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Gabriele Berg - One of the best experts on this subject based on the ideXlab platform.
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Sphagnum mosses harbour highly specific bacterial diversity during their whole lifecycle
The ISME Journal, 2012Co-Authors: Anastasia Bragina, Christian Berg, Massimiliano Cardinale, A V Shcherbakov, V K Chebotar, Gabriele BergAbstract:Knowledge about Sphagnum-associated microbial communities, their structure and their origin is important to understand and maintain climate-relevant Sphagnum-dominated bog ecosystems. We studied bacterial communities of two cosmopolitan Sphagnum species, which are well adapted to different abiotic parameters (Sphagnum magellanicum, which are strongly acidic and ombrotrophic, and Sphagnum fallax, which are weakly acidic and mesotrophic), in three Alpine bogs in Austria by a multifaceted approach. Great differences between bacterial fingerprints of both Sphagna were found independently from the site. This remarkable specificity was confirmed by a cloning and a deep sequencing approach. Besides the common Alphaproteobacteria, we found a discriminative spectrum of bacteria; although Gammaproteobacteria dominated S. magellanicum, S. fallax was mainly colonised by Verrucomicrobia and Planctomycetes. Using this information for fluorescent in situ hybridisation analyses, corresponding colonisation patterns for Alphaproteobacteria and Planctomycetes were detected. Bacterial colonies were found in high abundances inside the dead big hyalocytes, but they were always connected with the living chlorocytes. Using multivariate statistical analysis, the abiotic factors nutrient richness and pH were identified to modulate the composition of Sphagnum-specific bacterial communities. Interestingly, we found that the immense bacterial diversity was transferred via the sporophyte to the gametophyte, which can explain the high specificity of Sphagnum-associated bacteria over long distances. In contrast to higher plants, which acquire their bacteria mainly from the environment, mosses as the phylogenetically oldest land plants maintain their bacterial diversity within the whole lifecycle.
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similar diversity of alphaproteobacteria and nitrogenase gene amplicons on two related Sphagnum mosses
Frontiers in Microbiology, 2012Co-Authors: Anastasia Bragina, Vladimir Chobot, Franz Hadacek, Christian Berg, Stefanie Maier, Henry Muller, Gabriele BergAbstract:Sphagnum mosses represent a main component in ombrotrophic wetlands. They harbor a specific and diverse microbial community with essential functions for the host. To understand extend and degree of host specificity, Sphagnum fallax and S. angustifolium, two phylogenetically closely related species, which show distinct habitat preference with respect to the nutrient level, were analyzed by a multifaceted approach. Microbial fingerprints obtained by PCR-SSCP (single-strand conformation polymorphism) using universal, group-specific and functional primers were highly similar. Similarity was confirmed for colonization patterns obtained by fluorescence in situ hybridization (FISH) coupled with confocal laser scanning microscopy (CLSM): Alphaproteobacteria were the main colonizers inside the hyaline cells of Sphagnum leaves. A deeper survey of Alphaproteobacteria by 16S rRNA gene amplicon sequencing reveals a high diversity with Acidocella, Acidisphaera, Rhodopila and Phenylobacterium as major genera for both mosses. Pathogen defense and nitrogen fixation are important functions of Sphagnum-associated bacteria, which are fulfilled by microbial communities of both Sphagna in a similar way. NifH libraries of Sphagnum-associated microbial communities were characterized by high diversity and abundance of Alphaproteobacteria but contained also diverse amplicons of other taxa, e.g. Cyanobacteria, Geobacter and Spirochaeta. Statistically significant differences between the microbial communities of both Sphagnum species could not be discovered in any of the experimental approach. Our results show that the same close relationship, which exists between the physical, morphological and chemical characteristics of Sphagnum mosses and the ecology and function of bog ecosystems, also connects moss plantlets with their associated bacterial communities.
