| 1. |
- Baldaque-Silva, Francisco, et al.
(författare)
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Endoscopic assessment and grading of Barrett's esophagus using magnification endoscopy and narrow band imaging: Impact of structured learning and experience on the accuracy of the Amsterdam classification system
- 2013
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 48:2, s. 160-167
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Several classification systems have been launched to characterize Barrett's esophagus (BE) mucosa using magnification endoscopy with narrow band imaging (ME-NBI). The good accuracy and interobserver agreement described in the early reports were not reproduced subsequently. Recently, we reported somewhat higher accuracy of the classification developed by the Amsterdam group. The critical question then formulated was whether a structured learning program and the level of experience would affect the clinical usefulness of this classification. Material & methods: Two hundred and nine videos were prospectively captured from patients with BE using ME-NBI. From these, 70 were randomly selected and evaluated by six endoscopists with different levels of expertise, using a dedicated software application. First, an educational set was studied. Thereafter, the 70 test videos were evaluated. After classification of each video, the respective histological feedback was automatically given. Results. Within the learning process, there was a decrease in the time needed for evaluation and an increase in the certainty of prediction. The accuracy did not increase with the learning process. The sensitivity for detection of intestinal metaplasia ranged between 39% and 57%, and for neoplasia between 62% and 90%, irrespective of assessor's expertise. The kappa coefficient for the interobserver agreement ranged from 0.25 to 0.30 for intestinal metaplasia, and from 0.39 to 0.48 for neoplasia. Conclusion: Using a dedicated learning program, the ME-NBI Amsterdam classification system is suboptimal in terms of accuracy and inter- and intraobserver agreements. These results reiterate the questionable utility of corresponding classification system in clinical routine practice.
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| 2. |
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| 3. |
- Boeddinghaus, Runa S., et al.
(författare)
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The mineralosphere—interactive zone of microbial colonization and carbon use in grassland soils
- 2021
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Ingår i: Biology and Fertility of Soils. - : Springer Science and Business Media LLC. - 0178-2762 .- 1432-0789. ; 57:5, s. 587-601
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Tidskriftsartikel (refereegranskat)abstract
- To improve our understanding of early microbial colonization of pristine minerals and their group-specific C utilization, we exposed minerals (illite/goethite/quartz) amended with artificial root exudates (ARE, glucose, and citric acid) in grassland soils for a period of 24 weeks. FTIR spectra indicated that mineral-associated ARE were used within the first 2 weeks of exposure and were replaced by other carbohydrates derived from living or dead cells as well as soil-borne C sources transported into the mineralosphere after heavy rain events. Fungi and Gram-positive bacteria incorporated ARE-derived C more rapidly than Gram-negative bacteria. Gram-negative bacteria presumably profited indirectly from the ARE by cross-feeding on mineral-associated necromass of fungi and Gram-positive bacteria. The Gram-negative bacterial phyla Verrucomicrobia, Planctomycetes, Gemmatimonadetes, Armatimonadetes, and Chloroflexi showed a positive correlation with Gram-negative PLFA abundances. After 24 weeks of exposure in the grassland soils, abundances of soil microorganisms in the mineralosphere reached only 3.1% of the population density in soil. In conclusion, both bacteria and fungi slowly colonize new surfaces such as pristine minerals, but quickly assimilate artificial root exudates, creating an active microbial community in the mineralosphere.
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| 4. |
- Cardoso-Moreira, Margarida, et al.
(författare)
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Gene expression across mammalian organ development
- 2019
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Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 571:7766, s. 505-
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of gene expression in mammalian organ development remains largely uncharacterized. Here we report the transcriptomes of seven organs (cerebrum, cerebellum, heart, kidney, liver, ovary and testis) across developmental time points from early organogenesis to adulthood for human, rhesus macaque, mouse, rat, rabbit, opossum and chicken. Comparisons of gene expression patterns identified correspondences of developmental stages across species, and differences in the timing of key events during the development of the gonads. We found that the breadth of gene expression and the extent of purifying selection gradually decrease during development, whereas the amount of positive selection and expression of new genes increase. We identified differences in the temporal trajectories of expression of individual genes across species, with brain tissues showing the smallest percentage of trajectory changes, and the liver and testis showing the largest. Our work provides a resource of developmental transcriptomes of seven organs across seven species, and comparative analyses that characterize the development and evolution of mammalian organs.
