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Synthesis of silver nanoparticles using extracts from plants is an advantageous technological alternative to the traditional colloidal synthesis due to its simplicity, low cost, and the inclusion of environmentally friendly processes to obtain a new generation of antimicrobial compounds. The work describes the production of silver and iron nanoparticles using sphagnum extract as well as traditional synthesis. Dynamic light scattering (DLS) and laser doppler velocimetry methods, UV-visible spectroscopy, transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), dark-field hyperspectral microscopy, and Fourier-transform infrared spectroscopy (FT-IR) were used to study the structure and properties of synthesized nanoparticles. Our studies demonstrated a high antibacterial activity of the obtained nanoparticles, including the formation of biofilms. Nanoparticles synthesized using sphagnum moss extracts likely have high potential for further research.

We analysed the chemical compositions of snow, soil, and bioindicators (pine bark Pinus sylvestris, Sphagnum fallax moss bags) to assess atmospheric pollution in the vicinity of the Severonickel copper-nickel industrial complex in the Kola Peninsula. We conducted a comparative analysis of mineralogical, geochemical, and physicochemical parameters as well as the metal contents (Ca, Fe, Pb, Zn, Mn, Ni, Cu, Cd, Sc, V, Co, and Ba) of environmental components across a 32-km pollution gradient. The mineralogical and chemical composition of soil, snow aerosols, and Sphagnum fallax moss bags all corresponded to the metallogeny of the research area and the ore specialisation of the enterprise (Ni, Cu, Co, and V). Solid aerosols consisted of rock-forming and accessory minerals as well as technogenic formations (slag particles and aggregates composed of Ni–Fe–Co ± Cu). The concentration of metals in soils, aerosols, snow water, and pine bark significantly exceeded their background values. The reconstruction of new technologies in the Severonickel smelter and recent reduction in emissions did not significantly improve the state of the different landscape components. The calculation of dust, metal, and ionic loads from snow surveys and moss bags showed comparable results. Technogenic emissions were higher in summer due to the increase in atmospheric dust. The low pH of soils and snow water reflected the geochemical conditions of the landscape and increased metal mobility in the environment. The high total content of Ni, Cu, and Co and their mobile forms in soils contributed to the high accumulation of metals in pine bark; this method can therefore be used as an accurate indicator of environmental degradation.

The article summarizes current data about the condition and spread of Sphagnum mosses on the territory of Male Polissya in Lviv Region based on the material from our own field research, materials of National Herbarium of Ukraine (KW), the Herbarium National Museum of Natural History of the National Academy of Sci­ences of Ukraine (LWS) and literature data. An annotated list of the species of the genus Sphagnum was compiled and it includes 15 species together with an indication of place and date of collection, the names of collectors, the spread in Ukraine and biotopes in which the species may occur according to The National Habitat Catalogue of Ukraine and EUNIS. Sphagnum fallax (Klinggr.) Klinggr., S. fimbriatum Wils. and S. palustre L. were determined as the most widespread species of the genus Sphagnum in the research area. Two species S. angustifolium and S. inundatum are indicated for the first time for the territory of Lviv region. Six regionally rare species were found: S. capillifolium, S. cuspidаtum, S. fаllax, S. fimbriаtum, S. obtusum and S. papillosum. The possible disappearance of a species Sphagnum centrale, S. contortum, S. flexuosum and S. obtusum on the territory of the Volytsky Botanical Reserve of national importance was established owing to the draining of wetlands. Ecological groups of sphagnum species on the research area were analyzed, where the predominance of subheliophytes (7 species, 46.7 %), hygrophytes (13 species, 86.7 %), cold tolerant species (13 or 87.7 %) and acidophiles (8 species, 53.3 %) was identified. The topicality of the study is determined by the fact that sphagnum mosses are spread much less frequently than other species from the division of bryophytes because they are confined to a narrow range of biotopes. With the drastic changes in the hydrological regime of the environment, which occurred during the second half of the twentieth century, due to the large areas of drained land, the processes of biotope dehydration became irreversible and some species of sphagnum could have disappeared from the territory of Male Polissya. Due to the sensitivity of bryophytes, in particular species of the sphagnum genus, and due to a disturbance of the hydrological regime of wetlands, the waterlogged mixed coniferous forest in the vicinity of the village Kulychkiv is a promising territory for the creation of a new environmentally protected site or the extension of the Volytsky Botanical Reserve of national importance for the purpose of wetlands preservation here.

Представлены результаты опыта по выявлению влияния некоторых солей на рост Sphagnum fallax в лабораторных условиях. Показано влияние солей в различных концентрациях на скорость роста данного вида мха. Основными параметрами для оценки послужили изменения в общем приросте растений, изменения длины боковых ветвей и диаметра головок., The results of an experiment to identify the effect of certain salts on the growth of Sphagnum fallax in laboratory conditions are presented. The effect of salts in various concentrations on the growth rate of this type of moss isshown. The main parameters for the assessment were changes in the general growth of plants, changes in the length of the lateral branches and the diameter of the heads.

