scholarly journals Temporal dynamics of nitrogen cycle gene diversity in a hyporheic microbiome

2019 ◽  
Author(s):  
William C. Nelson ◽  
Emily B. Graham ◽  
Alex R. Crump ◽  
Sarah J. Fansler ◽  
Evan V. Arntzen ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Nitrogen Cycle ◽  
Hyporheic Zone ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Gene Diversity ◽  
Optimal Growth ◽  
Community Function ◽  
Level Function ◽  
Denitrification Genes

ABSTRACTBiodiversity is thought to prevent decline in community function in response to changing environmental conditions through replacement of organisms with similar functional capacity but different optimal growth characteristics. We examined how this concept translates to the within-gene level by exploring seasonal dynamics of within-gene diversity for genes involved in nitrogen cycling in hyporheic zone communities. Nitrification genes displayed low richness— defined as the number of unique within-gene phylotypes—across seasons. Conversely, denitrification genes varied in both richness and the degree to which phylotypes were recruited or lost. These results demonstrate that there is not a universal mechanism for maintaining community functional potential for nitrogen cycling activities, even across seasonal environmental shifts to which communities would be expected to be well adapted. As such, extreme environmental changes could have very different effects on the stability of the different nitrogen cycle activities. These outcomes suggest a need to modify existing conceptual models that link biodiversity to microbiome function to incorporate within-gene diversity. Specifically, we suggest an expanded conceptualization that (1) recognizes component steps (genes) with low diversity as potential bottlenecks influencing pathway-level function, and (2) includes variation in both the number of entities (e.g. species, phylotypes) that can contribute to a given process and the turnover of those entities in response to shifting conditions. Building these concepts into process-based ecosystem models represents an exciting opportunity to connect within-gene-scale ecological dynamics to ecosystem-scale services.

scholarly journals A three-dimensional view on biodiversity changes: spatial, temporal, and functional perspectives on fish communities in the Baltic Sea

2018 ◽  
Vol 75 (7) ◽  
pp. 2463-2475 ◽  
Author(s):  
Romain Frelat ◽  
Alessandro Orio ◽  
Michele Casini ◽  
Andreas Lehmann ◽  
Bastien Mérigot ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Fish Communities ◽  
The Baltic Sea ◽  
Functional Richness ◽  
Holistic Understanding ◽  
The Baltic

Abstract Fisheries and marine ecosystem-based management requires a holistic understanding of the dynamics of fish communities and their responses to changes in environmental conditions. Environmental conditions can simultaneously shape the spatial distribution and the temporal dynamics of a population, which together can trigger changes in the functional structure of communities. Here, we developed a comprehensive framework based on complementary multivariate statistical methodologies to simultaneously investigate the effects of environmental conditions on the spatial, temporal and functional dynamics of species assemblages. The framework is tested using survey data collected during more than 4000 fisheries hauls over the Baltic Sea between 2001 and 2016. The approach revealed the Baltic fish community to be structured into three sub-assemblages along a strong and temporally stable salinity gradient decreasing from West to the East. Additionally, we highlight a mismatch between species and functional richness associated with a lower functional redundancy in the Baltic Proper compared with other sub-areas, suggesting an ecosystem more susceptible to external pressures. Based on a large dataset of community data analysed in an innovative and comprehensive way, we could disentangle the effects of environmental changes on the structure of biotic communities—key information for the management and conservation of ecosystems.

scholarly journals Temporal Dynamics of Cloacal Microbiota in Adult Laying Chickens With and Without Access to an Outdoor Range

2021 ◽  
Vol 11 ◽  
Author(s):  
Janneke Schreuder ◽  
Francisca C. Velkers ◽  
Alex Bossers ◽  
Ruth J. Bouwstra ◽  
Willem F. de Boer ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Composition ◽  
Intestinal Microbiota ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Microbial Community Composition ◽  
Sudden Change ◽  
Rrna Gene ◽  
Poultry House ◽  
Over Time