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| 5. |
- Kandeler, Ellen, et al.
(författare)
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The mineralo-sphere – Succession and physiology of bacteria and fungi colonising pristine minerals in grassland soils under different land-use intensities
- 2019
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 136
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Tidskriftsartikel (refereegranskat)abstract
- The mineralo-sphere is an important micro habitat in terrestrial ecosystems. How different groups of microorganisms colonise mineral surfaces and whether the level of grassland land-use intensity (LUI) modifies this micro-habitat is not well known, however. We exposed mesh containers filled with pristine soil minerals (illite/goethite) mixed with 13C labelled root litter of Dactylis glomerata and Lolium perenne in grassland soils of the “Schwäbische Alb” (Germany) to characterise the succession of different microbial properties in the mineralo-sphere. The use of sites within the Biodiversity Exploratories made it possible to select five sites of low LUI and five sites of high LUI. After 1, 2, 7, 12 and 31 months of exposure in the grassland soils, we used physiological, microbiological and isotopic methods to elucidate in situ colonisation patterns, carbon use and levels of extracellular enzyme expression by soil microorganisms associated with mineral surfaces. Microorganisms slowly colonised pristine mineral surfaces and established functionally distinct communities over time. Fungi colonised mineral surfaces to a greater extent than bacteria, reaching 13.2% of control soils compared to 3.2% by bacteria after 31 months. Fungi also reached pristine mineral surfaces earlier than bacteria, probably due to their hyphal growth strategies, and made immediate use of the added complex root litter substrate. This result is evident by the incorporation of up to 74% root litter-derived C into the fungus-specific PLFA (18:2ω6,9) compared to 51% root litter-derived C in the bacteria-specific PLFAs. Both bacteria and fungi associated with minerals remained in an active state (high biomass-specific respiration, high bacterial and fungal growth rates) throughout the experimental period. Grassland LUI and physico-chemical properties of the adjacent soil modified both quantity and quality of substrates available to soil microorganisms in the mineralo-sphere. Since 13C incorporation into microbial biomass was greater under low LUI than under high LUI, we conclude that microorganisms in low LUI sites had to rely on the added root material, while the carbon signal in microorganisms in the high LUI sites was diluted by alternative sources resulting from transport of dissolved organic carbon into the mineralo-sphere.
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| 6. |
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| 7. |
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| 8. |
- Miguel, Luis Silva, et al.
(författare)
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Cost-effectiveness of semaglutide 2.4 mg in chronic weight management in Portugal
- 2024
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Ingår i: Diabetology & Metabolic Syndrome. - : BioMed Central (BMC). - 1758-5996. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Obesity and overweight are a significant public health concern. Subcutaneous semaglutide 2.4 mg injection is a glucagon-like peptide-1 (GLP-1) analogue approved by the European Medicines Agency as an adjunct to a reduced calorie diet and increased physical activity (diet and exercise, D&E) for the treatment obesity and overweight in the presence of at least one weight related comorbidity. This study aimed to assess the cost-effectiveness of semaglutide 2.4 mg in combination with D&E compared to D&E alone for the Portuguese setting.Methods Analysis were conducted using the Core Obesity Model (COM) version 18, a Markov state transition cohort model, to predict the health outcomes and costs of weight related complications based on changes in surrogate endpoints. Efficacy and safety data were sourced from the STEP trials (Body Mass Index, systolic blood pressure and glycemic status) from a cohort of adults aged on average 48 years with obesity (BMI >= 30 kg/m2) and >= 1 obesity-related comorbidities, over a time horizon of 40 years. Costs were estimated from the perspective of the Portuguese National Health Service. Sensitivity analyses were conducted to test the robustness of results across a range of assumptions.Results On a patient level, Semaglutide 2.4 mg in addition to D&E compared to D&E alone, improved QALYs by 0.098 and yielded higher costs by 1,325 EUR over a 40-year time horizon, with an ICER of 13,459 EUR per QALY gained and 100% probability of cost-effectiveness at the given WTP. Semaglutide 2.4 mg remained cost-effective across all different scenarios and sensitivity analysis at a WTP of 20,000 EUR per QALY. Among the subpopulations examined, Semaglutide 2.4 mg yielded ICERs of 18,459 EUR for patients with BMI >= 30 kg/m2 and of 22,657 EUR for patients with BMI >= 35 kg/m2.Conclusions Semaglutide 2.4 mg was cost-effective compared to D&E alone for patients with obesity (BMI >= 30 kg/m2) and weight related comorbidities in Portugal, over a 40-year time horizon.