The use of biological indicators of environmental quality is an alternative method of monitoring ecosystem pollution. Various groups of contaminants, including organic ones, can be measured in environmental samples. Polycyclic aromatic hydrocarbons (PAHs) have not yet been determined by the moss bag technique. This technique uses several moss species simultaneously in urban areas to select the best biomonitoring of these compounds, which are dangerous to humans and the environment. In this research, a gas chromatography coupled with mass spectrometry was used for the determination of selected PAHs in three species of mosses: Pleurozium schreberi, Sphagnum fallax and Dicranum polysetum (active biomonitoring) and for comparison using an air filter reference method for atmospheric aerosol monitoring. The chlorophyll fluorescence of photosystem II (PSII) was also measured to assess changes in moss viability during the study. As a result of the study, the selective accumulation of selected PAHs by mosses was found, with Pleurozium schreberi being the best bioindicator—9 out of 13 PAHs compounds were determined in this species. The photosynthetic yield of photosystem (II) decreased by 81% during the exposure time. The relationship between PAHs concentrations in mosses and the total suspended particles (TSP) on the filter indicated the possibility of using this bioindicator to trace PAHs in urban areas and to apply the moss bag technique as a method supporting classical instrumental air monitoring.

Located on the western flank of the Changbai Mountains in Northeast China, Hani (HN) peatland has been studied intensively for Holocene paleoclimate reconstruction on decadal to centennial scales. This study presented new datasets of hydroclimatic controls on the distribution and abundance of mosses through modern vegetation survey and plant macrofossil analysis of a historical peat profile. Survey on the abundance of ten different moss species in 40 vegetation quadrats and their depths to water table (DWT) in the HN mire have been conducted during the growing season (June to October) in 2015 and 2016. Our results indicated that (1) the abundances of these mosses showed close relationship with DWTs; and (2) DWT was a function of local precipitation with lower DWT corresponding to higher precipitation. Sphagnum fallax, S. cuspidatum and S. subsecundum preferred wet microhabitats under higher precipitation (i.e., lower DWT), and vice versa. Hence, the variation in the abundance of these sphagna was considered to be an indicator of changes in precipitation. An equation for quantitative estimation of DWT based on the abundances of the moss species along different moisture habitats has been established based on the modern survey, which was able to reconstruct the variation of DWT in the past from plant macrofossil analysis. A 50 cm core from HN mire was dated by AMS 14C, 210Pb, and 137Cs methods, providing a 50-year record of hydroclimate. Plant macrofossils were identified at 1 cm intervals of the peat core, which exhibited detailed variations of the moss assemblages. The variation of DWT reconstructed from the coverage of S. fallax and the total coverage of S. fallax, S. cuspidatum and S. subsecundum in the core matched well in peak-to-peak and trough-to-trough with local growing season precipitation on annual scale during the past 50 years. Our study suggests that selecting well-responsive Sphagnum species is a key factor to reconstruct hydroclimate by using plant macrofossils.

Sphagnum‐dominated peatlands comprise a globally important pool of soil carbon (C) and are vulnerable to climate change. While peat mosses of the genus Sphagnum are known to harbor diverse microbial communities that mediate C and nitrogen (N) cycling in peatlands, the effects of climate change on Sphagnum microbiome composition and functioning are largely unknown. We investigated the impacts of experimental whole‐ecosystem warming on the Sphagnum moss microbiome, focusing on N2 fixing microorganisms (diazotrophs). To characterize the microbiome response to warming, we performed next‐generation sequencing of small subunit (SSU) rRNA and nitrogenase (nifH) gene amplicons and quantified rates of N2 fixation activity in Sphagnum fallax individuals sampled from experimental enclosures over 2 years in a northern Minnesota, USA bog. The taxonomic diversity of overall microbial communities and diazotroph communities, as well as N2 fixation rates, decreased with warming (p, We combined the use of a unique whole‐ecosystem warming approach coupled with microbial community analyses and functional assessments through two growth seasons. We found microbial diversity and nitrogen fixation decreased with warming treatment.

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species.

Peatlands are one of the most important ecosystems due to their biodiversity and abundant organic compounds; therefore, it is important to observe how different plant species in peatlands react to changing environmental conditions. Sphagnum spp. are the main component of peatlands and are considered as the creator of conditions favorable for carbon storage in the form of peat. Sphagnum angustifolium and Sphagnum fallax are taxonomically very close species. To examine their adaptability to climate change, we studied the morphology and pigment content of these two species from environmental manipulation sites in Poland, where the environment was continuously manipulated for temperature and precipitation. The warming of peat was induced by using infrared heaters, whereas total precipitation was reduced by a curtain that cuts the nighttime precipitation. Morphology of S. angustifolium stayed under climate manipulation relatively stable. However, the main morphological parameters of S. fallax were significantly affected by precipitation reduction. Thus, this study indicates S. angustifolium is better adapted in comparison to S. fallax for drier and warmer conditions.

