the Western New York (WNY) region (USA). We hypothesized a long-term trend of increasing pollution-sensitive lichens in the region as well as increased desiccation-tolerant species from urban heat island effects. We also evaluated local (urban and tree land use cover) and regional (ecological zones) influences on pollution-sensitive and desiccation-tolerant lichens. We found that the WNY lichen communities appear to be shaped by urbanization with desiccation- and pollution-tolerant species dominating areas adjacent to the urbanized/industrialized core, and direct local effects of the urban heat island and vehicle traffic within the urban core. These results suggest that despite deindustrialization and tighter air quality standards, an industrial imprint remains on the lichen communities of WNY. However, despite urban filtering toward desiccation- and pollution-tolerant lichen species, the urban landscape contributed unique lichen species to the region, increasing WNY’s overall lichen biodiversity as much as the relatively pristine Allegheny Plateau. Hence, the urbanized areas of WNY contribute unique species to the regional lichen flora.

Elemental compositions of lichens from Duolun County, Inner Mongolia, China: Origin, road effect and species difference

To assess the response of lichen elemental compositions to road traffic and species difference in the context of high dust input and anthropogenic emissions, two foliose epiphytic lichens (Phaeophyscia hirtuosa, PHh; Candelaria fibrosa, CAf) were sampled near a road adjacent to Dolon Nor Town (Duolun County, Inner Mongolia, China). Twenty elements (Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Sr, Ti, V and Zn) in lichen and surface soil samples were analysed using inductively coupled plasma mass spectrometer (ICP-MS). The results demonstrate that lichen elemental compositions are highly influenced by both their natural environment and anthropogenic input. Windblown dust associated with sand dunes and degraded/desertified steppes represents the predominant source of lichen elements. Road traffic can enhance the lichen elemental burden by increasing the number of soil particles. Anthropogenic emissions from the town and road traffic have also led to the enrichment of Cd and Zn in lichens. PHh was higher than CAf in concentrations of 14 terrigenous metals. Both lichens are applicable to biomonitoring of atmospheric element deposition and, in most cases, yield comparable results.