Search Results (202)

Deforestation driven by plantations, such as Pinus patula Schiede ex Schltdl. et Cham., is a major cause of biodiversity and functional loss in tropical ecosystems. We assessed the diversity and composition of lichens and bryophytes in four size categories of pine cones, small (3–5 cm), medium (5.1–8 cm), large (8.1–10 cm), and very large (10.1–13 cm), with a total of 150 pine cones examined, where the occurrence and cover of lichen and bryophyte species were recorded. Identification keys based on morpho-anatomical features were used to identify lichens and bryophytes. In addition, for lichens, secondary metabolites were tested using spot reactions with potassium hydroxide, commercial bleach, and Lugol’s solution, and by examining the specimens under ultraviolet light. To evaluate the effect of pine cone size on species richness, the Kruskal–Wallis test was conducted, and species composition among cones sizes was compared using multivariate analysis. A total of 48 taxa were recorded on cones, including 41 lichens and 7 bryophytes. A total of 39 species were found on very large cones, 37 species on large cones, 35 species on medium cones, and 24 species on small cones. This is comparable to the diversity found in epiphytic communities of pine plantations. Species composition was influenced by pine cone size, differing from small in comparison with very large ones. The PERMANOVA analyses revealed that lichen and bryophyte composition varied significantly among the pine cone categories, explaining 21% of the variance. Very large cones with specific characteristics harbored different communities than those on small pine cones. The presence of lichen and bryophyte species on the pine cones from managed Ecuadorian P. patula plantations may serve as refugia for the conservation of biodiversity. Pine cones and their scales (which range from 102 to 210 per cone) may facilitate colonization of new areas by dispersal agents such as birds and rodents. The scales often harbor lichen and bryophyte propagules as well as intact thalli, which can be effectively dispersed, when the cones are moved. The prolonged presence of pine cones in the environment further enhances their role as possible dispersal substrates over extended periods. To our knowledge, this is the first study worldwide to examine pine cones as substrates for lichens and bryophytes, providing novel insights into their potential role as microhabitats within P. patula plantations and forest landscapes across both temperate and tropical zones. Full article

Background/Objective: Oral lichen planus (OLP) is a chronic inflammatory disorder of the oral mucosa with unclear etiology. Increasing evidence implicates oral microbial dysbiosis in its pathogenesis, but little is known about supragingival plaque communities in relation to clinical subtypes. This cross-sectional case–control study aimed to characterize the supragingival plaque microbiota and microbial interaction networks in erosive OLP (E-OLP), non-erosive OLP (NE-OLP), and healthy controls (HCs), to elucidate microbial patterns associated with disease severity. Methods: Supragingival plaque samples were collected from 90 participants (30 per group) and analyzed using 16S rRNA gene sequencing. Alpha and beta diversity metrics, differential abundance, and co-occurrence network analyses were performed. Results: E-OLP exhibited pronounced dysbiosis, including the enrichment of pro-inflammatory taxa (e.g., Prevotella, Parvimonas) and depletion of health-associated commensals (e.g., Rothia, Capnocytophaga). Network analysis revealed the stepwise disintegration of microbial community structure from HC to NE-OLP to E-OLP, with reduced connectivity and increased dominance of pathogenic clusters in E-OLP. These microbial alterations aligned with clinical findings, as E-OLP patients showed significantly higher Reticulation/keratosis, Erythema, and Ulceration (REU) scores for erythema and ulceration compared to NE-OLP. Conclusions: Supragingival plaque dysbiosis and ecological disruption are strongly associated with OLP severity and subtype. This study highlights the utility of plaque-based microbial profiling in capturing lesion-proximal dysbiotic signals, which may complement mucosal and salivary analyses in future diagnostic frameworks. Multi-omics approaches incorporating fungal, viral, and metabolic profiling are warranted to fully elucidate host–microbe interactions in OLP. Full article