Litter decomposition is an important source of dissolved organic matter (DOC). In peatlands with hardly degradable soil DOC, the input of DOC from vascular plant litter can represent an important source of nutrients and decomposable substrates for soil microorganisms. We established a laboratory incubation with the litters of three peatland plant dominants (Sphagnum fallax, Vaccinium myrtillus and Eriophorum vaginatum) for 200 days, aiming to study DOC production and its quality. The quality of the DOC leached from the litters was characterized by a distribution of C, N and P among molecular weight (MW) fractions ( 100 kDa), their aromaticity, composition of low molecular weight compounds (organic acids, sugars and amino acids) and DOC biodegradability. The leaves of vascular plants decomposed the fastest, releasing larger amounts of nutrients and easily degradable organic acids, sugars and amino acids to the leachate, when compared to their roots and Sphagnum. DOC distribution to the MW fractions did not differ among the litters. Neither the DOC distribution to the respective fractions nor leachate C/N/P stoichiometry were factors driving DOC biodegradability. Total dissolved P distribution to the MW fractions significantly differed among the litters, with Sphagnum being very specific: P was initially associated only with high molecular weight DOC, while later it was redistributed to the lower MW fractions and complexed with Al and Fe. The complexation may retard soluble reactive P leaching especially from Sphagnum litter. DOC biodegradability was higher for the vascular plant leaf litter than for the Sphagnum litter in the early stages of decomposition (20 days) but later decreased and became more uniform for all litters. These temporal differences (by decomposition stage) were more pronounced than those caused by litter origin. Our results indicate that mainly leaf litter of vascular plants can release significant amounts of DOC during the early stage of decomposition. This DOC is more aromatic with higher biodegradability and more nutrients (especially P) as compared to Sphagnum and can thus temporarily stimulate microbial activity in habitats dominated by the vascular plants.

Peatlands are a critical carbon store comprising 30% of the Earth’s terrestrial soil carbon. Sphagnum mosses comprise up to 90% of peat in the northern hemisphere but impacts of climate change on Sphagnum mosses are poorly understood, limiting development of sustainable peatland management and restoration. This study investigates the effects of elevated atmospheric CO2 (eCO2) (800 ppm) and hydrology on the growth of Sphagnum fallax, Sphagnum capillifolium and Sphagnum papillosum and greenhouse gas fluxes from moss–peat mesocosms. Elevated CO2 levels increased Sphagnum height and dry weight but the magnitude of the response differed among species. The most responsive species, S. fallax, yielded the most biomass compared to S. papillosum and S. capillifolium. Water levels and the CO2 treatment were found to interact, with the highest water level (1 cm below the surface) seeing the largest increase in dry weight under eCO2 compared to ambient (400 ppm) concentrations. Initially, CO2 flux rates were similar between CO2 treatments. After week 9 there was a consistent three-fold increase of the CO2 sink strength under eCO2. At the end of the experiment, S. papillosum and S. fallax were greater sinks of CO2 than S. capillifolium and the − 7 cm water level treatment showed the strongest CO2 sink strength. The mesocosms were net sources of CH4 but the source strength varied with species, specifically S. fallax produced more CH4 than S. papillosum and S. capillifolium. Our findings demonstrate the importance of species selection on the outcomes of peatland restoration with regards to Sphagnum’s growth and GHG exchange.

The first recordings of flora and vegetation in the surroundings of the Moszne lake (Polesie National Park) started from 1960. In 1980s the water conditions in this area changed and affected the organisms that lived there. The aim of this research was to recognize the present state and changes that occurred within flora and vegetation in the course of 18 years (1995–2013). In 2013, at the beginning of June, 34 phytosociological relevés were made on the floating mat that surrounds the Moszne lake in the same locations as they were done in 1995. The obtained data was collated with figures from the literature by comparing the frequency of plant species and plant communities, average plant species coverage and by calculating Sørensen indexes. The results showed that almost the same plant communities were identified in both terms of research. It was found that 35% of the plant species had disappeared after 18 years and that the biggest increase in percentage coverage was noted in case of Phragmites australis and Sphagnum fallax. Those findings show that it is very difficult and sometimes even impossible to reverse the negative influence of water condition change on bogs.

