Search Results (5)

Recent studies actively debate oxic methane (CH₄) production processes in water and terrestrial ecosystems. This previously unknown source of CH₄ on a regional and global scale has the potential to alter our understanding of climate-driving processes in vulnerable ecosystems, particularly high-latitude ecosystems. Thus, the main objective of this study is to use the incubation approach to explore possible greenhouse gas (GHG) fluxes by the most widely distributed species of epiphytic lichens (ELs; Evernia mesomorpha Nyl. and Bryoria simplicior (Vain.) Brodo et D. Hawksw.) in the permafrost zone of Central Siberia. We observed CH₄ production by hydrated (50%–400% of thallus water content) ELs during 2 h incubation under illumination. Moreover, in agreement with other studies, we found evidence that oxic CH₄ production by Els is linked to the CO₂ photoassimilation process, and the EL thallus water content regulates that relationship. Although the GHG fluxes presented here were obtained under a controlled environment and are probably not representative of actual emissions in the field, more research is needed to fully comprehend ELs’ function in the C cycle. This particular research provides a solid foundation for future studies into the role of ELs in the C cycle of permafrost forest ecosystems under ongoing climate change (as non-methanogenesis processes in oxic environments). Full article

Despite their small size, cryptogams (lichen, liverwort, and moss) are important for ecosystem stability. Due to their strong stress resistance, cryptogams often cover extreme environments uninhabitable for vascular plants, which has an important impact on the material cycle and energy flow of various terrestrial ecosystems. In this article, we review and discuss the effects of cryptogams on soil properties (moisture and fertility) and vascular plant regeneration over the past two decades. Cryptogams strongly affect soil water content by influencing precipitation infiltration, non-rainfall water input, soil evaporation, soil water holding capacity, and soil permeability, ultimately helping to reduce soil water content in areas with low annual precipitation (<500 mm). However, in areas with high annual precipitation (>600 mm) or where the soil has other water sources, the presence of cryptograms is conducive to soil water accumulation. Cryptogam plants can increase soil fertility and the availability of soil nutrients (TOC, TN, TP, TK, and micronutrients) in harsh environments, but their effects in mild environments have not been sufficiently investigated. Cryptogam plants exert complex effects on vascular plant regeneration in different environments. The primary influence pathways include the physical barrier of seed distribution, shading, allelopathy, competition, influences on ectomycorrhizal development and individual reproduction, and the regulation of soil water content, temperature, and nutrients. Full article

This work represents the first study of the floristic diversity on Bulgaria’s ancient mounds. The objective of this research was to assess the importance of the mounds for the preservation of the native vascular and cryptogam flora. Our sampling design included 111 ancient mounds distributed throughout the country. We recorded a total of 1059 vascular plants, 58 bryophytes and 61 lichen taxa. Despite their small area, the mounds were shown to preserve nearly a quarter of the Bulgarian flora. The vegetation cover on the mounds included 61% perennials indicating a long-term persistence and stability. The majority (98%) of the established vascular plants were native species. Although the conservation significance of the vascular plant species were not common, we recorded 2 critically endangered, 9 endangered and 14 Balkan endemics during the present study. The lichen Arthopyrenia salicis was recorded for the first time in Bulgaria and a new locality of the rare bryophyte Ceratodon conicus was discovered. The established compositional difference between plots from the northern and southern slopes of the mounds (88.95%) is a testament to the high local habitat diversity. The prevalence of species characteristic for Festuco-Brometea suggests that the mounds preserve fragments of native grasslands and steppes. The variation in cover of agricultural and other human modified areas in the mounds’ immediate surroundings did not substantially affect their species richness. We argue that the ancient mounds should be taken into consideration in future green space planning. Full article

Air pollution is one of the main environmental problems in developed and developing countries. Epiphytic cryptogams (bryophytes and lichens) are proposed as a reliable indicator to detect environmental changes, given to their sensitivity to pollutants. In this study we evaluated air quality in the city of Ambato using bryophytes and epiphytic lichens on three land uses (urban, peri-urban and control). In each zone we selected ten trees (a total of 90 trees) for each station (a total of nine stations), where we recorded the frequency and cover of epiphytic cryptogams in a quadrat of 10 × 50 cm that was divided into 5 × 5 cm squares. Differences in richness, index of atmospheric purity (IAP) and diversity were analyzed using a generalized linear model (GLM) and changes in species composition using multivariate analysis. We recorded 39 species of cryptogams (25 lichens and 14 bryophytes). Richness, diversity and index of atmospheric purity were higher in the control zone compared to the urbanized zones. Community composition changed between the different zones, with increasing differences between the control and urban zones. The urban areas of the city of Ambato were identified with high levels of air pollution due to their lower diversity related to higher vehicular traffic and industrial activities (e.g., footwear and textile factories, tanneries). Thus, epiphytic cryptogams are a fast and low-cost method for air quality assessment in tropical areas. Full article

Potash tailing piles located in Germany represent extremely hypersaline locations that negatively affect neighbouring environments and limit the development of higher vegetation. However, biocrusts, as cryptogamic covers, inhabit some of these areas and provide essential ecological functions, but, nevertheless, they remain poorly described. Here, we applied high-throughput sequencing (HTS) and targeted four groups of microorganisms: bacteria, cyanobacteria, fungi and other eukaryotes. The sequencing of the 16S rRNA gene revealed the dominance of Proteobacteria, Cyanobacteria and Actinobacteria. Additionally, we applied yanobacteria-specific primers for a detailed assessment of the cyanobacterial community, which was dominated by members of the filamentous orders Synechococcales and Oscillatoriales. Furthermore, the majority of reads in the studied biocrusts obtained by sequencing of the 18S rRNA gene belonged to eukaryotic microalgae. In addition, sequencing of the internal rDNA transcribed spacer region (ITS) showed the dominance of Ascomycota within the fungal community. Overall, these molecular data provided the first detailed overview of microorganisms associated with biocrusts inhabiting highly saline potash tailing piles and showed the dissimilarities in microbial diversity among the samples. Full article