scholarly journals Abundance and biogeography of methanogenic and methanotrophic microorganisms across European streams

2019 ◽  
Author(s):  
Magdalena Nagler ◽  
Nadine Praeg ◽  
Georg H. Niedrist ◽  
Katrin Attermeyer ◽  
Núria Catalán ◽  
...  

Abstract Background: Globally, streams emit significant amounts of methane, a highly potent greenhouse gas. However, little is known about the stream sediment microbial communities that control the net methane balance in these systems, and in particular about their distribution and composition at large spatial scales. This study investigated the diversity and abundance of methanogenic archaea and methane-oxidizing microorganisms across 16 European streams (from northern Spain to northern Sweden and from western Ireland to western Bulgaria) via 16S rRNA gene sequencing and qPCR. Furthermore, it examined environmental factors influencing both abundance and community composition and explored the link to measured potential methane production and oxidation rates of the respective sediments. Results: Our results demonstrated that the methanogenic and methanotrophic microbiomes of the studied European streams were linked to both the temperature and degree of anthropogenic alteration. The microbiomes could be separated into two to three groups according to environmental factors at both stream and catchment scales. Main methanogenic taxa found within more anthropogenically-altered, warm, and oxygen-poor environments were either Methanospirillum spp. or members of the families Methanosarcinaceae and Methanobacteriaceae . Within such environments, methane oxidizing communities were strongly characterized by members of the family Methylobacteriaceae ( Meganema spp. and Microvirga spp.). Contrastingly, communities in colder environments rich in oxygen and with relatively little anthropogenic impact at the catchment scale were characterized by the methanogenic Methanosaetaceae , Methanocellaceae and Methanoregulaceae and the methanotrophic Methyloglobulus spp ., members of the CABC2E06 group (all Methylococcaceae ) and by various Candidatus Methanoperedens. Overall, diversity of methanogenic archaea increased with increasing water temperature. Methane oxidizing communities showed higher diversities in southern sampling sites and in streams with larger stream areas and widths. Potential methane production rates significantly increased with increasing abundance of methanogenic archaea, while potential methane oxidation rates did not show significant correlations with abundances of methane oxidizing bacteria, presumably due to the more diverse physiological capabilities of this group. Conclusions: We present the first large scale overview of the large-scale microbial biogeography of two microbial groups driving the methane cycle dynamics within stream sediments and deduce the impact that future anthropogenic alterations may cause.

Polar Biology ◽  
2020 ◽  
Vol 43 (11) ◽  
pp. 1693-1705
Author(s):  
Miriam L. S. Hansen ◽  
Dieter Piepenburg ◽  
Dmitrii Pantiukhin ◽  
Casper Kraan

Abstract In times of accelerating climate change, species are challenged to respond to rapidly shifting environmental settings. Yet, faunal distribution and composition are still scarcely known for remote and little explored seas, where observations are limited in number and mostly refer to local scales. Here, we present the first comprehensive study on Eurasian-Arctic macrobenthos that aims to unravel the relative influence of distinct spatial scales and environmental factors in determining their large-scale distribution and composition patterns. To consider the spatial structure of benthic distribution patterns in response to environmental forcing, we applied Moran’s eigenvector mapping (MEM) on a large dataset of 341 samples from the Barents, Kara and Laptev Seas taken between 1991 and 2014, with a total of 403 macrobenthic taxa (species or genera) that were present in ≥ 10 samples. MEM analysis revealed three spatial scales describing patterns within or beyond single seas (broad: ≥ 400 km, meso: 100–400 km, and small: ≤ 100 km). Each scale is associated with a characteristic benthic fauna and environmental drivers (broad: apparent oxygen utilization and phosphate, meso: distance-to-shoreline and temperature, small: organic carbon flux and distance-to-shoreline). Our results suggest that different environmental factors determine the variation of Eurasian-Arctic benthic community composition within the spatial scales considered and highlight the importance of considering the diverse spatial structure of species communities in marine ecosystems. This multiple-scale approach facilitates an enhanced understanding of the impact of climate-driven environmental changes that is necessary for developing appropriate management strategies for the conservation and sustainable utilization of Arctic marine systems.