Climate change will influence plant photosynthesis by altering patterns of temperature and precipitation, including their variability and seasonality. Both effects may be important for peatlands as the carbon (C) sink potential of these ecosystems depends on the balance between plant C uptake through photosynthesis and microbial decomposition. Here, we show that the effect of climate warming on Sphagnum community photosynthesis toggles from positive to negative as the peatland goes from rainy to dry periods during summer. More particularly, we show that mechanisms of compensation among the dominant Sphagnum species (Sphagnum fallax and Sphagnum medium) stabilize the average photosynthesis and productivity of the Sphagnum community during summer despite rising temperatures and frequent droughts. While warming had a negligible effect on S. medium photosynthetic capacity (Amax ) during rainy periods, Amax of S. fallax increased by 40%. On the opposite, warming exacerbated the negative effects of droughts on S. fallax with an even sharper decrease of its Amax while S. medium Amax remained unchanged. S. medium showed a remarkable resistance to droughts due to anatomical traits favouring its water holding capacity. Our results show that different phenotypic plasticity among dominant Sphagnum species allow the community to cope with rising temperatures and repeated droughts, maintaining similar photosynthesis and productivity over summer in warmed and control conditions. These results are important because they provide information on how soil water content may modulate the effects of climate warming on Sphagnum productivity in boreal peatlands. It further confirms the transitory nature of warming-induced photosynthesis benefits in boreal systems and highlights the vulnerability of the ecosystem to excess warming and drying.

Sphagnum mosses are keystone components of peatland ecosystems. They facilitate the accumulation of carbon in peat deposits, but climate change is predicted to expose peatland ecosystem to sustained and unprecedented warming leading to a significant release of carbon to the atmosphere. Sphagnum responses to climate change, and their interaction with other components of the ecosystem, will determine the future trajectory of carbon fluxes in peatlands. We measured the growth and productivity of Sphagnum in an ombrotrophic bog in northern Minnesota, where ten 12.8‐m‐diameter plots were exposed to a range of whole‐ecosystem (air and soil) warming treatments (+0 to +9°C) in ambient or elevated (+500 ppm) CO2. The experiment is unique in its spatial and temporal scale, a focus on response surface analysis encompassing the range of elevated temperature predicted to occur this century, and consideration of an effect of co‐occurring CO2 altering the temperature response surface. In the second year of warming, dry matter increment of Sphagnum increased with modest warming to a maximum at 5°C above ambient and decreased with additional warming. Sphagnum cover declined from close to 100% of the ground area to, The responses of Sphagnum to climate change are critical to the future trajectory of peatland ecosystems and their important role in the global carbon cycle. We test three hypotheses related to the response of Sphagnum growth and community composition to experimental warming and CO2 enrichment. The decline of the Sphagnum community with sustained warming that we document can be expected to have many follow‐on consequences to the structure and function of this and similar ecosystems, with significant feedbacks to the global carbon cycle and climate change.

International audience

In this data article, information is provided on sequences of KT-HAK-KUP transporters from green algae and basal land plants. A data set is offered containing sequences corresponding to the chlorophyte algae Chlamydomonas eustigma, Gonium pectorale and Coccomyxa subellipsoidea, the charophyte algae Coleochaete orbicularis and Klebsormidium flaccidum, the bryophyte Sphagnum fallax, the marchantophyte Marchantia polymorpha and the gymnosperm Pinus taeda, which have been not formerly analyzed. In addition, an analysis of similarity scores among representatives of the clusters recognized in photosynthetic green organisms (namely, chlorophyte algae, charophyte algae, basal embryophytes and higher embryophytes) is performed as well as an analysis of membrane topology for them. Fil: Santa Maria, Guillermo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Universidad Nacional de San Martín; Argentina Fil: Oliferuk, Sonia. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina Fil: Moriconi, Jorge Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Universidad Nacional de San Martín; Argentina

Grzesiak, B. & Wolski, G. J. 2015. Bryophilous species of the genus Galerina in peat bogs of Central Poland. — Herzogia 28: 607– 623. Fungi growing on bryophytes or in their close vicinity are referred to as bryophilous fungi. These relationships may be obligate or facultative. Patches of peat bogs are among the most suitable habitats to investigate these relationships. The study aimed to document the co-occurrence of fungi belonging to the genus Galerina and various bryophyte species. The exploration involved six sites representing raised and transitional bogs in Central Poland. The investigation was carried out from 2007 to 2011 on 18 research plots with an area of 10 m². Nine species of fungi were recorded occurring on 21 species of moss. The most fungal species were found on Sphagnum fallax and S. magellanicum.