Ochrolechia is a diverse and charismatic lineage of both sexually and asexually reproducing lichens, with centers of species richness in northern temperate areas of the world, including North America. As part of recent work to comprehensively inventory the lichens of the Indian Peaks Wilderness (Arapaho–Roosevelt National Forest, Front Range Mountains, Colorado), we discovered material of a sorediate member of the genus to which no existing names could be applied. This material was collected in very remote, extremely difficult-to-access mid-montane forests of the west slope of the Indian Peaks Wilderness, in a steep and jagged off-trail drainage (Hell Canyon). Subsequent study of this material along with review of pre-existing collections at the COLO Herbarium revealed it to represent a new scientific species. We here formally describe Ochrolechia raynori, in honor of Seth Raynor who led the Indian Peaks Wilderness lichen inventory. We additionally document the occurrence of Dactylospora parasitica on this new lichen species. Ochrolechia raynori is distinctive for its continuous, smooth, shiny thallus that bears discrete soralia and coarse soredia, its occurrence on mosses and other lichens that overgrow rocks, and its chemistry. We generated a molecular phylogeny of this and other members of Ochrolechia using the nrITS locus and show O. raynori to be sister to the widespread, sexually reproducing species O. upsaliensis. This occurrence of an asexual species that is sister to a sexual species is consistent with the “species pair” hypothesis in lichenology, which suggests an intimate role of reproductive mode divergence in the process of speciation. Examination of the phylogeny yielded evidence of four additional pairs in Ochrolechia, for a total of five species pairs, which indicates that this phenomenon may be a common occurrence in this lineage. IUCN Conservation Assessment of Ochrolechia raynori revealed the species to be best considered as Critically Endangered. However, we expect that continued efforts to inventory the lichens of the southern Rocky Mountains, especially in some of its wildest, most remote regions in similar habitats, will likely result in the discovery of additional populations of this remarkable new species. Full article

Lichens, symbiotic organisms with a high tolerance to harsh environments, possess a greater diversity of sterols than other organisms. Sterols are involved in maintaining membrane integrity, hormone biosynthesis, and signal transduction. (1) Background: A characteristic feature of lichen sterols is a high degree of unsaturation, which influences membrane properties. Desaturases play an important role in the synthesis of unsaturated sterols, in particular, sterol C-5 desaturase (ERG3), which controls the conversion of episterol to ergosterol. Earlier, we demonstrated that the treatment of the lichen Peltigera canina with low and elevated temperatures results in changes in the levels of episterol and ergosterol. (2) Methods: Here, for the first time, we identified ERG3 in P. canina and, using an in silico analysis, we showed that PcERG3 belongs to the superfamily of fatty acid hydrolyases. A phylogenetic analysis was conducted to determine the evolutionary relationships of PcERG3. (3) Results: A phylogenetic analysis showed that PcERG3 clusters with ERG3 from other Peltigeralian and non-Peltigeralian lichens and also with ERG3 from free-living fungi. This suggests that PcERG3 has an ancient evolutionary origin and is related to fungi with lichenized ancestors, e.g., Penicillium. The differential expression of PcERG3 in response to temperature stress, a dehydration/rehydration cycle, and heavy metal exposure suggests that it plays a crucial role in maintaining the balance between more and less saturated sterols and, more generally, in membrane functioning. The multifaceted response of P. canina to abiotic stresses was documented by simultaneously measuring changes in the expression of PcERG3, as well as the genes encoding the heat shock proteins, PcHSP20 and PcHSP98, and PcSOD1, which encodes the antioxidant enzyme superoxide dismutase. (4) Conclusions: These findings suggest that PcERG3 is similar to the sterol C-5 desaturases from related and free-living fungi and plays important roles in the molecular mechanisms underlying the tolerance of lichens to environmental stress. Full article

The Antarctic continent hosts highly specialized microbial ecosystems, particularly within endolithic habitats, where microorganisms colonize the interior of rocks in order to withstand conditions that otherwise cannot support life. Previous studies have characterized the composition and abundance of these communities, as well as their different degrees of stress power; furthermore, the effect of different lithic substrates in shaping their associated bacterial assemblages has been extensively investigated. By contrast, how rock typology exerts fungal endolithic colonization still remains unexplored. In this study, we have considered and compared fungal communities inhabiting granite and sandstone rocks collected across Victoria Land, Antarctica, using high-throughput sequencing of the Internal Transcribed Spacer (ITS) region. Our analyses revealed that both rock types were dominated by Ascomycota, with a marked prevalence of lichen-forming fungi, particularly within the class Lecanoromycetes. However, granite-supported communities exhibited significantly higher species richness, likely driven by the structural heterogeneity of the substrate and the presence of fissures enabling chasmoendolithic colonization. In contrast, sandstone communities were more specialized and dominated by strict cryptoendolithic taxa capable of surviving within the rock’s pore spaces. Differential abundance analysis identified key species associated with each substrate, including the lichen Buellia frigida in granite and the black fungus Friedmanniomyces endolithicus in sandstone, two endemic species in Antarctica. Moreover, the use of presence/absence- versus abundance-based diversity metrics revealed contrasting ecological patterns; substrate type had a stronger influence on species presence, whereas geographic location more significantly shaped abundance profiles, highlighting the complex interplay between both factors in determining fungal community composition. Additionally, alpha diversity analyses showed significantly higher species richness in granite compared to sandstone, suggesting that structural heterogeneity and chasmoendolithism may promote a more diverse fungal assemblage. Full article