2007 ◽  
Vol 73 (14) ◽  
pp. 4609-4618 ◽  
Author(s):  
Samuel Ohene-Adjei ◽  
Ronald M. Teather ◽  
Michael Ivan ◽  
Robert J. Forster

ABSTRACT Association patterns between archaea and rumen protozoa were evaluated by analyzing archaeal 16S rRNA gene clone libraries from ovine rumen inoculated with different protozoa. Five protozoan inoculation treatments, fauna free (negative control), holotrich and cellulolytic protozoa, Isotricha and Dasytricha spp., Entodinium spp., and total fauna (type A) were tested. We used denaturing gradient gel electrophoresis, quantitative PCR, and phylogenetic analysis to evaluate the impact of the protozoan inoculants on the respective archaeal communities. Protozoan 18S ribosomal DNA clone libraries were also evaluated to monitor the protozoal population that was established by the inoculation. Phylogenetic analysis suggested that archaeal clones associated with the fauna-free, the Entodinium, and the type A inoculations clustered primarily with uncultured phylotypes. Polyplastron multivesiculatum was the predominant protozoan strain established by the holotrich and cellulolytic protozoan treatment, and this resulted predominantly in archaeal clones affiliated with uncultured and cultured methanogenic phylotypes (Methanosphaera stadtmanae, Methanobrevibacter ruminantium, and Methanobacterium bryantii). Furthermore, the Isotricha and Dasytricha inoculation treatment resulted primarily in archaeal clones affiliated with Methanobrevibacter smithii. This report provides the first assessment of the influence of protozoa on archaea within the rumen microbial community and provides evidence to suggest that different archaeal phylotypes associate with specific groups of protozoa. The observed patterns may be linked to the evolution of commensal and symbiotic relationships between archaea and protozoa in the ovine rumen environment. This report further underscores the prevalence and potential importance of a rather large group of uncultivated archaea in the ovine rumen, probably unrelated to known methanogens and undocumented in the bovine rumen.


2011 ◽  
Vol 77 (16) ◽  
pp. 5682-5687 ◽  
Author(s):  
Erin E. King ◽  
Rachel P. Smith ◽  
Benoit St-Pierre ◽  
André-Denis G. Wright

ABSTRACTIn the dairy cattle industry, Holstein and Jersey are the breeds most commonly used for production. They differ in performance by various traits, such as body size, milk production, and milk composition. With increased concerns about the impact of agriculture on climate change, potential differences in other traits, such as methane emission, also need to be characterized further. Since methane is produced in the rumen by methanogenic archaea, we investigated whether the population structure of methanogen communities would differ between Holsteins and Jerseys. Breed-specific rumen methanogen 16S rRNA gene clone libraries were constructed from pooled PCR products obtained from lactating Holstein and Jersey cows, generating 180 and 185 clones, respectively. The combined 365 sequences were assigned to 55 species-level operational taxonomic units (OTUs). Twenty OTUs, representing 85% of the combined library sequences, were common to both breeds, while 23 OTUs (36 sequences) were found only in the Holstein library and 12 OTUs (18 sequences) were found only in the Jersey library, highlighting increased diversity in the Holstein library. Other differences included the observation that sequences with species-like sequence identity toMethanobrevibacter milleraewere represented more highly in the Jersey breed, whileMethanosphaera-related sequences and novel uncultured methanogen clones were more frequent in the Holstein library. In contrast, OTU sequences with species-level sequence identity toMethanobrevibacter ruminantiumwere represented similarly in both libraries. Since the sampled animals were from a single herd consisting of two breeds which were fed the same diet and maintained under the same environmental conditions, the differences we observed may be due to differences in host breed genetics.


Author(s):  
José Luis Acuña ◽  
Araceli Puente ◽  
Ricardo Anadón ◽  
Consolación Fernández ◽  
María Luisa Vera ◽  
...  