Sphagnum mosses mediate long-term carbon accumulation in peatlands. Given their functional role as keystone species, it is important to consider their responses to ecological gradients and environmental changes through the production of phenolics. We compared the extent to which Sphagnum phenolic production was dependent on species, microhabitats and season, and how surrounding dwarf shrubs responded to Sphagnum phenolics. We evaluated the phenolic profiles of aqueous extracts of Sphagnum fallax and Sphagnum magellanicum over a 6-month period in two microhabitats (wet lawns versus dry hummocks) in a French peatland. Phenolic profiles of water-soluble extracts were measured by UHPLC-QTOF-MS. Andromeda polifolia mycorrhizal colonization was quantified by assessing the intensity of global root cortex colonization. Phenolic profiles of both Sphagnum mosses were species-, season- and microhabitat- dependant. Sphagnum-derived acids were the phenolics mostly recovered; relative quantities were 2.5-fold higher in S. fallax than in S. magellanicum. Microtopography and vascular plant cover strongly influenced phenolic profiles, especially for minor metabolites present in low abundance. Higher mycorrhizal colonization of A. polifolia was found in lawns as compared to hummocks. Mycorrhizal abundance, in contrast to environmental parameters, was correlated with production of minor phenolics in S. fallax. Our results highlight the close interaction between mycorrhizae such as those colonizing A. polifolia and the release of Sphagnum phenolic metabolites and suggest that Sphagnum-derived acids and minor phenolics play different roles in this interaction. This work provides new insight into the ecological role of Sphagnum phenolics by proposing a strong association with mycorrhizal colonization of shrubs.

Peatlands harbour more than one-third of terrestrial carbon leading to the argument that the bryophytes, as major components of peatland ecosystems, store more organic carbon in soils than any other collective plant taxa. Plants of the genus Sphagnum are important components of peatland ecosystems and are potentially vulnerable to changing climatic conditions. However, the response of Sphagnum to rising temperatures, elevated CO2 and shifts in local hydrology have yet to be fully characterized. In this review, we examine Sphagnum biology and ecology and explore the role of this group of keystone species and its associated microbiome in carbon and nitrogen cycling using literature review and model simulations. Several issues are highlighted including the consequences of a variable environment on plant-microbiome interactions, uncertainty associated with CO2 diffusion resistances and the relationship between fixed N and that partitioned to the photosynthetic apparatus. We note that the Sphagnum fallax genome is currently being sequenced and outline potential applications of population-level genomics and corresponding plant photosynthesis and microbial metabolic modelling techniques. We highlight Sphagnum as a model organism to explore ecosystem response to a changing climate and to define the role that Sphagnum can play at the intersection of physiology, genetics and functional genomics.

This article presents a reconstruction of the development of the ombrotrophic Gązwa peatland based on a high-resolution macrofossil analysis and AMS dating. Successional changes in the plant assemblages dominated by Sphagnum were influenced mainly by climate changes. Local fires occurred in the peatland, but did not have a substantial impact on the Sphagnum succession. The disappearance of the first stage of the ombrotrophic peatland, which was dominated by Sphagnum magellanicum and Sphagnum angustifolium, resulted from a decrease in the water level that was also recorded at a number of sites in Europe in approximately 3750 BC. The development of Sphagnum fuscum/rubellum assemblages in approximately 350 BC corresponds with a climate cooling that resulted from low solar activity. The re-appearance of Sphagnum magellanicum in approximately AD 1650 corresponds with the Maunder Minimum of the Little Ice Age. The recent dominance of Sphagnum fallax is a result of the drainage of the peatland and of ch...

Bryophytes dominate northern peatlands. Obtaining reliable measurements of moss-growth and how it may be affected by global changes are therefore important. Several methods have been used to measure moss-growth but it is unclear how comparable they are in different conditions and this uncertainty undermines comparisons among studies. In a field experiment we measured the growth and production of Sphagnum fallax (Sphagnum) and Polytrichum strictum (Polytrichum) using two handling methods, using cut and uncut plants, and three growth-variables, height-growth, length-growth, and mass-growth. We aimed “benchmarking” a combination of six methodological options against exactly the same set of factorial experiments: atmospheric CO2 enrichment and N addition. The two handling methods produced partly different results: in half of the cases, one method revealed a significant treatment effect but the other one did not: significant negative effects on growth were only observed on uncut plants for elevated CO2 and on cut plants for N addition. Furthermore, the correspondence between measurements made with various growth-variables depended on the species and, to a lesser extent, treatments. Sphagnum and Polytrichum growth was inhibited under elevated CO2, and correlated to higher ammonium values. Sphagnum was however less affected than Polytrichum and the height difference between the two species decreased. N addition reduced the P/N ratio and probably induced P-limiting conditions. Sphagnum growth was more inhibited than Polytrichum and the height difference between the two species increased. Our data show that such a problem indeed exists between the cut and uncut handling methods. Not only do the results differ in absolute terms by as much as 82% but also do their comparisons and interpretations depend on the handling method—and thus the interpretation would be biased—in half of the cases. These results call for caution when comparing factorial studies based on different handling methods.