Atmospheric emissions of industrial-origin trace metals are a major environmental problem that negatively affects air quality and the functioning of forest ecosystems. Traditional air quality monitoring methods require investments in equipment and infrastructure. Indeed, it is difficult to measure most of these pollutants because their concentrations usually occur at very low levels. However, this study explores an ecological approach for low-cost air quality biomonitoring that is based on native biological indicators in the context of the Mediterranean basin. This study aims (i) to evaluate the lichen species composition, diversity, and distribution across three distinct forest sites; (ii) investigate the relationship between lichen species richness and proximity to the pollution source; and (iii) evaluate heavy metal bioaccumulation using a moss species (Funaria hygrometrica) and a lichen species (Xanthoria parietina) as bioindicators of atmospheric pollution. High concentrations of toxic metals were observed along the transect and closer to the pollutant source with marked interspecies variability. X. parietina exhibited high bioaccumulation potential for most toxic metals (Fe, Zn, Pb, Cr, Cu, and Ni) compared to F. hygrometrica with concentrations varying across the three sites, reaching maximum dry-mass values of 6289 µg/g for Fe at the first site and 226 µg/g for Zn at Site 3. Our results suggest that X. parietina can be used as a potential bioindicator for long-term spatial biomonitoring of air quality by determining atmospheric toxic metals concentrations. Full article

Lasers are widely employed in the treatment of melanocytic lesions. This scoping review evaluates 77 studies on the efficacy and safety of laser treatments for café-au-lait macules (CALMs), nevus of Ota (NOA), Becker’s nevus (BN), lichen planus pigmentosus (LPP), and other pigmented lesions. The Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG), particularly the 1064 nm, is the most frequently utilized laser, demonstrating strong efficacy for NOA and other dermal pigmentary disorders. Medium-wavelength lasers, including the Q-switched ruby and Alexandrite lasers, also show promise, though results vary based on lesion depth, skin type, and treatment protocols. Recurrence and adverse effects, including post-inflammatory hyperpigmentation (PIH) and hypopigmentation, are common, particularly in patients with darker skin tones. Future studies should standardize and optimize laser parameters across lesion types and skin tones, improve long-term efficacy, and prioritize inclusion of patients with diverse Fitzpatrick skin types to evaluate differential outcomes and promote equitable treatment efficacy. Full article

Biodeterioration poses a significant challenge in the conservation of cultural heritage, particularly for earthen sites in humid environments, which are highly susceptible due to their inherent material properties. To address the diverse biological threats affecting such sites, we developed a novel broad-spectrum biocide, FACA, formulated by combining phenylcarbamoylthiazoles and isothiaquinolones to achieve triple efficacy: antimicrobial, anti-algal, and anti-lichen effects. Laboratory assessments demonstrated FACA’s rapid efficacy in eliminating molds, algae, and lichens. A 12-month field application at the Sanyangzhuang earthen site (Neihuang, Henan) yielded excellent results, confirming long-term protection against biological colonization without recurrence. Crucially, the treatment exhibited no adverse effects on the earthen sites, enabling sustainable coexistence between the heritage site and its surrounding ecosystem. These findings support the applicability of FACA for surface treatment across various humid earthen archeological sites. Full article