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| 9. |
- Rabow, Sandra, et al.
(författare)
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Can heavy metal pollution induce soil bacterial community resistance to antibiotics in boreal forests?
- 2023
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 60:2, s. 237-250
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of microbial antibiotic resistance is a central threat to global health, food security, and development. It has been shown that heavy metal pollution can give rise to microbial resistance to antibiotics, but how wide-spread this phenomenon is remains an open question that urgently needs filling to enable appropriate environmental risk assessments. Here, we determined whether long-term differences in heavy metal pollution in boreal forests had affected soil microbial communities such that they had increased microbial resistance to antibiotics. First, we assessed variation in metal concentrations in samples collected across a distance trajectory from the pollution source, and also the microbial rates and levels of bacterial community resistance to the heavy metal Cu and the antibiotics tetracycline and vancomycin in those samples. Second, we tested if the exposure to Cu or tetracycline could increase bacterial community resistance to Cu and to antibiotics in soils with high versus low background levels of metal contamination. Metal pollution had affected microbial community structures and suppressed decomposer functioning. Importantly, bacterial community Cu resistance increased with higher metal concentrations, which coincided with an induced bacterial community resistance to tetracycline, but not to vancomycin. Laboratory experiments revealed that bacterial community Cu resistance could be further induced in both the low and high end of the pollution gradient, but also that these short-term inductions of community metal tolerance did not coincide with enhanced antibiotic resistance. This yielded a surprising negative correlation between long-term and short-term effects by metals on microbial metal and antibiotic resistances. One mechanism that could provide protection against both metal cations and tetracycline is the small multidrug resistance (SMR) family, which is an energy demanding physiological mechanism that may take time to confer protection. This may explain the different microbial responses to long-term gradients and metal addition experiments. Policy implications. We show that metal pollution in boreal forests will promote soil bacterial antibiotic resistance, revealing a so far unrecognized reservoir of microbial antibiotic resistance. We recommend that environmental risk assessments for any activity giving rise to increased soil metal concentrations need to also consider the induction of microbial antibiotic resistance.
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| 10. |
- Silva-Sánchez, Alex, et al.
(författare)
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Testing the dependence of microbial growth and carbon use efficiency on nitrogen availability, pH, and organic matter quality
- 2019
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 134, s. 25-35
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Tidskriftsartikel (refereegranskat)abstract
- Microbial carbon use efficiency (CUE), or the partitioning of assimilated C into growth or respiration, is a key parameter that is central to understanding the soil C cycle and its feedback to environmental and climate change. The availability of nitrogen (N), organic matter (OM) quality and environmental factors influence CUE indirectly by affecting growth rates and respiration of the major microbial decomposers in soil, including fungi and bacteria. In the present study we set out to evaluate the effect of N-additions (mineral N fertiliser), increased pH (lime), and increased OM quality (plant litter addition) on microbial growth, respiration, and resulting CUE. We sampled beech and spruce forest stands each including two levels of soil fertility. In laboratory microcosm experiments we then manipulated the availability of mineral N, pH and OM quality during the course of 60 days and measured rates of bacterial and fungal growth, respiration, and resulting CUE. We observed that growth rates of both bacteria and fungi were stimulated by increased OM quality through litter additions, but when combined with increased pH, the ratio shifted in favour of bacteria, while a shift towards fungal dominance was observed when litter was combined with N additions. Overall bacterial growth was stimulated by increased pH and reduced by addition of mineral N, while fungal growth appeared unaffected by both factors. The ratio of fungal to bacterial growth varied between 0.02 and 0.7, suggesting that 0.4 to 50 times more detrital-C was used by bacteria than by fungi in the dataset. Consistently negative correlations between fungal and bacterial growth suggested competitive interactions during the microbial use of detrital C, with bacteria being the dominant competitor. Estimated levels of microbial CUE ranged from <0.05 to 0.5, and higher levels of CUE were associated with higher dominance of bacteria in soils with higher pH and lower N availability. Taken together, differences in CUE were linked to the dominance of fungi or bacteria. When bacterial growth was inhibited by mineral N or low pH, a competitive release resulted in a stimulated fungal growth and detrital C-use, which yielded reduced CUEs.