Sphagnum mosses serve as a unique habitat for microorganisms, which play an important role both for the host plants and the peatland ecosystems. The aim of the present study was to isolate endophytic bacteria from the tissues of Sphagnum mosses and to screen them for strains promising for further application in agricultural microbiology. About 50 samples of Sphagnum fallax (H. Klinggr.) H. Klinggr. and Sphagnum magellanicum Brid. were collected in the Austrian Alps and the Lenindgrad Region of Russia in 2009–2010. Endophytic bacteria were detected inside the moss plants using fluorescent in situ hybridization (FISH) followed by confocal laser scanning microscopy (CLSM). Altogether, 283 isolates were obtained by cultivation on the nutrient media. Examination of the isolates for the antagonistic activity revealed that more than 50% of them could suppress the growth of phytopathogenic and toxigenic fungi. More than 30% of isolates showed some antagonistic activity against microbial phytopathogens. The isolated strains could colonize crops and promote their growth. Molecular-genetic identification coupled with physiological/biochemical characterization showed that the dominant endophytic groups belonged to the genera Burkholderia, Pseudomonas, Flavobacterium, Serratia and Collimonas. The isolated endophytes were shown to be promising objects for the development of effective growth-promoting and protective microbiological preparations to be used in agriculture.

In peatland ecosystems, plant communities mediate a globally significant carbon store. The effects of global environmental change on plant assemblages are expected to be a factor in determining how ecosystem functions such as carbon uptake will respond. Using vegetation data from 56 Sphagnum-dominated peat bogs across Europe, we show that in these ecosystems plant species aggregate into two major clusters that are each defined by shared response to environmental conditions. Across environmental gradients, we find significant taxonomic turnover in both clusters. However, functional identity and functional redundancy of the community as a whole remain unchanged. This strongly suggests that in peat bogs, species turnover across environmental gradients is restricted to functionally similar species. Our results demonstrate that plant taxonomic and functional turnover are decoupled, which may allow these peat bogs to maintain ecosystem functioning when subject to future environmental change.

It is well accepted that the shape of the dispersal kernel, especially its tail, has a substantial effect on the genetic structure of species. Theory predicts that dispersal by fat-tailed kernels reshuffles genetic material, and thus, preserves genetic diversity during colonization. Moreover, if efficient long-distance dispersal is coupled with random colonization, an inverse isolation effect is predicted to develop in which increasing genetic diversity per colonizer is expected with increasing distance from a genetically variable source. By contrast, increasing isolation leads to decreasing genetic diversity when dispersal is via thin-tailed kernels. Here, we use a well-established model group for dispersal biology (peat mosses: genus Sphagnum) with a fat-tailed dispersal kernel, and the natural laboratory of the Stockholm archipelago to study the validity of the inverse isolation hypothesis in spore-dispersed plants in island colonization. Population genetic structure of three species (Sphagnum fallax, Sphagnum fimbriatum and Sphagnum palustre) with contrasting life histories and ploidy levels were investigated on a set of islands using microsatellites. Our data show (ϕ'(st), amova, IBD) that dispersal of the two most abundant species can be well approximated by a random colonization model. We find that genetic diversity per colonizer on islands increases with distance from the mainland for S. fallax and S. fimbriatum. By contrast, S. palustre deviates from this pattern, owing to its restricted distribution in the region, affecting its source pool strength. Therefore, the inverse isolation effect appears to hold in natural populations of peat mosses and, likely, in other organisms with small diaspores.

International audience; Population dynamics and feeding habits of the testate amoebae Nebela tincta and Hyalosphenia papilio were studied along a short "fen" to "bog" gradient in a Sphagnum-dominated mire (Jura, France). Samples were collected in living "top segments" (0-3cm) and early declining "bottom segments" (3-6cm) of Sphagnum fallax peat. Observations of digestive vacuole content and stable isotope analyses ((13)C and (15)N) were used to establish the feeding behavior of both testate amoeba species. Owing to their vertical distribution, the feeding habit of H. papilio was described from top segments, and that of N. tincta from bottom segments. Among identified food sources, those most frequently ingested by N. tincta were spores and mycelia of fungi (55%), microalgae (25%) and cyanobacteria (8.5%). For H. papilio, the most frequently ingested prey were ciliates (55%) and microalgae (35%). Nonmetric Multidimensional Scaling analysis clearly demonstrated that the two species did not have the same feeding habit along the "fen-bog" gradient, and furthermore that a significant spatial split exists in the feeding behavior of H. papilio. Additionally, isotope analyses suggested that H. papilio and N. tincta did not have the same trophic position in the microbial food web, probably resulting from their different feeding strategies.