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Investigations of the structure and function of bacterial communities associated with Sphagnum mosses
Environmental microbiology, 2007Co-Authors: Katja Opelt, Vladimir Chobot, Franz Hadacek, Susan Schönmann, Leo Eberl, Gabriele BergAbstract:High acidity, low temperature and extremely low concentration of nutrients form Sphagnum bogs into extreme habitats for organisms. Little is known about the bacteria associated with living Sphagnum plantlets, especially about their function for the host. Therefore, we analysed the endo- and ectophytic bacterial populations associated with two widely distributed Sphagnum species, Sphagnum magellanicum and Sphagnum fallax, by a multiphasic approach. The screening of 1222 isolates for antagonistic activity resulted in 326 active isolates. The bacterial communities harboured a high proportion of antifungal (26%) but a low proportion of antibacterial isolates (0.4%). Members of the genus Burkholderia (38%) were found to be the most dominant group of antagonistic bacteria. The finding that a large proportion (89%) of the antagonistic bacteria produced antifungal compounds may provide an explanation for the well-known antimicrobial activity of certain Sphagnum species. The secondary metabolites of the Sphagnum species themselves were analysed by HPLC-PDA. The different spectra of detected compounds may not only explain the antifungal activity but also the species specificity of the microbial communities. The latter was analysed using cultivation-independent single-stranded conformation polymorphism (SSCP) analysis. Using Burkholderia-specific primers we found a high diversity of Burkholderia isolates in the endophytic and ectophytic habitats of Sphagnum. Furthermore, a high diversity of nitrogen-fixing bacteria was detected by using nifH-specific primers, especially inside Sphagnum mosses. In conclusion, this study provides evidence that both Sphagnum species were colonized by characteristic bacterial populations, which appear to be important for pathogen defence and nitrogen fixation.
Fatima Laggoun-défarge - One of the best experts on this subject based on the ideXlab platform.
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CO 2 and CH 4 budgets and global warming potential modifications in Sphagnum -dominated peat mesocosms invaded by Molinia caerulea
Biogeosciences, 2019Co-Authors: Fabien Leroy, Sébastien Gogo, Christophe Guimbaud, Léonard Bernard-jannin, Xiaole Yin, Guillaume Belot, Wang Shuguang, Fatima Laggoun-défargeAbstract:Plant communities play a key role in regulating greenhouse gas (GHG) emissions in peatland ecosystems and therefore in their ability to act as carbon (C) sinks. However , in response to global change, a shift from Sphagnum-dominated to vascular-plant-dominated peatlands may occur , with a potential alteration in their C-sink function. To investigate how the main GHG fluxes (CO 2 and CH 4) are affected by a plant community change (shift from dominance of Sphagnum mosses to vascular plants, i.e., Molinia caerulea), a mesocosm experiment was set up. Gross primary production (GPP), ecosystem respiration (ER) and CH 4 emission models were used to estimate the annual C balance and global warming potential under both vegetation covers. While the ER and CH 4 emission models estimated an output of, respectively, 376 ± 108 and 7 ± 4 g C m −2 yr −1 in Sphagnum mesocosms, this reached 1018 ± 362 and 33 ± 8 g C m −2 yr −1 in mesocosms with Sphagnum rubellum and Molinia caerulea. Annual modeled GPP was estimated at −414±122 and −1273±482 g C m −2 yr −1 in Sphagnum and Sphagnum + Molinia plots, respectively, leading to an annual CO 2 and CH 4 budget of −30 g C m −2 yr −1 in Sphagnum plots and of −223 g C m −2 yr −1 in Sphagnum + Molinia ones (i.e., a C sink). Even if CH 4 emissions accounted for a small part of the gaseous C efflux (ca. 3 %), their global warming potential value makes both plant communities have a climate warming effect. The shift of vegetation from Sphagnum mosses to Molinia caerulea seems beneficial for C sequestra-tion at a gaseous level. However, roots and litter of Molinia caerulea could provide substrates for C emissions that were not taken into account in the short measurement period studied here.