Following the accident of the oil tanker ‘Prestige’, we surveyed the large scale fuel deposition patterns on the Cantabrian shore (northern Spain) covering three regions (from west to east): (i) Asturias, west of Cape Peñas (24 segments surveyed); (ii) Asturias, east of Cape Peñas (33 segments surveyed); and (iii) Cantabria (also east of Cape Peñas, 256 segments surveyed). Fuel arrived to the Cantabrian Coast as a single oil wave which was more intense to the east than to the west of Cape Peñas. The mean percentage of coast length affected was 25, 41 and 15% in western Asturias, eastern Asturias and Cantabria, respectively. However, less than 10% of the substrate was covered by fuel in oiled patches, thus the impact was moderate. We conclude that these patterns are consistent with fuel transport by the Iberian Poleward Current, a hydrographic feature typical of this region during winter.


2019 ◽  
Vol 627 ◽  
pp. A131 ◽  
Author(s):  
M. Cousin ◽  
P. Guillard ◽  
M. D. Lehnert

Context. Star formation in galaxies is inefficient, and understanding how star formation is regulated in galaxies is one of the most fundamental challenges of contemporary astrophysics. Radiative cooling, feedback from supernovae and active galactic nuclei (AGN), and large-scale dynamics and dissipation of turbulent energy act over various time and spatial scales and all regulate star formation in a complex gas cycle. Aims. This paper presents the physics implemented in a new semi-analytical model of galaxy formation and evolution called the Galaxy Assembler from dark-matter Simulation (G.A.S.). Methods. The fundamental underpinning of our new model is the development of a multiphase interstellar medium (ISM) in which energy produced by supernovae and AGN maintains an equilibrium between a diffuse, hot, and stable gas and a cooler, clumpy, and low-volume filling factor gas. The hot gas is susceptible to thermal and dynamical instabilities. We include a description of how turbulence leads to the formation of giant molecular clouds through an inertial turbulent energy cascade, assuming a constant kinetic energy transfer per unit volume. We explicitly modelled the evolution of the velocity dispersion at different scales of the cascade and accounted for thermal instabilities in the hot halo gas. Thermal instabilities effectively reduce the impact of radiative cooling and moderates accretion rates onto galaxies, and in particular, for those residing in massive haloes. Results. We show that rapid and multiple exchanges between diffuse and unstable gas phases strongly regulates star formation rates in galaxies because only a small fraction of the unstable gas is forming stars. We checked that the characteristic timescales describing the gas cycle, gas depletion timescale, and star-forming laws at different scales are in good agreement with observations. For high-mass haloes and galaxies, cooling is naturally regulated by the growth of thermal instabilities, so we do not need to implement strong AGN feedback in this model. Our results are also in good agreement with the observed stellar mass function from z ≃ 6.0 to z ≃ 0.5. Conclusion. Our model offers the flexibility to test the impact of various physical processes on the regulation of star formation on a representative population of galaxies across cosmic times. Thermal instabilities and the cascade of turbulent energy in the dense gas phase introduce a delay between gas accretion and star formation, which keeps galaxy growth inefficient in the early Universe. The main results presented in this paper, such as stellar mass functions, are available in the GALAKSIENN library.


2012 ◽  
Vol 12 (19) ◽  
pp. 9335-9353 ◽  
Author(s):  
H. G. Ouwersloot ◽  
J. Vilà-Guerau de Arellano ◽  
A. C. Nölscher ◽  
M. C. Krol ◽  
L. N. Ganzeveld ◽  
...  

Abstract. We studied the atmospheric boundary layer (ABL) dynamics and the impact on atmospheric chemistry during the HUMPPA-COPEC-2010 campaign. We used vertical profiles of potential temperature and specific moisture, obtained from 132 radio soundings, to determine the main boundary layer characteristics during the campaign. We propose a classification according to several main ABL prototypes. Further, we performed a case study of a single day, focusing on the convective boundary layer, to analyse the influence of the dynamics on the chemical evolution of the ABL. We used a mixed layer model, initialized and constrained by observations. In particular, we investigated the role of large scale atmospheric dynamics (subsidence and advection) on the ABL development and the evolution of chemical species concentrations. We find that, if the large scale forcings are taken into account, the ABL dynamics are represented satisfactorily. Subsequently, we studied the impact of mixing with a residual layer aloft during the morning transition on atmospheric chemistry. The time evolution of NOx and O3 concentrations, including morning peaks, can be explained and accurately simulated by incorporating the transition of the ABL dynamics from night to day. We demonstrate the importance of the ABL height evolution for the representation of atmospheric chemistry. Our findings underscore the need to couple the dynamics and chemistry at different spatial scales (from turbulence to mesoscale) in chemistry-transport models and in the interpretation of observational data.


