Accurate estimation of cryptogam biomass, encompassing bryophytes and lichens, is crucial for understanding their ecological significance. This estimation is conducted based on the strong correlations between mass and volume of cryptogams. However, mass-volume correlations vary among cryptogams because of their morphological differences. This problem can be solved using models that consider life forms that classify cryptogams based on morphological similarities. In this study, we investigated whether life form models improve cryptogam biomass estimation accuracy. The cryptogam mass-volume correlation of each life form was estimated using Bayesian linear models. The coefficients and intercepts of linear models differed between life forms, which was attributed to the morphological characteristics of each life form. Therefore, life form models can improve the accuracy of estimation models by incorporating morphological differences. However, taxonomic models that consider only the taxonomic difference (bryophytes vs lichens) demonstrated better overall estimation than the life form models, probably because of the ability of taxonomic models to capture systematic differences between bryophytes and lichens. Furthermore, these models may mitigate estimation errors related to morphological variations that cannot be adequately represented by life form types. Based on these results, we propose the appropriate use of estimation models.

Climate change significantly impacts the distribution of woody plants, indirectly influencing the dynamics of entire ecosystems. Understanding species\' varied responses to the environment and their reliance on biotic interactions is crucial for predicting the global changes\' impact on woodland biodiversity. Our study focusses on Dicranum viride, a moss of conservation priority, and its dependence on specific phorophytes (host trees). Using species distribution modelling (SDM) techniques, we initially modelled its distribution using climate-only variables. As a novel approach, we also modelled the distribution of the main phorophyte species and incorporated them into D. viride SDM alongside climate data. Finally, we analysed the overlap of climatic and geographic niches between the epiphyte and the phorophytes. Inclusion of biotic interactions significantly improved model performance, with phorophyte availability emerging as the primary predictor. This underscores the significance of epiphyte-phorophyte interactions, supported by substantial niche overlap. Predictions indicate a potential decline in the suitability of most of the current areas for D. viride, with noticeable shifts towards the northern regions of Europe. Our study underscores the importance of incorporating biotic interactions into SDMs, especially for dependent organisms. Understanding such connections is essential to implement successful conservation strategies and adapt forest management practices to environmental changes.

The hyperaccumulation potential of zinc (Zn) and cadmium (Cd) and their synergistic effects were examined in relation to Christmas moss (Vesicularia montagnei (Bél) Broth., Hypnaceae), an aquatic and terrestrial moss, dosed with Cd (Cd1 and Cd2), Zn (Zn1 and Zn2) and combined Zn and Cd (Cd1Zn1 and Cd2Zn2). Zinc promoted plant growth and development, particularly in the highest Zn and combined Zn/Cd treatments (Zn2 and Cd2Zn2). The Zn treatment resulted in substantial moss chlorophyll content and highest percentage relative growth rate in biomass value (0.23 mg L-1 and 106.8%, respectively); however, the Cd2Zn2 treatment achieved maximal production of chlorophyll a and total chlorophyll (0.29 and 0.51 mg L-1, respectively) due to synergistic effects. These findings suggest that Christmas moss is a highly metal-tolerant and adaptable bryophyte species. Zinc was essential for reducing the detrimental effects of Cd while simultaneously promoting moss growth and biomass development. Furthermore, Christmas moss exhibited hyperaccumulation potential for Cd and Zn in the Cd2Zn2 and Zn alone treatments, as evidenced by highest Cd and Zn values in gametophores (1002 and 18,596 mg per colony volume, respectively). Using energy dispersive X-ray fluorescence (EDXRF) spectrometry, atomic percentages of element concentrations in moss gametophores in the Zn2, Cd2 and combined Zn/Cd treatments were generally in the order: K > Ca > P > Zn > Cd. When comparing the atomic percentages of Zn and Cd in gametophores, it is likely that the higher atomic percentage of Zn was because this element is essential for plant growth and development.

Extending the network of strict forest reserves is one of the conservation measures promoted by the French National Strategy for Biodiversity. However, there is a lack of evidence concerning the efficiency of setting aside strict forest reserves to preserve biodiversity in the case of temperate forests. Moreover, there are potentially unexplored underlying ecological mechanisms that forest management could usefully mimic. In order to disentangle the respective roles of management abandonment, stand structural attributes and climatic and topographic variables in determining forest biodiversity, we conducted the first national-scale study in France comparing biodiversity in managed and in unmanaged forests. Here we focus on bryophytes (all species combined and forest specialists separately). We analyzed data from 127 plots in ten lowland forests in France. Our aim was to disentangle the relationships between bryophyte richness and (i) management abandonment per se, (ii) associated forest-structure variables like deadwood volume, and (iii) macroclimatic variables important for bryophytes (temperature, precipitation, relative humidity, solar radiation and vapor pressure deficit). For each studied combination of variables (univariate, additive or interactive models), we compared hierarchical models of several types: linear with a fixed slope, linear with a random slope, quadratic, sigmoid or threshold models. We found that deadwood variables were the main drivers of bryophyte richness in managed as well as in unmanaged stands. We observed a sigmoid relationship of total deadwood volume to overall richness, and a threshold effect of large and very large deadwood volume on forest specialist richness. The effect of management abandonment was globally non-significant, though impact varied strongly among the different forest sites. A combination of deadwood and macroclimatic variables best predicted bryophyte richness, through non-linear relationships: 1) higher solar radiation reinforced the positive effects of large deadwood on forest-specialist bryophyte richness; and 2) higher mean annual temperatures counteracted the positive effects of total deadwood amount on total bryophyte species richness. Maintaining high amounts of deadwood in both managed and unmanaged forests is likely to improve bryophyte richness and will be particularly important under ongoing climate change.