Retention forestry creates anthropogenic ecotones that diversify forest landscapes in terms of age and biomass. Such diversification can have ambiguous ecological impacts, raising uncertainties, particularly for black alder swamp woodlands, which are considered sensitive and are prioritized in EU conservation policy. This study aimed to examine the effects of adjacent clear-cutting on ground cover vegetation in 12 black alder stands in the hemiboreal zone in Latvia 11 to 120 years since the harvest. Ground cover vegetation was recorded by species along 40 m transects. The effects of the time since adjacent stand harvesting and exposure to the edge on species richness and Shannon diversity were assessed using linear mixed-effects models. A detrended correspondence analysis was used to explore the main environmental gradients. A total of 103 species were recorded: 15 in the tree and shrub layer, 66 in the herbaceous layer, and 22 in the moss and lichen layer. The exposure to the adjacent stand had a moderate positive effect on species diversity, while the effects of edge age were complex and varied by stand type. The scale of disturbance (the absolute length of the analyzed edge), rather than edge age or exposure, had the most pronounced effect on ground cover vegetation composition, suggesting persistent secondary edge effects that should be considered in forest management and conservation planning. Full article

Lichenized fungi, recognized as an ecologically vital and pharmaceutically promising resource, hold substantial value in both environmental conservation and medicinal applications. As the second largest subclass within the lichen-forming fungi of Lecanoromycetes, Ostropomycetidae emerged as a critical reservoir of bioactive secondary metabolites. Current research has revealed that these secondary metabolites demonstrate remarkable bioactivities, positioning them as potential sources for novel pharmaceutical compounds. Despite considerable progress in characterizing chemical constituents and evaluating bioactivities within this subclass, a systematic summary of these discoveries remains absent. This review synthesizes the lichenochemical research progress, providing critical evaluations of 202 structurally characterized compounds from Ostropomycetidae lichen species over recent decades. These Ostropomycetidae-derived compounds cover the phenols, polyketides, fatty acids, terpenoids, steroids, and non-ribosomal peptides, and exhibit diverse bioactivities including antitumor, anti-inflammatory, antibacterial, antifungal, antiviral, antioxidant, anti-angiogenic, anti-neurodegenerative diseases, antitubercular, anti-herbivore, and antitrypanosomal, and so on. The aim of this review is to establish a robust chemodiversity framework and to offer strategic guidance for targeted exploration of lichen-derived drug candidates in the biological resources of Ostropomycetidae lichens. Full article

Lichens that inhabit the roofs of historic buildings create a unique ecosystem. Comprehending the mechanisms underlying lichen colonization and the associated biodegradation within these structures is essential for formulating effective conservation strategies for historic buildings. Here, the microbial communities of lichens on the roofs of 10 historic buildings in Luoyang and nine surrounding counties were investigated via visual assessments and molecular biological analyses. The diversity of lichen species and their biological degradation effects on brick carvings on roof ridges were examined. The findings indicate that both the matrix characteristics of brick carvings and the climatic conditions in Luoyang facilitate the aggregation of lichen communities within these architectural features. Molecular biological tests revealed that Cyanobacteria, Bacillus, Chlorococcus, and Micromonosporaceae were among the most frequently detected bacterial taxa associated with lichens. The fungal associates included Cladosporium and Aspergillus. The infiltration patterns exhibited by certain lichen mycelia correlated with the structural properties at the interface between lichens and brick carvings, allowing mycelial penetration into the interior of these bricks. Additionally, guano not only serves as an organic nutrient source for microbial proliferation but also is a transmission medium for lichen-associated microorganisms residing on roof brick carvings. Whilst there are slight variations in microbial composition among lichens found in mountains and hilly areas around Luoyang, their colonization behaviors and degradation patterns are similar to those observed in analogous communities across different microclimate zones. The results offer a robust theoretical foundation for mitigating lichen-induced bioerosion in the historical buildings of Luoyang and serve as a valuable reference for the sustainable preservation of cultural heritage. Full article