2020 ◽  
Author(s):  
Daniel Tajmel ◽  
Carla Cruz Paredes ◽  
Johannes Rousk

<p>Terrestrial biogeochemical cycles are regulated by soil microorganisms. The microbial carbon release due to respiration and carbon sequestration through microbial growth determine whether soils become sources or sinks for carbon. Temperature i​s one of the most important environmental factors controlling both microbial growth and respiration. Therefore, to understand the influence of temperature on microbial processes is crucial. One strategy to predict how ecosystems will respond to warming is to use geographical ecosystem differences, in space-for-time (SFT) substitution approaches. We hypothesized (1) that microbes should be adapted to their environmental temperature leading to microbial communities with warm-shifted temperature relationships in warmer environments, and vice versa. Furthermore, we hypothesized  (2) that other factors should not influence microbial temperature relationships, and (3) that the temperature sensitivity of microbial processes (Q10) should be linked to the microbial temperature relationships.</p><p> </p><p>In this project, we investigated the effects of environmental temperature on microbial temperature relationships for microbial growth and respiration along a natural climate gradient along a transect across Europe to predict the impact of a warming climate. The transect was characterized by mean annual temperature (MAT) ranging from - 4 degrees Celsius (Greenland) to 18 degrees Celsius (Southern Spain), while other environmental factor ranges were broad and unrelated to climate, including pH from 4.0 to 8.8, C/N ratio from 7 to 50, SOM from 4% to 94% and plant communities ranging from arctic tundra to Mediterranean grasslands. More than 56 soil samples were analyzed and microbial temperature relationships were determined using controlled short-term laboratory incubations from 0 degrees Celsius to 45 degrees Celsius. The link between microbial temperature relationship and the climate was assessed by using the relationship between the environmental temperature and indices for microbial temperature relationships including the minimum (T<sub>min</sub>), optimum (T<sub>opt</sub>) and maximum temperature (T<sub>max</sub>) for microbial growth as well as for respiration. To estimate the T<sub>min</sub>, T<sub>opt </sub>and T<sub>max </sub>the square root equation, the Ratkowsky model was used.</p><p> </p><p>We found that microbial communities were adapted to their environmental temperature. The microbial temperature relationship was stronger for microbial growth than for respiration. For 1 degrees Celsius rise in MAT, T<sub>min </sub>increased 0.22 degrees Celsius for bacterial and 0.28 degrees Celsius for fungal growth, while T<sub>min </sub>for respiration increased by 0.16 per 1 degrees Celsius rise. T<sub>min </sub>was also found to be universally linked to Q10, such that higher T<sub>min </sub>resulted in higher Q10. Other environmental factors (pH, C/N ratio, SOM, vegetation cover) did not influence the temperature relationships. By incorporating the determined relationships between environmental temperature and microbial growth and respiration into large scale ecosystem models, we can get a better understanding of the influence of microbial adaptation to warmer climate on the C-exchange between soils and atmosphere.</p>


2021 ◽  
Vol 9 ◽  
Author(s):  
Kyla M. Dahlin ◽  
Phoebe L. Zarnetske ◽  
Quentin D. Read ◽  
Laura A. Twardochleb ◽  
Aaron G. Kamoske ◽  
...  

Global declines in biodiversity have the potential to affect ecosystem function, and vice versa, in both terrestrial and aquatic ecological realms. While many studies have considered biodiversity-ecosystem function (BEF) relationships at local scales within single realms, there is a critical need for more studies examining BEF linkages among ecological realms, across scales, and across trophic levels. We present a framework linking abiotic attributes, productivity, and biodiversity across terrestrial and inland aquatic realms. We review examples of the major ways that BEF linkages form across realms–cross-system subsidies, ecosystem engineering, and hydrology. We then formulate testable hypotheses about the relative strength of these connections across spatial scales, realms, and trophic levels. While some studies have addressed these hypotheses individually, to holistically understand and predict the impact of biodiversity loss on ecosystem function, researchers need to move beyond local and simplified systems and explicitly investigate cross-realm and trophic interactions and large-scale patterns and processes. Recent advances in computational power, data synthesis, and geographic information science can facilitate studies spanning multiple ecological realms that will lead to a more comprehensive understanding of BEF connections.