Glacier mice are peculiar rolling or stationary moss balls found on the surface of some glaciers. They may harbour an ecological habitat for cold-adapted invertebrates and microorganisms, but little is known about their potential to accumulate and disseminate harmful elements and substances. In this study, we investigate the presence of fallout radionuclides (137Cs, 238Pu, 239Pu, 240Pu, 210Pb) and heavy metals (Pb, As, Hg, Cd) in glacier mice and compare the results to bryophytes from adjacent glacier ecosystems. Samples were collected at Austerdalsbreen, a Norwegian outlet glacier from Jostedalsbreen ice cap. Maximum activity concentrations for bryophytes are 552 ± 12 Bq kg-1 for 137Cs, 3485 ± 138 Bq kg-1 for 210Pb, 0.0223 ± 0.065 Bq kg-1 for 238Pu and 4.34 ± 0.43 Bq kg-1 for 239+240Pu while maximum heavy metals concentrations are 70.5 mg kg-1 for Pb, 1.0 mg kg-1 for As, 1.6 mg kg-1 for Hg and 0.13 mg kg-1 for Cd. Maximum activity concentrations in cryconite are 1973.4 ± 5.0 Bq kg-1 for 137Cs, 3632 ± 593 Bq kg-1 for 210Pb, 0.51 ± 0.11 Bq kg-1 for 238Pu and 13.1 ± 1.4 Bq kg-1 for 239+240Pu and maximum heavy metal concentrations are 50.4 mg kg-1 for Pb, 3.4 mg kg-1 for As, 1.5 mg kg-1 for Hg and 0.082 mg kg-1 for Cd. We find that glacier mice show lower activity concentrations of radionuclides compared to cryoconite. The major source of plutonium isotopes is related to global fallout, whereas detected radio-cesium may be additionally affected by post-Chernobyl fallout to an unknown extent. Comparison between glacier surface and adjacent glacial habitats shows higher concentrations of heavy metals in glacier mice on the glacier ice surface and medial moraines compared to bryophytes in the glacier forefield. Glacier mice exported from a receding glacier may affect the cycling of radioactive and metal pollutants in developing proglacial ecosystems.

Rhodobryum giganteum (Bryaceae, Bryophyta), a rare medicinal bryophyte, is valued for its cardiovascular therapeutic properties in traditional Chinese medicine. This study presents the first complete chloroplast genome sequence of R. giganteum, including its assembly and annotation. The circular chloroplast genome of R. giganteum is 124,315 bp in length, displaying a typical quadripartite structure with 128 genes: 83 protein-coding genes, 37 tRNAs, and 8 rRNAs. Analyses of codon usage bias, repetitive sequences, and simple sequence repeats (SSRs) revealed an A/U-ending codon preference, 96 repetitive sequences, and 385 SSRs in the R. giganteum chloroplast genome. Nucleotide diversity analysis identified 10 high mutational hotspots. Ka/Ks ratio analysis suggested potential positive selection in rpl20, rps18, petG, and psbM genes. Phylogenetic analysis of whole chloroplast genomes from 38 moss species positioned R. giganteum within Bryales, closely related to Rhodobryum laxelimbatum. This study augments the chloroplast genomic data for Bryales and provides a foundation for molecular marker development and genetic diversity analyses in medicinal bryophytes.