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CO2 and CH4 budgets and global warming potential modifications in Sphagnum-dominated peat mesocosms invaded by Molinia caerulea
Biogeosciences Discussions, 2017Co-Authors: Fabien Leroy, Sébastien Gogo, Christophe Guimbaud, Léonard Bernard-jannin, Xiaole Yin, Guillaume Belot, Wang Shuguang, Fatima Laggoun-défargeAbstract:Plant communities play a key role in regulating greenhouse gas (GHG) emissions in peatland ecosystems and therefore in their ability to act as carbon (C) sinks. However, in response to global change, a shift from Sphagnum to vascular plant-dominated peatlands may occur, with a potential alteration in their C-sink function. To investigate how the main GHG fluxes (CO2 and CH4) are affected by a plant community change (shift from dominance of Sphagnum mosses to 15 vascular plants, i.e. Molinia caerulea), a mesocosm experiment was set up. Gross primary production (GPP), ecosystem respiration (ER) and CH4 emission models were used to estimate the annual C balance and global warming potential under both vegetation covers. While the ER and CH4 emission models estimated an output of, respectively, 376 and 7 gC m-2 y-1 in Sphagnum mesocosms, this reached 1018 and 33 gC m-2 y-1 in mesocosms with Sphagnum rubellum and Molinia caerulea. Annual modelled GPP was estimated at-414 and-1273 gC m-2 y-1 in Sphagnum and Sphagnum + Molinia plots, respectively, 20 leading to an annual CO2 and CH4 budget of – 30 gC m-2 y-1 in Sphagnum plots and of-223 gC m-2 y-1 in Sphagnum + Molinia ones (i.e., a C-sink). Even if, CH4 emissions accounted for a small part of the gaseous C efflux (ca. 3%), their global warming potential value makes both plant communities have a climate warming effect. The shift of vegetation from Sphagnum mosses to Molinia caerulea seems beneficial for C sequestration at a gaseous level. However, roots and litters of Molinia caerulea could provide substrates for C emissions that were not taken into account in the short measurement period 25 studied here.
Hans Joosten - One of the best experts on this subject based on the ideXlab platform.
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Seven years of spider community succession in a Sphagnum farm
The Journal of Arachnology, 2020Co-Authors: Christoph Muster, Matthias Krebs, Hans JoostenAbstract:Sphagnum farming is paludiculture aiming to produce Sphagnum biomass as a sustainable alternative to peat in horticultural growing media. Here we focus on the habitat value of artificial Sphagnum farming sites for peatland species. We report results from seven years of biodiversity monitoring (2011–2018) in a 14 ha Sphagnum farm in north western Germany, using spiders and harvestmen as indicator groups for succession of invertebrate communities. Species richness and abundance more than doubled in the first two years of Sphagnum growth, but remained rather constant since then. Peatland generalists rapidly colonized the site and constitute some 30%–40% of activity dominance since the second year. Stenotopic peatland spiders arrived later, but their abundance proportion increased significantly from 2014 to 2017. Nevertheless, the spider communities remain distinct from (semi-)natural reference sites. Highly characteristic species of pristine bogs are still lacking. We conclude that a novel community has assembled that bears only moderate resemblance to natural peatlands. Persisting high annual turnover rates in terms of species composition and dominance structure (both > 30%) corroborate high levels of ongoing dynamics and the significance of stochastic processes. The long-term trajectory of community succession in the Sphagnum farm remains vague.
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Sphagnum farming: the promised land for peat bog species?