Associations between animal health and performance, and the host’s microbiota have been recently established. In poultry, changes in the intestinal microbiota have been linked to housing conditions and host development, but how the intestinal microbiota respond to environmental changes under farm conditions is less well understood. To gain insight into the microbial responses following a change in the host’s immediate environment, we monitored four indoor flocks of adult laying chickens three times over 16 weeks, during which two flocks were given access to an outdoor range, and two were kept indoors. To assess changes in the chickens’ microbiota over time, we collected cloacal swabs of 10 hens per flock and performed 16S rRNA gene amplicon sequencing. The poultry house (i.e., the stable in which flocks were housed) and sampling time explained 9.2 and 4.4% of the variation in the microbial community composition of the flocks, respectively. Remarkably, access to an outdoor range had no detectable effect on microbial community composition, the variability of microbiota among chickens of the same flock, or microbiota richness, but the microbiota of outdoor flocks became more even over time. Fluctuations in the composition of the microbiota over time within each poultry house were mainly driven by turnover in rare, rather than dominant, taxa and were unique for each flock. We identified 16 amplicon sequence variants that were differentially abundant over time between indoor and outdoor housed chickens, however none were consistently higher or lower across all chickens of one housing type over time. Our study shows that cloacal microbiota community composition in adult layers is stable following a sudden change in environment, and that temporal fluctuations are unique to each flock. By exploring microbiota of adult poultry flocks within commercial settings, our study sheds light on how the chickens’ immediate environment affects the microbiota composition.

Surface-groundwater interactions in karst: overview, concept and mapping

2021 ◽  
Author(s):  
Natasa Ravbar ◽  
Cyril Mayaud ◽  
Matej Blatnik ◽  
Metka Petrič
Keyword(s):  
Environmental Changes ◽  
Temporal Dynamics ◽  
Field Measurements ◽  
Spatial Dimension ◽  
Karst Aquifers ◽  
Wetland Ecosystems ◽  
Spatial And Temporal Dynamics ◽  
Ecohydrological Processes

<p>Under special meteorological and hydrological circumstances, shallow karst areas and karst poljes may experience surface water overflow. As a result, surface- groundwater interaction occurs usually creating intermittent lakes. Although human settlements and activities have traditionally adapted to these natural conditions, extensive temporary floods are classified among the most common natural disasters in karst. On the other hand, intermittent lakes are considered as natural reservoirs of excess recharge and good flood regulators in the lower parts of river basins. Due to specific ecohydrological processes and environmental conditions, these areas host unique wetland ecosystems with high levels of biodiversity and provide various ecosystem services, such as ecological productivity, photosynthesis and carbon storage. Given the dynamic nature of hydrological processes in karst aquifers, a distinctive feature of the phenomena described is its high variability of occurrence and duration. Therefore, the identification, characterization as well as the determination of the spatial dimension of flood levels is a challenging task. Focusing on the Slovenian karst, a literature review and analysis of topographical and hydrological data of the selected study areas was conducted. The hydrological analyses were based on long-term monitoring data from Slovenian Environmental Agency and partly on the authors' own database of field measurements and knowledge of the areas concerned. Consequently, the conceptual framework and the key criterion for the determination and recording of areas subject to temporary flooding were developed. A systematic survey reveals the significance of the extent, duration and frequency of flooding. Evaluation results are useful to designers of various water policies and management mechanisms for flood mitigation and protection of special habitats. Observing trends in the spatial and temporal dynamics of flood levels is also valuable for understanding how and to what extent karst aquifers are vulnerable to environmental changes. Finally, the analyses also enable prediction of the effects of these changes on other parts of the environment (e.g., hydrophilic habitats).</p>

scholarly journals Temporal Dynamics of the Gut Bacteriome and Mycobiome in the Weanling Pig

2020 ◽  
Vol 8 (6) ◽  
pp. 868
Author(s):  
Ann M. Arfken ◽  
Juli Foster Frey ◽  
Katie Lynn Summers
Keyword(s):  
Environmental Changes ◽  
Temporal Dynamics ◽  
Network Connectivity ◽  
Longitudinal Assessment ◽  
Swine Industry ◽  
Colonization Dynamics ◽  
Dramatic Shift ◽  
Two Kingdoms ◽  
Single Time Point ◽  
Over Time

Weaning is a period of environmental changes and stress that results in significant alterations to the piglet gut microbiome and is associated with a predisposition to disease, making potential interventions of interest to the swine industry. In other animals, interactions between the bacteriome and mycobiome can result in altered nutrient absorption and susceptibility to disease, but these interactions remain poorly understood in pigs. Recently, we assessed the colonization dynamics of fungi and bacteria in the gastrointestinal tract of piglets at a single time point post-weaning (day 35) and inferred interactions were found between fungal and bacterial members of the porcine gut ecosystem. In this study, we performed a longitudinal assessment of the fecal bacteriome and mycobiome of piglets from birth through the weaning transition. Piglet feces in this study showed a dramatic shift over time in the bacterial and fungal communities, as well as an increase in network connectivity between the two kingdoms. The piglet fecal bacteriome showed a relatively stable and predictable pattern of development from Bacteroidaceae to Prevotellaceae, as seen in other studies, while the mycobiome demonstrated a loss in diversity over time with a post-weaning population dominated by Saccharomycetaceae. The mycobiome demonstrated a more transient community that is likely driven by factors such as diet or environmental exposure rather than an organized pattern of colonization and succession evidenced by fecal sample taxonomic clustering with nursey feed samples post-weaning. Due to the potential tractability of the community, the mycobiome may be a viable candidate for potential microbial interventions that will alter piglet health and growth during the weaning transition.

