scholarly journals Soil microbial inoculation during flood events shapes headwater stream microbial communities and diversity

2021 ◽  
Author(s):  
Florian Caillon ◽  
Katharina Besemer ◽  
Peter Peduzzi ◽  
Jakob Schelker
Keyword(s):  
Microbial Diversity ◽  
Bacterial Diversity ◽  
Soil Water ◽  
Headwater Streams ◽  
High Flow ◽  
Low Flow ◽  
Flood Events ◽  
Flow Conditions ◽  
Soil Microbial ◽  
Microbial Inoculation

AbstractFlood events are now recognized as potentially important occasions for the transfer of soil microbes to stream ecosystems. Yet, little is known about these “dynamic pulses of microbial life” for stream bacterial community composition (BCC) and diversity. In this study, we explored the potential alteration of stream BCC by soil inoculation during high flow events in six pre-alpine first order streams and the larger Oberer Seebach. During 1 year, we compared variations of BCC in soil water, stream water and in benthic biofilms at different flow conditions (low to intermediate flows versus high flow). Bacterial diversity was lowest in biofilms, followed by soils and highest in headwater streams and the Oberer Seebach. In headwater streams, bacterial diversity was significantly higher during high flow, as compared to low flow (Shannon diversity: 7.6 versus 7.9 at low versus high flow, respectively, p < 0.001). Approximately 70% of the bacterial operational taxonomic units (OTUs) from streams and stream biofilms were the same as in soil water, while in the latter one third of the OTUs were specific to high flow conditions. These soil high-flow OTUs were also found in streams and biofilms at other times of the year. These results demonstrate the relevance of floods in generating short and reoccurring inoculation events for flowing waters. Moreover, they show that soil microbial inoculation during high flow enhances microbial diversity and shapes fluvial BCC even during low flow. Hence, soil microbial inoculation during floods could act as a previously overlooked driver of microbial diversity in headwater streams.

scholarly journals Plant Taxonomic Diversity Better Explains Soil Fungal and Bacterial Diversity than Functional Diversity in Restored Forest Ecosystems

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 479 ◽  
Author(s):  
Hanif ◽  
Guo ◽  
Moniruzzaman ◽  
He ◽  
Yu ◽  
...  
Keyword(s):  
Species Richness ◽  
Microbial Diversity ◽  
Soil Properties ◽  
Bacterial Diversity ◽  
Functional Diversity ◽  
Forest Ecosystems ◽  
Taxonomic Diversity ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Bacterial Richness

Plant attributes have direct and indirect effects on soil microbes via plant inputs and plant-mediated soil changes. However, whether plant taxonomic and functional diversities can explain the soil microbial diversity of restored forest ecosystems remains elusive. Here, we tested the linkage between plant attributes and soil microbial communities in four restored forests (Acacia species, Eucalyptus species, mixed coniferous species, mixed native species). The trait-based approaches were applied for plant properties and high-throughput Illumina sequencing was applied for fungal and bacterial diversity. The total number of soil microbial operational taxonomic units (OTUs) varied among the four forests. The highest richness of fungal OTUs was found in the Acacia forest. However, bacterial OTUs were highest in the Eucalyptus forest. Species richness was positively and significantly related to fungal and bacterial richness. Plant taxonomic diversity (species richness and species diversity) explained more of the soil microbial diversity than the functional diversity and soil properties. Prediction of fungal richness was better than that of bacterial richness. In addition, root traits explained more variation than the leaf traits. Overall, plant taxonomic diversity played a more important role than plant functional diversity and soil properties in shaping the soil microbial diversity of the four forests.

scholarly journals Remodeling of Resistance Arteries in Renal Failure: Effect of Endothelin Receptor Blockade

2001 ◽  
Vol 12 (10) ◽  
pp. 2040-2050 ◽  
Author(s):  
KERSTIN AMANN ◽  
GABRIEL MIL TENBERGER-MIL TENYI ◽  
AURELIA SIMONOVICIENE ◽  
ANDREAS KOCH ◽  
STEPHAN ORTH ◽  
...  
Keyword(s):  
Renal Failure ◽  
Blood Flow ◽  
High Flow ◽  
Mesenteric Arteries ◽  
Low Flow ◽  
Normal Flow ◽  
Flow Conditions ◽  
First Order ◽  
The Media ◽  
Intimal Thickness