Biodiversity and Conservation, 2015Co-Authors: Christoph Muster, Matthias Krebs, Greta Gaudig, Hans JoostenAbstract:Sphagnum farming is a promising approach towards sustainability in growing media production for horticulture. In this study we focus on the additional value of Sphagnum farming sites as a surrogate habitat for threatened peat bog fauna. The highly diverse arthropod groups of spiders and harvestmen were used as bioindicators to track changes in species assemblages over the first 3 years of Sphagnum farming on a site in northwestern Germany. The results were compared with simultaneously studied reference habitats of nearby bog grasslands and degraded peat bog remnants. Spider communities changed rapidly from assemblages dominated by disturbance specialists (pioneer species) in the year of artificial Sphagnum establishment to diverse assemblages with large proportions of peatland generalists in the following years. Conservation value based on rarity, Red List status, disturbance tolerance and peatland association of individual species was in the later stage of Sphagnum farming as high as in the seminatural reference sites. Species quality index as derived from rarity scores was particularly high in the first year of succession due to the occurrence of some rare disturbance specialists. Despite the fact that each succession stage has its own conservation value, we advocate long rotation cycles in Sphagnum farming to allow establishment of slowly colonizing peatland specialists. We generally recommend the establishment of Sphagnum farms on degraded peatland, as creation of this artificial habitat promotes landscape and species diversity and provides refuges for endangered species of peatland and ephemeral habitats.
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Sphagnum farming in Germany – a review of progress
Mires and Peat, 2014Co-Authors: Greta Gaudig, Matthias Krebs, F. Fengler, Anja Prager, J. Schulz, Sabine Wichmann, Hans JoostenAbstract:In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp.) is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’) in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural growing media. Sphagnum farming is, furthermore, a climate-friendly and sustainable land use option for abandoned cutover bogs and degraded bog grassland.
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Sphagnum farming in germany a review of progress
Mires and Peat, 2014Co-Authors: Greta Gaudig, Matthias Krebs, F. Fengler, Anja Prager, J. Schulz, Sabine Wichmann, Hans JoostenAbstract:In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp.) is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’) in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural growing media. Sphagnum farming is, furthermore, a climate-friendly and sustainable land use option for abandoned cutover bogs and degraded bog grassland.
Angela V Gallegosala - One of the best experts on this subject based on the ideXlab platform.
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global scale pattern of peatland Sphagnum growth driven by photosynthetically active radiation and growing season length
Biogeosciences, 2012Co-Authors: Julie Loisel, Angela V GallegosalaAbstract:Abstract. High-latitude peatlands contain about one third of the world's soil organic carbon, most of which is derived from partly decomposed Sphagnum (peat moss) plants. We conducted a meta-analysis based on a global data set of Sphagnum growth measurements collected from published literature to investigate the effects of bioclimatic variables on Sphagnum growth. Analysis of variance and general linear models were used to relate Sphagnum magellanicum and S. fuscum growth rates to photosynthetically active radiation integrated over the growing season (PAR0) and a moisture index. We found that PAR0 was the main predictor of Sphagnum growth for the global data set, and effective moisture was only correlated with moss growth at continental sites. The strong correlation between Sphagnum growth and PAR0 suggests the existence of a global pattern of growth, with slow rates under cool climate and short growing seasons, highlighting the important role of growing season length in explaining peatland biomass production. Large-scale patterns of cloudiness during the growing season might also limit moss growth. Although considerable uncertainty remains over the carbon balance of peatlands under a changing climate, our results suggest that increasing PAR0 as a result of global warming and lengthening growing seasons, without major change in cloudiness, could promote Sphagnum growth. Assuming that production and decomposition have the same sensitivity to temperature, this enhanced growth could lead to greater peat-carbon sequestration, inducing a negative feedback to climate change.
Greta Gaudig - One of the best experts on this subject based on the ideXlab platform.
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Temporal dynamics in the taxonomic and functional profile of the Sphagnum-associated fungi (mycobiomes) in a Sphagnum farming field site in Northwestern Germany.