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| 11. |
- Soares, Margarida, et al.
(författare)
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Can heavy metal pollution stress reduce microbial carbon-use efficiencies?
- 2024
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Ingår i: Soil Biology and Biochemistry. - 0038-0717. ; 195
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Tidskriftsartikel (refereegranskat)abstract
- The fate of soil organic matter (OM) is determined by its microbial use for growth or respiration. Many environmental factors influence microbial OM use, including the presence of contaminants and toxins in the environment, such as heavy metals. We evaluated short- and long-term responses of microbial processes to metal contamination by estimating biomass concentrations and growth rates of bacteria and fungi, respiration, and the resulting microbial carbon-use efficiencies (CUE), and microbial turnover times. We sampled O-horizon from a gradient in boreal forest soils exposed to long-term heavy metal contamination arising from industrial point source since the 1930s to assess long-term effects on soil microorganisms. To estimate microbial responses to short-term metal exposure, additions of Cu were used. Bacterial growth rates and respiration rates decreased in response to long-term metal contamination, while fungal growth rates were unaffected, without changes in CUEs. Bacterial biomass concentrations were independent of soil metal concentrations while fungal and total biomass decreased. Thus, turnover times for bacteria were slowed while fungal turnover times were accelerated by metal pollution. Bacterial growth was inhibited and fungal growth stimulated by experimental Cu additions, with bigger effect sizes in contaminated sites. We interpreted the low rates of growth but high biomass in collected soil samples to indicate that the fungal community included a large mycorrhizal fraction. Although Cu additions decreased the overall microbial OM-use (i.e., the sum of fungal and bacterial growth and total respiration), they also increased the CUE. In conclusion, fungal OM-use was less sensitive than bacterial to metal pollution and the CUE was unaffected. Microbial decomposer communities in contaminated soils were also able to maintain higher CUE when challenged with new metal additions. Our results imply that microbial communities align their trait compositions to environmental challenges, and that this can mitigate the reduction in microbial carbon-use efficiencies that often is expected to occur from environmental stress.
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| 12. |
- Soares, Margarida
(författare)
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Fungal and bacterial contributions to decomposition in terrestrial and aquatic ecosystems
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Microbial decomposers process a great majority of net primary production in the biosphere and regulate carbon (C) and nutrient cycling. Microbial communities are extremely diverse and often disregarded from global C-cycling models, but one strategy to overcome this challenge is to focus on the major decomposer groups: fungi and bacteria. These groups have distinct life strategies and are differently affected by environmental factors. During microbial decomposition of organic matter (OM), the fraction of C assimilated into microbial growth or used in cell maintenance and respiration is defined as microbial carbon-use efficiency (CUE). Since soils represent a large C pool with a critical role in regulating atmospheric CO2 concentrations, CUE is a key parameter central to understanding the soil C-cycle and its feedback to environmental change. In this thesis I compared the bacterial and fungal contributions to decomposition by developing conversion factors to measure microbial growth in units of C. I estimated CUE and studied the influence of environmental factors on the fungal-to-bacterial ratio (F:B) and how that affects CUE. This was applied to a survey of field sites and verified in laboratory microcosms. CUE was higher in sites with low F:B ratio, and within field sites higher CUE was associated to lower F:B in high fertility soils. However, in microcosms, higher CUE was a result of low F:B in low mineral N and high pH soils, with no effect of OM quality. This indicated that CUE was also regulated by another component of soil fertility other than mineral N, pH or OM availability, and I suggest that plant community traits such as litter and rhizosphere inputs might influence F:B ratio and CUE. I also investigated the effect of long and short term-stress on CUE in a subartic region. CUE was unaffected by increasing metal concentrations along a gradient of long-term contamination. Fungi were overall less affected by heavy metal pollution than bacteria but F:B and CUE were unrelated. In experimental microcosms I tested the effect of short-term stress with heavy metals in both soils previously exposed to stress and unexposed soils. CUE decreased only in unexposed soils, but by the end of the experimental period previously stressed soils exposed to heavy metals had higher CUE than unexposed soils because adapted microbial decomposers could allocate more resources to growth than to maintenance and survival.The differences between fungal and bacterial decomposition of plant litter in aquatic and terrestrial