Abstract. Remodeling of vessels is a known feature of renal failure, but it is unclear whether this represents an appropriate or inappropriate response to the known changes in blood flow, shear stress, and wall tension. To investigate remodeling in response to variations in blood flow, first-order mesenteric arteries were exposed to high- and low-flow conditions via the ligation of second-order branches, according to the technique described by Pour-ageaud and De Mey. The resulting changes in vessel geometric features, relative proportions of intima and media, submicroscopic structure, and immunostaining for proliferating cell nuclear antigen (PCNA), endothelin-1 (ET-1), and ETAreceptors were assessed in first-order mesenteric arteries under low-flow and high-flow conditions. Subtotally nephrectomized (SNX) animals were compared with sham-operated rats. Animals either were left untreated or were treated with the ETAreceptor antagonist (ET-RA) LU-135252, because of suggestions in the literature that ET is involved in vascular remodeling in uremia. A highly significant increase in intimal thickness was noted in low-flow arteries (4.21 ± 1.39 μm) of SNX animals, compared with normal-flow arteries (2.06 ± 0.61 μm), but this increase was not observed in sham-operated rats (1.38 ± 0.77 in low-flow arteriesversus2.40 ± 0.35 μm in normal-flow arteries). The increase in intimal thickness in low-flow arteries was abrogated by ET-RA. The medial thickness was increased in untreated SNX animals (19.5 ± 3.61 μm), compared with sham-operated rats, and this increase was also prevented by ET-RA. The medial thickness was not affected by low flow in either sham-operated or SNX animals. In parallel, the number of PCNA-positive intimal cells was higher in low-flow, but not high-flow, arteries of SNX rats, compared with sham-operated rats. No significant change was observed in sham-operated animals. In the media, the number of PCNA-positive cells was higher in untreated SNX animals than in sham-operated rats. The number was even more markedly increased in high-flow, but not low-flow, vessels. This increase was abrogated by ET-RA. It is concluded that, in uremic animals, the response of the intima to low flow and the response of the media to high flow are exaggerated. Both responses are apparently mediated by ET.

scholarly journals Transit times from rainfall to baseflow in headwater catchments estimated using tritium: the Ovens River, Australia

2015 ◽  
Vol 19 (9) ◽  
pp. 3771-3785 ◽  
Author(s):  
I. Cartwright ◽  
U. Morgenstern
Keyword(s):  
Transit Time ◽  
Headwater Streams ◽  
Stream Water ◽  
Mean Transit Time ◽  
Significant Proportion ◽  
Low Flow ◽  
Flow Conditions ◽  
Headwater Catchments ◽  
Flow Models ◽  
Transit Times

Abstract. Headwater streams contribute a significant proportion of the total flow to many river systems, especially during summer low-flow periods. However, despite their importance, the time taken for water to travel through headwater catchments and into the streams (the transit time) is poorly understood. Here, 3H activities of stream water are used to define transit times of water contributing to streams from the upper reaches of the Ovens River in south-east Australia at varying flow conditions. 3H activities of the stream water varied from 1.63 to 2.45 TU, which are below the average 3H activity of modern local rainfall (2.85 to 2.99 TU). The highest 3H activities were recorded following higher winter flows and the lowest 3H activities were recorded at summer low-flow conditions. Variations of major ion concentrations and 3H activities with streamflow imply that different stores of water from within the catchment (e.g. from the soil or regolith) are mobilised during rainfall events rather than there being simple dilution of an older groundwater component by event water. Mean transit times calculated using an exponential-piston flow model range from 4 to 30 years and are higher at summer low-flow conditions. Mean transit times calculated using other flow models (e.g. exponential flow or dispersion) are similar. There are broad correlations between 3H activities and the percentage of rainfall exported from each catchment and between 3H activities and Na and Cl concentrations that allow first-order estimates of mean transit times in adjacent catchments or at different times in these catchments to be made. Water from the upper Ovens River has similar mean transit times to the headwater streams implying there is no significant input of old water from the alluvial gravels. The observation that the water contributing to the headwater streams in the Ovens catchment has a mean transit time of years to decades implies that these streams are buffered against rainfall variations on timescales of a few years. However, impacts of any changes to land use in these catchments may take years to decades to manifest themselves in changes to streamflow or water quality.

scholarly journals Transit times from rainfall to baseflow in headwater catchments estimated using tritium: the Ovens River, Australia

2015 ◽  
Vol 12 (6) ◽  
pp. 5427-5463 ◽  
Author(s):  
I. Cartwright ◽  
U. Morgenstern
Keyword(s):  
Transit Time ◽  
Headwater Streams ◽  
Stream Water ◽  
Mean Transit Time ◽  
Significant Proportion ◽  
Low Flow ◽  
Flow Conditions ◽  
Headwater Catchments ◽  
Flow Models ◽  
Transit Times

Abstract. Headwater streams contribute a significant proportion of the total flow to many river systems, especially during summer low-flow periods. However, despite their importance, the time taken for water to travel through headwater catchments and into the streams (the transit time) is poorly constrained. Here, 3H activities of stream water are used to define transit times of water contributing to streams from the upper reaches of the Ovens River in southeast Australia at varying flow conditions. 3H activities of the stream water varied from 1.63 to 2.45 TU, which are below the average 3H activity of modern local rainfall (~3 TU). The highest 3H activities were recorded following higher winter flows and the lowest 3H activities were recorded at summer low-flow conditions. Variations of major ion concentrations and 3H activities with streamflow imply that different stores of water from within the catchment (e.g. from the soil or regolith) are mobilised during rainfall events rather than there being simple dilution of an older groundwater component by event water. Mean transit times calculated using an exponential-piston flow model range between 5 and 31 years and are higher at summer low-flow conditions. Mean transit times calculated using other flow models (e.g. exponential flow or dispersion) are similar. There are broad correlations between 3H activities and the percentage of rainfall exported from each catchment and between 3H activities and Na and Cl concentrations that allow first-order estimates of mean transit times in adjacent catchments or at different times in these catchments to be made. Water from the upper Ovens River has similar mean transit times to the headwater streams implying there is no significant input of old water from the alluvial gravels. The observation that the water contributing to the headwater streams in the Ovens catchment has a mean transit time of years to decades implies that these streams are buffered against rainfall variations on timescales of a few years. However, impacts of any changes to landuse in these catchments may take years to decades to manifest itself in changes to streamflow or water quality.