scholarly journals Mapping evaporative water loss in desert passerines reveals an expanding threat of lethal dehydration

2017 ◽  
Vol 114 (9) ◽  
pp. 2283-2288 ◽  
Author(s):  
Thomas P. Albright ◽  
Denis Mutiibwa ◽  
Alexander. R. Gerson ◽  
Eric Krabbe Smith ◽  
William A. Talbot ◽  
...  
Keyword(s):  
Water Loss ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Heat Waves ◽  
Arid Zone ◽  
Evaporative Water Loss ◽  
Physiological Data ◽  
Passerine Birds ◽  
Evaporative Water ◽  
Thermal Refugia

Extreme high environmental temperatures produce a variety of consequences for wildlife, including mass die-offs. Heat waves are increasing in frequency, intensity, and extent, and are projected to increase further under climate change. However, the spatial and temporal dynamics of die-off risk are poorly understood. Here, we examine the effects of heat waves on evaporative water loss (EWL) and survival in five desert passerine birds across the southwestern United States using a combination of physiological data, mechanistically informed models, and hourly geospatial temperature data. We ask how rates of EWL vary with temperature across species; how frequently, over what areas, and how rapidly lethal dehydration occurs; how EWL and die-off risk vary with body mass; and how die-off risk is affected by climate warming. We find that smaller-bodied passerines are subject to higher rates of mass-specific EWL than larger-bodied counterparts and thus encounter potentially lethal conditions much more frequently, over shorter daily intervals, and over larger geographic areas. Warming by 4 °C greatly expands the extent, frequency, and intensity of dehydration risk, and introduces new threats for larger passerine birds, particularly those with limited geographic ranges. Our models reveal that increasing air temperatures and heat wave occurrence will potentially have important impacts on the water balance, daily activity, and geographic distribution of arid-zone birds. Impacts may be exacerbated by chronic effects and interactions with other environmental changes. This work underscores the importance of acute risks of high temperatures, particularly for small-bodied species, and suggests conservation of thermal refugia and water sources.

scholarly journals Testing interactive effects of global environmental changes on soil nitrogen cycling

Ecosphere ◽  
2011 ◽  
Vol 2 (5) ◽  
pp. art56 ◽  
Author(s):  
A. Niboyet ◽  
X. Le Roux ◽  
P. Dijkstra ◽  
B. A. Hungate ◽  
L. Barthes ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Soil Nitrogen ◽  
Environmental Changes ◽  
Interactive Effects ◽  
Global Environmental ◽  
Soil Nitrogen Cycling ◽  
Global Environmental Changes

scholarly journals Cross-modal object recognition and dynamic weighting of sensory inputs in a fish

2016 ◽  
Vol 113 (27) ◽  
pp. 7638-7643 ◽  
Author(s):  
Sarah Schumacher ◽  
Theresa Burt de Perera ◽  
Johanna Thenert ◽  
Gerhard von der Emde
Keyword(s):  
Object Recognition ◽  
Environmental Changes ◽  
Mammalian Species ◽  
Brain Structures ◽  
Weakly Electric Fish ◽  
Mammalian Brain ◽  
Sensory Inputs ◽  
Level Function ◽  
Dynamic Weighting ◽  
High Level

Most animals use multiple sensory modalities to obtain information about objects in their environment. There is a clear adaptive advantage to being able to recognize objects cross-modally and spontaneously (without prior training with the sense being tested) as this increases the flexibility of a multisensory system, allowing an animal to perceive its world more accurately and react to environmental changes more rapidly. So far, spontaneous cross-modal object recognition has only been shown in a few mammalian species, raising the question as to whether such a high-level function may be associated with complex mammalian brain structures, and therefore absent in animals lacking a cerebral cortex. Here we use an object-discrimination paradigm based on operant conditioning to show, for the first time to our knowledge, that a nonmammalian vertebrate, the weakly electric fish Gnathonemus petersii, is capable of performing spontaneous cross-modal object recognition and that the sensory inputs are weighted dynamically during this task. We found that fish trained to discriminate between two objects with either vision or the active electric sense, were subsequently able to accomplish the task using only the untrained sense. Furthermore we show that cross-modal object recognition is influenced by a dynamic weighting of the sensory inputs. The fish weight object-related sensory inputs according to their reliability, to minimize uncertainty and to enable an optimal integration of the senses. Our results show that spontaneous cross-modal object recognition and dynamic weighting of sensory inputs are present in a nonmammalian vertebrate.