systems were explored in a boreal catchment forest site, where litter bags were installed in soils and adjacent streams. F:B ratios were higher in litter decomposing in streams than in soils but overall mass loss was higher in soils. Litter decomposition was explored with IR spectroscopy and litter changes in terms of chemical functional groups (carbohydrate and aromatic compound loss) were fundamentally different between systems. The effect of a labile C source on litter decomposing in aquatic systems was tested in laboratory microcosms. I investigated the priming effect - increased mineralization of native OM in response to a external labile C source- on biofilms growth in plant litter. In these systems the spatial proximity between photosynthetic algae and microbial decomposers allows for products of metabolisms to be exchanged. I found that labile C of photosynthetic algae origin did not affect the decomposition of plant litter in terms of mass loss but increased the fungal removal of N from plant litter.In conclusion, microbial growth rates in C units and CUE can now be estimated in natural environments. This thesis provides a deeper understanding of the fungal and bacterial contributions to decomposition in different systems, and how F:B and CUE are regulated by environmental factors.
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| 13. |
- Soares, Margarida, et al.
(författare)
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Labile carbon 'primes' fungal use of nitrogen from submerged leaf litter
- 2017
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Ingår i: FEMS Microbiology Ecology. - : Oxford University Press (OUP). - 1574-6941. ; 93:9
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Tidskriftsartikel (refereegranskat)abstract
- Microbial decomposers colonising submerged leaf litter are in close spatial proximity with periphytic algae and can use carbon (C) exudates released during photosynthesis. We investigated whether labile C delivered as algal exudates could affect the microbial colonisation and decomposition of leaf litter. Using microcosms, we submerged leaf litter in pond water and monitored fungal and bacterial growth over time and tested the effect of algal photosynthetic exudates by comparing microcosms in light and dark. In order to experimentally assign the effect of algal products to labile C delivery and test for a C driven mechanism, we ran a parallel experiment with microcosms in the dark where we mimicked the delivery of algal labile C by continuously adding glucose. Labile C delivered as algal exudates or glucose resulted in a dominance of fungal decomposers over bacteria, and stimulated the acquisition of more N-rich OM fractions from litter during periods of active fungal growth. Our results highlight that labile C stimulates fungal decomposers and increases N removal from leaf litter. Since fungal necromass is more resistant to degradation than bacterial, we expect that a fungal-dominated litter degradation might contribute to more protected C pools.
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| 14. |
- Soares, Margarida, et al.
(författare)
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Microbial growth and carbon use efficiency in soil : Links to fungal-bacterial dominance, SOC-quality and stoichiometry
- 2019
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 131, s. 195-205
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Tidskriftsartikel (refereegranskat)abstract
- Microbial decomposers are responsible for the breakdown of organic matter (OM) and thus regulate soil carbon (C) stocks. During the decomposition of OM, microorganisms can use the assimilated C for biomass production or respire it as CO2, and the fraction of growth to total assimilation defines the microbial carbon-use efficiency (CUE). As such, CUE has direct consequences for how microbial decomposers affect the balance of C between atmosphere and soil. We estimated fungal and bacterial growth in C units in microcosm systems with submerged plant litter. We established conversion factors between bacterial and fungal growth to biomass and applied this to a dataset representing 9 different sites in temperate forest soils, temperate agricultural soils, and subarctic forest soils, to estimate growth rates of fungi and bacteria in units of C, to estimate the dominance of the two decomposer groups, and to compare these values to respiration to estimate the microbial CUE. We observed that fungal-to-bacterial growth ratios (F:B) ranged from 0.02 to 0.44, and that the fungal dominance was higher in soils with lower C:N ratio and higher C-quality. We found a negative exponential relationship between the dominance of fungi and the microbial CUE. CUE ranged from 0.03 to 0.30, and values clustered most strongly according to site rather than level of soil N. CUE was higher in soil with high C:N ratio and high C-quality. However, within each land-use type, a high mineral N-content did result in lower F:B and higher resulting CUE. In conclusion, a higher soil C-quality coincided with lower F:B and higher CUE across the surveyed sites, while a higher N availability did not. A higher N availability resulted in higher CUE and lower F:B within each site suggesting that site-specific differences such as the effect of plant community via e.g. plant litter and rhizosphere input, overrode the influence of N-availability.