2019 ◽  
Vol 23 (7) ◽  
pp. 2863-2875 ◽  
Author(s):  
Sungmin O ◽  
Ulrich Foelsche

Abstract. Hydrology and remote-sensing communities have made use of dense rain-gauge networks for studying rainfall uncertainty and variability. However, in most regions, these dense networks are only available at small spatial scales (e.g., within remote-sensing subpixel areas) and over short periods of time. Just a few studies have applied a similar approach, i.e., employing dense gauge networks to catchment-scale areas, which limits the verification of their results in other regions. Using 10-year rainfall measurements from a network of 150 rain gauges, WegenerNet (WEGN), we assess the spatial uncertainty in observed heavy rainfall events. The WEGN network is located in southeastern Austria over an area of 20 km × 15 km with moderate orography. First, the spatial variability in rainfall in the region was characterized using a correlogram at daily and sub-daily scales. Differences in the spatial structure of rainfall events between warm and cold seasons are apparent, and we selected heavy rainfall events, the upper 10 % of wettest days during the warm season, for further analyses because of their high potential for causing hazards. Secondly, we investigated the uncertainty in estimating mean areal rainfall arising from a limited gauge density. The average number of gauges required to obtain areal rainfall with errors less than a certain threshold (≤20 % normalized root-mean-square error – RMSE – is considered here) tends to increase, roughly following a power law as the timescale decreases, while the errors can be significantly reduced by establishing regularly distributed gauges. Lastly, the impact of spatial aggregation on extreme rainfall was examined, using gridded rainfall data with various horizontal grid spacings. The spatial-scale dependence was clearly observed at high intensity thresholds and high temporal resolutions; e.g., the 5 min extreme intensity increases by 44 % for the 99.9th and by 25 % for the 99th percentile, with increasing horizontal resolution from 0.1 to 0.01∘. Quantitative uncertainty information from this study can guide both data users and producers to estimate uncertainty in their own observational datasets, consequently leading to the sensible use of the data in relevant applications. Our findings could be transferred to midlatitude regions with moderate topography, but only to a limited extent, given that regional factors that can affect rainfall type and process are not explicitly considered in the study.


2021 ◽  
Vol 13 (11) ◽  
pp. 6129
Author(s):  
Robyn Horan ◽  
Pawan S. Wable ◽  
Veena Srinivasan ◽  
Helen E. Baron ◽  
Virginie J. D. Keller ◽  
...  

There has been renewed interest in the performance, functionality, and sustainability of traditional small-scale storage interventions (check dams, farm bunds and tanks) used within semi-arid regions for the improvement of local water security and landscape preservation. The Central Groundwater Board of India is encouraging the construction of such interventions for the alleviation of water scarcity and to improve groundwater recharge. It is important for water resource management to understand the hydrological effect of these interventions at the basin scale. The quantification of small-scale interventions in hydrological modelling is often neglected, especially in large-scale modelling activities, as data availability is low and their hydrological functioning is uncertain. A version of the Global Water Availability Assessment (GWAVA) water resources model was developed to assess the impact of interventions on the water balance of the Cauvery Basin and two smaller sub-catchments. Model results demonstrate that farm bunds appear to have a negligible effect on the average annual simulated streamflow at the outlets of the two sub-catchments and the basin, whereas tanks and check dams have a more significant and time varying effect. The open water surface of the interventions contributed to an increase in evaporation losses across the catchment. The change in simulated groundwater storage with the inclusion of interventions was not as significant as catchment-scale literature and field studies suggest. The model adaption used in this study provides a step-change in the conceptualisation and quantification of the consequences of small-scale storage interventions in large- or basin-scale hydrological models.


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