scholarly journals Press xenobiotic disturbance favors deterministic assembly with a shift in function and structure of bacterial communities in sludge bioreactors

2020 ◽  
Author(s):  
Ezequiel Santillan ◽  
Hari Seshan ◽  
Stefan Wuertz
Keyword(s):  
Community Structure ◽  
Bacterial Communities ◽  
Temporal Dynamics ◽  
Treatment Plant ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Batch Reactors ◽  
Function Structure ◽  
Community Function ◽  
And Function

AbstractDisturbance is thought to affect community assembly mechanisms, which in turn shape community structure and the overall function of the ecosystem. Here, we tested the effect of a continuous (press) xenobiotic disturbance on the function, structure, and assembly of bacterial communities within a wastewater treatment system. Two sets of four-liter sequencing batch reactors were operated in triplicate with and without the addition of 3-chloroaniline for a period of 132 days, following 58 days of acclimation after inoculation with sludge from a full-scale treatment plant. Temporal dynamics of bacterial community structure were derived from 16S rRNA gene amplicon sequencing. Community function, structure and assembly differed between press disturbed and undisturbed reactors. Temporal partitioning of assembly mechanisms via phylogenetic and non-phylogenetic null modelling analysis revealed that deterministic assembly prevailed for disturbed bioreactors, while the role of stochastic assembly was stronger for undisturbed reactors. Our findings are relevant because research spanning various disturbance types, environments and spatiotemporal scales is needed for a comprehensive understanding of the effects of press disturbances on assembly mechanisms, structure, and function of microbial communities.Graphical abstract

scholarly journals Spatio-Temporal Dynamics of Landuse/Land Cover Around NTPC Using High Resolution Satellite Imagery

2020 ◽  
pp. 101-109
Keyword(s):  
Rapid Growth ◽  
Agricultural Land ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Geographical Area ◽  
Considerable Change ◽  
Central Component ◽  
Land Resource ◽  
Spatio Temporal ◽  
Level I

Land is becoming scarce resource due to population growth and industrialization. Rapid growth of human activities can also be attributed as one of the reasons. Thus, it becomes an important task to regulate land resource for sustainable development and environmental protection. LULC change studies have become a central component in current strategies for managing and planning land resources and monitoring environmental changes. In this paper an attempt has been made to bring out spatio-temporal dynamics of LULC patterns of NTPCRamagundam and its surrounding environment by using multi-temporal satellite data of Landsat-4, IRS P6 LISS-III and IRS 2 LISS-IV and GIS techniques for the years 1984, 2005, 2011, 2015, 2018. The methodology includes base map preparation having features like Road (SH), Rail, Canal, River, Stream, Tanks, Forest boundary and other administrative boundaries from SOI topo sheet and the features digitized are updated on satellite images. Interpretation of study area for LULC feature extraction on satellite imageries of respective years is carried with Nrsc’s standard LULC classification system. Change detection statistics can be generated out of 5 LULC thematic layers obtained and analysed specially with respect to NTPC environs. Results from this study shows the percentage of geographical area occupied by built-up land, agricultural land, forests, wasteland and waterbodies of level-I LULC features were 10.27%, 60.68%, 6.61%, 11.81%, 10.63% respectively in 1984 and were changed into 21.41%, 48.51%, 5.97%, 12.77%, 11.34% respectively in 2018. This analysis shows a rapid growth in built-up land and fall in agricultural land between 1984 and 2018. There is a considerable change in the remaining features from 1984 and 2018.

scholarly journals Sources and Transformations of Nitrogen in Urban Landscapes

EDIS ◽  
2020 ◽  
Vol 2020 (2) ◽  
Author(s):  
Alexander Joseph Reisinger ◽  
Mary Lusk ◽  
Ashley Smyth
Keyword(s):  
Water Quality ◽  
Nitrogen Cycling ◽  
Nitrogen Cycle ◽  
Urban Environments ◽  
Nutrient Pollution ◽  
Urban Landscapes ◽  
Aquatic Resources ◽  
Quality Issues ◽  
Soil And Water

With 80% of Florida’s residents living within 10 miles of the coast, Florida’s aquatic resources are directly affected by urbanization. The intent of this new 6-page publication of the UF/IFAS Department of Soil and Water Sciences is to describe the urban nitrogen cycle for a non-technical audience. Ultimately, this document is intended for individuals working in urban environments and concerned about nutrient pollution and water quality issues, but do not have a technical background and want to improve their understanding of nitrogen cycling. Written by Alexander J. Reisinger, Mary G. Lusk, and Ashley R. Smyth. https://edis.ifas.ufl.edu/ss681

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