Summary 1. Bogs are nutrient-poor peatland ecosystems that are sensitive to nitrogen (N) deposition. Production of peat mosses (i.e. the peat-forming genus Sphagnum) is known to decrease under elevated N deposition, but the causal mechanisms are poorly understood. 2. It is predicted that increased N deposition will cause changes in Sphagnum species composition, with fast-growing species benefiting from increased N availability in contrast to slow-growing species. Knowledge of species-specific responses to N availability can help us to understand interspecific competitive relationships. 3. We investigated the direct effects of N application on plant physiology in three Sphagnum species by exposing shoots to a range of N doses (corresponding to depositions of 0–5·6 g m−2 year−1), over 5 months, in a greenhouse experiment. The species investigated included one that grows high above the water-table (Sphagnum fuscum) and two that grow lower down (Sphagnum balticum and Sphagnum fallax). S. fuscum and S. balticum originate from ombrotrophic and S. fallax from minerotrophic environments. To estimate N responses, we measured the performance and light-capture kinetics of the photosynthetic apparatus (maximum photosynthetic rate and Fv/Fm), biomass production, shoot formation, and N and phosphorus (P) concentrations in the tissue. 4. Tissue nitrogen concentration generally increased with N application rate, and photosynthetic rate increased with N concentration, although S. balticum exhibited a unimodal response. With respect to production, a negative response to N application rate was found in S. fallax and S. fuscum (weak), while production in S. balticum was unrelated to application rate. S. fallax was the fastest-growing species, producing two to three times more biomass per shoot compared with the other species. 5. The mismatch between photosynthetic capacity and production could partly be explained by an increased N : P ratio following N application. Phosphorus limitation may not negatively affect photosynthetic capacity, but may hamper production. 6. The fast-growing species S. fallax is considered to benefit from increased N deposition, but we found a negative physiological response, suggesting stoichiometric constraints. Thus, we conclude that responses to N deposition cannot be predicted in a simple way from physiological traits related to growth rate without considering local environmental factors.

The purpose of this study was to assess the application of several bioindication methods for the monitoring of environmental pollution from Pb and Cd. The study area centered on the town of Olkusz, Poland, which is one of the oldest centers for the metallurgical industry in Europe. The assessment of environmental pollution due to metals was performed using four frequently used bioindication methods: moss-bag (Sphagnum fallax), determination of metal accumulation in Pleurozium schreberi, silver birch foliage, and Scots pine needles. The region of Olkusz, and especially the area surrounding the mining and metallurgical Bolesław complex, was extremely contaminated with Pb and Cd. The results of the investigations are presented as contamination deposition maps. Despite the application of various methods and the resulting diversity of the specific exposure periods for different biomonitors, the spatial distribution of contamination shown on the maps was similar, as confirmed by the statistical analysis of the results.

Extracellular phenoloxidase enzymes play an important role in the stability of soil carbon storage by contributing to the cycling of complex recalcitrant phenolic compounds. Climate warming could affect peatland functioning through an alteration of polyphenol/phenoloxidase interplay, which could lead them to becoming weaker sinks of carbon. Here, we assessed the seasonal variability of total phenolics and phenoloxidases subjected to 2-3 degrees C increase in air temperature using open-top chambers. The measurements were performed along a narrow fen-bog ecological gradient over one growing season. Climate warming had a weak effect on phenoloxidases, but reduced phenolics in both fen and bog areas. Multivariate analyses revealed a split between the areas and also showed that climate warming exacerbated the seasonal variability of polyphenols, culminating in a destabilization of the carbon cycle. A negative relationship between polyphenols and phenoloxidases was recorded in controls and climate treatments suggesting an inhibitory effect of phenolics on phenoloxidases. Any significant decrease of phenolics through repeatedly elevated temperature would greatly impact the ecosystem functioning and carbon cycle through an alteration of the interaction of polyphenols with microbial communities and the production of extracellular enzymes. Our climate treatments did not have the same impact along the fen-bog gradient and suggested that not all the peatland habitats would respond similarly to climate forcing.

International audience; Microbial communities living in Sphagnum are known to constitute early indicators of ecosystem disturbances, but little is known about their response ( including their trophic relationships) to climate change. A microcosm experiment was designed to test the effects of a temperature gradient ( 15, 20, and 25 degrees C) on microbial communities including different trophic groups ( primary producers, decomposers, and unicellular predators) in Sphagnum segments (0-3 cm and 3-6 cm of the capitulum). Relationships between microbial communities and abiotic factors ( pH, conductivity, temperature, and polyphenols) were also studied. The density and the biomass of testate amoebae in Sphagnum upper segments increased and their community structure changed in heated treatments. The biomass of testate amoebae was linked to the biomass of bacteria and to the total biomass of other groups added and, thus, suggests that indirect effects on the food web structure occurred. Redundancy analysis revealed that microbial assemblages differed strongly in Sphagnum upper segments along a temperature gradient in relation to abiotic factors. The sensitivity of these assemblages made them interesting indicators of climate change. Phenolic compounds represented an important explicative factor in microbial assemblages and outlined the potential direct and ( or) indirect effects of phenolics on microbial communities.