FEMS microbiology ecology, 2020Co-Authors: Mathilde Borg Dahl, Matthias Krebs, Martin Unterseher, Tim Urich, Greta GaudigAbstract:The drainage of peatlands for their agricultural use leads to huge emissions of greenhouse gases. One sustainable alternative is the cultivation of peat mosses after rewetting ('Sphagnum farming'). Environmental parameters of such artificial systems may differ from those of natural Sphagnum ecosystems which host a rich fungal community. We studied the fungal community at a 4 ha Sphagnum farming field site in Northwestern Germany and compared it with that of natural Sphagnum ecosystems. Additionally, we asked if any fungi occur with potentially negative consequences for the commercial production and/or use of Sphagnum biomass. Samples were collected every 3 months within 1 year. High-throughput sequencing of the fungal ITS2 barcode was used to obtain a comprehensive community profile of the fungi. The dominant taxa in the fungal community of the Sphagnum farming field site were all commonly reported from natural Sphagnum ecosystems. While the taxonomic composition showed clear differences between seasons, a stable functional community profile was identified across seasons. Additionally, nutrient supply seems to affect composition of fungal community. Despite a rather high abundance of bryophyte parasites, and the occurrence of both Sphagnum-species-specific and general plant pathogens, their impact on the productivity and usage of Sphagnum biomass as raw material for growing media was considered to be low.
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Sphagnum farming: the promised land for peat bog species?
Biodiversity and Conservation, 2015Co-Authors: Christoph Muster, Matthias Krebs, Greta Gaudig, Hans JoostenAbstract:Sphagnum farming is a promising approach towards sustainability in growing media production for horticulture. In this study we focus on the additional value of Sphagnum farming sites as a surrogate habitat for threatened peat bog fauna. The highly diverse arthropod groups of spiders and harvestmen were used as bioindicators to track changes in species assemblages over the first 3 years of Sphagnum farming on a site in northwestern Germany. The results were compared with simultaneously studied reference habitats of nearby bog grasslands and degraded peat bog remnants. Spider communities changed rapidly from assemblages dominated by disturbance specialists (pioneer species) in the year of artificial Sphagnum establishment to diverse assemblages with large proportions of peatland generalists in the following years. Conservation value based on rarity, Red List status, disturbance tolerance and peatland association of individual species was in the later stage of Sphagnum farming as high as in the seminatural reference sites. Species quality index as derived from rarity scores was particularly high in the first year of succession due to the occurrence of some rare disturbance specialists. Despite the fact that each succession stage has its own conservation value, we advocate long rotation cycles in Sphagnum farming to allow establishment of slowly colonizing peatland specialists. We generally recommend the establishment of Sphagnum farms on degraded peatland, as creation of this artificial habitat promotes landscape and species diversity and provides refuges for endangered species of peatland and ephemeral habitats.
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Sphagnum farming in Germany – a review of progress
Mires and Peat, 2014Co-Authors: Greta Gaudig, Matthias Krebs, F. Fengler, Anja Prager, J. Schulz, Sabine Wichmann, Hans JoostenAbstract:In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp.) is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’) in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural growing media. Sphagnum farming is, furthermore, a climate-friendly and sustainable land use option for abandoned cutover bogs and degraded bog grassland.
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Sphagnum farming in germany a review of progress
Mires and Peat, 2014Co-Authors: Greta Gaudig, Matthias Krebs, F. Fengler, Anja Prager, J. Schulz, Sabine Wichmann, Hans JoostenAbstract:In ombrotrophic, nutrient-poor peatlands, the cultivation of peatmoss (Sphagnum spp.) is a promising paludiculture option. Since 2001 we have been studying peatmoss cultivation (‘Sphagnum farming’) in greenhouse and field experiments, paying special attention to propagation, propagule storage, establishment, productivity and regeneration. Our studies show that Sphagnum farming in Germany may provide a sustainable high-quality alternative to fossil white peat as a raw material for horticultural growing media. Sphagnum farming is, furthermore, a climate-friendly and sustainable land use option for abandoned cutover bogs and degraded bog grassland.