Epiphytic organisms are characteristic elements of the Andean dry forest, playing a crucial role in ecosystem diversity and functionality, but they are threatened by deforestation-related factors. The diversity of epiphytic lichens and bryophytes was recorded in the Pisaca Reserve, which has an artificial pond locally known as “Laguna Pisaca”, serving as a critical micro-watershed. This pond provides water services to the city of Catacocha, motivating local communities to protect its biodiversity. In each zone (low, middle and high), 10 plots of 5 × 5 m were established, where the presence and coverage of lichens and bryophytes were sampled in 4 trees per plot (120 trees). Richness and diversity (Shannon–Weaver and Simpson indices) were calculated. Generalized linear models (GLM) were used to analyze the effect of the zone on richness and diversity, and multivariate analysis was used to analyze species composition. A total of 90 species were recorded (65 lichens and 25 bryophytes), distributed in three zones: 74 in the high, 67 in the low and 41 in the middle zone. Species richness and composition showed significant variations in relation to the three zones, influenced by forest structure, small altitudinal changes and forests disturbance. The forests of the Pisaca Reserve harbor a great diversity of lichens and epiphytic bryophytes, which serve as refuges for biodiversity in the Andean dry montane forest of South Ecuador. Full article

Retention forestry is the dominant practice in Northern Europe, with large-scale clear-cuts following natural disturbances becoming more frequent as the climate changes. Despite its widespread use, clear-cutting is criticized for its potential adverse effects on species diversity and ecosystem recovery, particularly in understory vegetation. This study examines early vegetation changes after large-scale clear-cutting in Latvia’s hemiboreal forests. The sampling was conducted in 2017 and 2020, three and six years post-harvest, using 210 systematically placed plots (1 × 1 m) to assess species abundance and vegetation cover across moss/lichen, herbaceous, and shrub/tree layers. The findings indicate that species diversity was initially higher following clear-cutting but declined after six years, with the herbaceous layer most affected. While clear-cutting temporarily increases species diversity, negative effects become evident over time. Recovery is prolonged, with succession progressing faster in wet areas. To fully understand the long-term impacts of clear-cutting, continued monitoring is necessary. Full article

Lichens are an important vegetative component of the Antarctic terrestrial ecosystem and present a wide diversity. Recent advances in omics technologies have allowed for the identification of lichen microbiomes and the complex symbiotic relationships that contribute to their survival mechanisms under extreme conditions. The preservation of biodiversity and genetic resources is fundamental for the balance of ecosystems and for human and animal health. In order to assess the current knowledge on Antarctic lichens, we carried out a systematic review of the international applied research published between January 2019 and February 2024, using the PRISMA model (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Articles that included the descriptors “lichen” and “Antarctic” were gathered from the web, and a total of 110 and 614 publications were retrieved from PubMed and ScienceDirect, respectively. From those, 109 publications were selected and grouped according to their main research characteristics, namely, (i) biodiversity, ecology and conservation; (ii) biomonitoring and environmental health; (iii) biotechnology and metabolism; (iv) climate change; (v) evolution and taxonomy; (vi) reviews; and (vii) symbiosis. Several topics were related to the discovery of secondary metabolites with potential for treating neurodegenerative, cancer and metabolic diseases, besides compounds with antimicrobial activity. Survival mechanisms under extreme environmental conditions were also addressed in many studies, as well as research that explored the lichen-associated microbiome, its biodiversity, and its use in biomonitoring and climate change, and reviews. The main findings of these studies are discussed, as well as common themes and perspectives. Full article

Lichens are an important source of diverse and unique secondary metabolites with recognized biological activities through experimental and computational procedures. The objective of this study is to investigate the metabolomic profile of the ethanolic extract of the Antarctic lichen Gondwania regalis and evaluate its antioxidant and antidiabetic activities with in vitro, in silico, and molecular dynamics simulations. Twenty-one compounds were tentatively identified for the first time using UHPLC/ESI/QToF/MS in negative mode. For antioxidant activity, the DPPH assay showed an IC₅₀ value of 2246.149 µg/mL; the total phenolic content was 31.9 mg GAE/g, the ORAC assay was 13.463 µmol Trolox/g, and the FRAP assay revealed 6.802 µmol Trolox/g. Regarding antidiabetic activity, enzyme inhibition yielded IC₅₀ values of 326.4513 µg/mL for pancreatic lipase, 19.49 µg/mL for α-glucosidase, and 585.216 µg/mL for α-amylase. Molecular docking identified sekikaic acid as the most promising compound, with strong binding affinities to catalytic sites, while molecular dynamics confirmed its stability and interactions. Toxicological and pharmacokinetic analyses supported its drug-like potential without significant risks. These findings suggest that the ethanolic extract of Gondwania regalis is a promising source of bioactive compounds for developing natural antioxidant and antidiabetic therapies. Full article