Climate change in high latitude regions leads to both higher temperatures and more precipitation but their combined effects on terrestrial ecosystem processes are poorly understood. In nitrogen (N) limited and often moss-dominated tundra and boreal ecosystems, moss-associated N2 fixation is an important process that provides new N. We tested whether high mean annual precipitation enhanced experimental warming effects on growing season N2 fixation in three common arctic-boreal moss species adapted to different moisture conditions and evaluated their N contribution to the landscape level. We measured in situ N2 fixation rates in Hylocomium splendens, Pleurozium schreberi and Sphagnum spp. from June to September in subarctic tundra in Sweden. We exposed mosses occurring along a natural precipitation gradient (mean annual precipitation: 571-1155 mm) to 8 years of experimental summer warming using open-top chambers before our measurements. We modelled species-specific seasonal N input to the ecosystem at the colony and landscape level. Higher mean annual precipitation clearly increased N2 fixation, especially during peak growing season and in feather mosses. For Sphagnum-associated N2 fixation, high mean annual precipitation reversed a small negative warming response. By contrast, in the dry-adapted feather moss species higher mean annual precipitation led to negative warming effects. Modelled total growing season N inputs for Sphagnum spp. colonies were two to three times that of feather mosses at an area basis. However, at the landscape level where feather mosses were more abundant, they contributed 50% more N than Sphagnum. The discrepancy between modelled estimates of species-specific N input via N2 fixation at the moss core versus ecosystem scale, exemplify how moss cover is essential for evaluating impact of altered N2 fixation. Importantly, combined effects of warming and higher mean annual precipitation may not lead to similar responses across moss species, which could affect moss fitness and their abilities to buffer environmental changes.

The selection of the appropriate biomonitor species is a crucial criterion for biomonitoring on a broad spatial scale. Mosses Hypnum cupressiforme and Brachythecium spp. and lichen Evernia prunastri were sampled at 22 remote sites over Serbia aiming interspecies comparison of their bioconcentration capacities. The concentration of 16 potentially toxic elements (PTEs), Al, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, P, Pb, S, Sr, V, and Zn, was measured in the samples. Between the co-located mosses, linear regression analysis (type II) showed significant determination coefficients only for a couple of the elements (Cd and S), while for H. cupressiforme vs. lichen, significant regression lines were obtained for a broader set of elements (Ba, Cd, Fe, Hg, Mn, Ni, Sr). The ratio of the PTEs in the mosses discovered higher concentrations in H. cupressiforme than in another moss at some sites and vice versa at other sites. According to the PTE ratios, H. cupressiforme accumulated much more element content than the lichen, but followed a similar spatial pattern. In addition, principal component analysis (PCA) pointed out a different grouping of the PTEs depending on the species tested. The poor correlation of the moss-moss data is perhaps because several species of the genus Brachythecium were sampled, which possibly influenced the average genus accumulation capacity. In addition, morphological features of the mosses (concave vs. flat leaflets, creeping vs. cushiony life form) presumably delegate differences in PTE accumulation. To conclude, it should be careful with using more biomonitor species, even of the same genus, within the same study.

Dicranum Hedw. is a highly diverse and widely distributed genus within Dicranaceae. The species diversity and distribution of this genus in China, however, remain not well known. A new revision of Dicranum in China using morphological and molecular phylogenetic methods confirms that China has 39 species, including four newly reported species, D. bardunovii Tubanova & Ignatova, D. dispersum Engelmark, D. schljakovii Ignatova & Tubanova, and D. spadiceum J.E.Zetterst. Dicranum psathyrum Klazenga is transferred to Dicranoloma (Renauld) Renauld as a new synonym of Dicranoloma fragile Broth. Two species, Dicranum brevifolium (Lindb.) Lindb. and D. viride (Sull. & Lesq.) Lindb. are excluded from the bryoflora of China. A key to the Chinese Dicranum species is also provided. These results indicate an underestimation of the distribution range of numerous Dicranum species, underscoring the need for further in-depth investigations into the worldwide Dicranum diversity.

Peat formation is the key process responsible for carbon sequestration in peatlands. In rich fens, peat is formed by brown mosses and belowground biomass of vascular plants. However, the impact of ecohydrological settings on the contribution of mosses and belowground biomass to peat formation remains an open question. We established seven transects in well-preserved fens in NE Poland along an ecohydrological gradient from mesotrophic sedge-moss communities with stable water levels, to more eutrophic tall sedge communities with higher water level fluctuations. In each transect, we measured the production of brown mosses (using the plug method), aboveground vascular plant biomass (one year after cutting) and belowground biomass (using ingrowth cores). Decomposition rates of all biomass fractions were assessed using litter bags. The first-year surplus of potentially peat-forming fractions, i.e., mosses and belowground biomass, decreased with increasing water level fluctuations and along a vegetation gradient from sedge-moss to tall sedge communities. Moss production was highest in the sedge-moss fen with a stable water level at the ground surface. We did not detect any difference in belowground biomass production across the gradient but found it to be consistently higher in the upper 0-5 cm than in the deeper layers. The decomposition rate also showed no response to the gradient, but differed between biomass types, with aboveground biomass of vascular plants decomposing 2.5 times faster than belowground biomass and mosses. Pattern of peat formation potential along the ecohydrological gradient in rich fen was strongly driven by brown moss production. Sedge-moss fens with a stable water level at the ground surface have the highest peat formation capacity compared to other vegetation types. In the part of the gradient that is poorer in nutrients, vascular plants invest in belowground production, and mosses dominate the aboveground layer.