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| 15. |
- Urrutia Cordero, Pablo, et al.
(författare)
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Phytoplankton diversity loss along a gradient of future warming and brownification in freshwater mesocosms
- 2017
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Ingår i: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 62:11, s. 1869-1878
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Tidskriftsartikel (refereegranskat)abstract
- 1. Globally, freshwater ecosystems are warming at unprecedented rates and northern temperate lakes are simultaneously experiencing increased runoff of humic substances (brownification), with little known consequences for future conservation of biodiversity and ecosystem functioning.2. We employed an outdoor mesocosm experiment during spring and summer to investigate the combined effects of gradually increasing warming and brownification perturbations on the phytoplankton community structure (biodiversity and composition) and functioning (biomass).3. While we did not observe overall significant treatment effects on total phytoplankton biomasses, we show that predicted increases in warming and brownification can reduce biodiversity considerably, occasionally up to 90% of Shannon diversity estimates. Our results demonstrate that the loss of biodiversity is driven by the dominance of mixotrophic algae (Dinobryon and Cryptomonas), whereas several other phytoplankton taxa may be temporarily displaced from the community, including Cyclotella, Desmodesmus, Monoraphidium, Tetraedron, Nitzschia and Golenkinia.4. The observed loss of biodiversity coincided with an increase in bacterial production providing resources for potential mixotrophs along the gradient of warming and brownification. This coupling between bacterial production and mixotrophs was likely a major cause behind the competitive displacement of obligate phototrophs and supports evidence for the importance of consumer-prey dynamics in shaping environmental impacts on phytoplankton communities.5. We conclude that warming and brownification are likely to cause a profound loss of biodiversity by indirectly affecting competitive interactions among phytoplankton taxa. Importantly, our results did not show an abrupt loss of biodiversity; instead the reduction in taxa richness levelled off after exceeding a threshold of warming and brownification. These results exemplify the complex nonlinear responses of biodiversity to environmental perturbations and provide further insights for predicting biodiversity patterns to the future warming and brownification of freshwaters.
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| 16. |
- Wilken, Susanne, et al.
(författare)
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Primary producers or consumers? : Increasing phytoplankton bacterivory along a gradient of lake warming and browning
- 2018
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Ingår i: Limnology and Oceanography. - : WILEY. - 0024-3590 .- 1939-5590. ; 63:Suppl. 1, s. S142-S155
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Tidskriftsartikel (refereegranskat)abstract
- Eukaryotic phytoplankton form the basis of aquatic food webs and play a key role in the global carbon cycle. Many of these evolutionarily diverse microalgae are also capable of feeding on other microbes, and hence simultaneously act both as primary producers and consumers. The net ecosystem impact of such mixotrophs depends on their nutritional strategy which is likely to alter with environmental change. Many temperate lakes are currently warming at unprecedented rates and are simultaneously increasing in water color (browning) due to increased run-off of humic substances. We hypothesized that the resulting reduction in light intensity and increased bacterial abundances would favor mixotrophic phytoplankton over obligate autotrophs, while higher temperatures might boost their rates of bacterivory. We tested these hypotheses in a mesocosm experiment simulating a gradient of increasing temperature and water color in temperate shallow lakes as expected to occur over the coming century. Mixotrophs showed a faster increase in abundance under the climate change scenario during spring, when they dominated the phytoplankton community. Furthermore, both bacterial abundances and rates of phytoplankton bacterivory increased under future climate conditions. Bacterivory contributed significantly to phytoplankton resource acquisition under future climate conditions, while remaining negligible throughout most of the season in treatments resembling today's conditions. Hence, to our knowledge, we here provide the first evidence for an increasing importance of bacterivory by phytoplankton in future temperate shallow lakes. Such a change in phytoplankton nutritional strategies will likely impact biogeochemical cycles and highlights the need to conceptually integrate mixotrophy into current ecosystem models.
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