Two experiments were conducted for developing restoration techniques for pool margin communities in cutover peatlands. We first aimed to measure the regeneration potential of a typical edge pool liverwort, Cladopodiella fluitans (Nees) H. Buch. We introduced C. fluitans in floating baskets in a restored peatland. We tested three fragment sizes (patches of 2 cm 2 , stretched patches and shredded fine fragments of 0.1–1 mm), two introduction densities (ratio between surface of collected areas and surface of restored areas of 1:5 and 1:10) as well as the effect of a straw mulch. After two years, the percentage covers of C. fluitans were five times larger in experimental units protected with straw than in those without protection. Yet, the fragment sizes and the densities tested had no effect on the regeneration of the liverwort. The second experiment aimed to test a moss layer transfer approach to restore plant diversity around pool margins. We tested four communities, dominated by (1) Sphagnum cuspidatum Hoffman, (2) Sphagnum fallax (H. Klinggraff) H. Klinggraff, (3) Sphagnum papillosum Linberg as well as (4) a mixed community composed of equal quantities of C. fluitans , S. cuspidatum and S. papillosum . We introduced plant material in two density ratios (1:5 and 1:10). Sphagnum mosses did colonize pool margins, and showed even more than 60% cover for some treatments after three growing seasons, but the recovery of the introduced vascular plants remained below 5% for most species. The establishment of pool vascular species thus seems to be more intricate than for bryophytes and specific introduction techniques might be needed.

Changes in the vegetation of "Wrzosiec" mire in 1991-2009 (Western Pomerania) Changes in the vegetation of a mire developing in forest lake hinterland in 1991-2009 are analysed and documented three times by phytosociological method. Within peat bog "islands", situated in the southern part of the lake, the most visible change is the development of a sparse pine-stand and thick shrubs of Salix species, Frangula alnus as well as increase in the participation of Molinia caerulea and some species of Scheuzerio-Caricetea class (Calamagrostis neglecta, Carex lasiocarpa and Sphagnum fallax). Vegetation of the lag zone shows fluctuating changes in the composition of plant communities depending on the water level that periodically changes. In the north-eastern part of the lake, a consistent slow process of terrestrialization was recognised.

Compound-specific isotope measurements of organic compounds are increasingly important in palaeoclimate reconstruction. Searching for more accurate peat-based palaeoenvironmental proxies, compound-specific fractionation of stable C, H and O isotopes of organic compounds synthesized by Sphagnum were determined in a greenhouse study. Three Sphagnum species were grown under controlled climate conditions. Stable isotope ratios of cellulose, bulk organic matter (OM) and C 21 –C 25 n -alkanes were measured to explore whether fractionation in Sphagnum is species-specific, as a result of either environmental conditions or genetic variation. The oxygen isotopic composition (δ 18 O) of cellulose was equal for all species and all treatments. The hydrogen isotopic composition (δD) of the n -alkanes displayed an unexpected variation among the species, with values between −154‰ for Sphagnum rubellum and −184‰ for Sphagnum fallax for the C 23 n -alkane, irrespective of groundwater level. The stable carbon isotopic composition (δ 13 C) of the latter also showed a species-specific pattern. The pattern was similar for the carbon isotope fractionation of bulk OM, although the C 23 n -alkane was >10‰ more depleted than the bulk OM. The variation in H fractionation may originate in the lipid biosynthesis, whereas C fractionation is also related to humidity conditions. Our findings clearly emphasize the importance of species identification in palaeoclimate studies based on stable isotopes from peat cores.

The genus Sphagnum is known for its morphological variable species, showing plastic responses along environmental gradients (Stenøien et al. 1997). Consequently, species delimitation based on morphological characters is not always straight forward. However, molecular analysis have in some cases pointed to differentiated entities within morphologically recognised taxa, e.g. Sphagnum fuscum (Schimper 1871:63) Klinggräff (1872:4) and Sphagnum magellanicum Bridel (1798:24) (Kyrkjeeide et al. 2015, Yousefi et al. 2017). In other cases, molecular markers have not resolved closely related taxa. A study based on isoenzymes could, for instance, not differentiate Sphagnum viride Flatberg (1988:9) from Sphagnum cuspidatum Ehrh. ex Hoffmann (1796:22) (Hanssen et al. 2000). Moreover, a study based on isoenzymes and RAPD could not differentiate Sphagnum isoviitae Flatberg (1992:2) and Sphagnum brevifolium (Lindb. ex Braithwaite (1878:84)) Röll (1889:340) from Sphagnum fallax (Klinggräff 1872:7) Klinggräff (1880: 128) (Såstad et al. 1999). Hence, the treatment of these taxa at the species level may be questioned. The material used in the studies was limited, and the use of more modern molecular markers might lead to other conclusions. Recognition of the taxa at variety level seems to be a reasonable solution, given our current knowledge. We therefore propose that S. viride, S. isoviitae and S. brevifolium be treated at the variety level while we await more comprehensive genetic studies, which may provide conclusive evidence concerning the status of these taxa.