scholarly journals Longitudinal scattering coefficient obtained by hydroacoustic measurement and by conservative tracer

2021 ◽  
pp. 75-86
Author(s):  
Ana F. Nadal ◽  
José M. Díaz Lozada ◽  
Gonzalo P. Barbero Medina ◽  
Karen M. Moro ◽  
Mariana N. Melchiorre ◽  
...  
Keyword(s):  
Dispersion Coefficient ◽  
Flow Characteristics ◽  
Chemical Reactor ◽  
High Flow ◽  
Low Flow ◽  
Flow Conditions ◽  
Dry Period ◽  
Longitudinal Dispersion Coefficient ◽  
Transport Models ◽  
Conservative Tracer

The objective of the present work was to determine the value of the longitudinal dispersion coefficient (DL) of the Chicamtoltina stream (Alta Gracia) by means of two different techniques, in order to compare the values obtained. The first technique consisted of applying a developed formula that includes a detailed description of hydrodynamic parameters obtained by gauging with a hydroacoustic instrument, while the second technique consisted of injecting a conservative tracer, using the same approach as the non-ideal chemical reactor theory of flow with dispersion. This work was carried out at low flow conditions (dry period) and at high flow conditions (wet period). It was found that, either for high flow or low flow, the values of the dispersion coefficient obtained by both techniques have good agreement, fitting better in the dry period than in the wet period. Due to the fact that frequent gauging campaigns are carried out in this stream, it is concluded that with similar flow characteristics and morphology of the section, the gauging data can be used to determine the DL coefficient, in order to incorporate reliable data that can be applied to pollutant transport models.

Estimating river water-quality trends under different flow conditions

2021 ◽  
Author(s):  
Qian Zhang ◽  
James Webber ◽  
Douglas Moyer ◽  
Jeffrey Chanat
Keyword(s):  
Water Quality ◽  
River Water ◽  
Total Nitrogen ◽  
Nitrogen Concentration ◽  
High Flow ◽  
River Water Quality ◽  
Low Flow ◽  
Flow Conditions ◽  
Particulate Nitrogen ◽  
Water Quality Trends

&lt;p&gt;A number of statistical approaches have been developed to quantify the overall trend in river water quality, but most approaches are not intended for reporting separate trends for different flow conditions. We propose an approach called FN&lt;sub&gt;2Q&lt;/sub&gt;, which is an extension of the flow-normalization (FN) procedure of the well-established WRTDS (&amp;#8220;Weighted Regressions on Time, Discharge, and Season&amp;#8221;) method. The FN&lt;sub&gt;2Q&lt;/sub&gt;&amp;#160;approach provides a daily time series of low-flow and high-flow FN flux estimates that represent the lower and upper half of daily riverflow observations that occurred on each calendar day across the period of record. These daily estimates can be summarized into any time period of interest (e.g., monthly, seasonal, or annual) for quantifying trends. The proposed approach is illustrated with an application to a record of total nitrogen concentration (632 samples) collected between 1985 and 2018 from the South Fork Shenandoah River at Front Royal, Virginia (USA). Results show that the overall FN flux of total nitrogen has declined in the period of 1985&amp;#8211;2018, which is mainly attributable to FN flux decline in the low-flow class. Furthermore, the decline in the low-flow class was highly correlated with wastewater effluent loads, indicating that the upgrades of treatment technology at wastewater treatment facilities have likely led to water-quality improvement under low-flow conditions. The high-flow FN flux showed a spike around 2007, which was likely caused by increased delivery of particulate nitrogen associated with sediment transport. The case study demonstrates the utility of the FN&lt;sub&gt;2Q&lt;/sub&gt;&amp;#160;approach toward not only characterizing the changes in river water quality but also guiding the direction of additional analysis for capturing the underlying drivers. The FN&lt;sub&gt;2Q&lt;/sub&gt; approach (and the published code) can easily be applied to widely available river monitoring records to quantify water-quality trends under different flow conditions to enhance understanding of river water-quality dynamics. &lt;span&gt;(Journal article: https://doi.org/10.1016/j.scitotenv.2020.143562; R code and data release: https://doi.org/10.5066/P9LBJEY1).&lt;/span&gt;&lt;/p&gt;

Characteristics of sediments in a newly constructed reservoir in Japan

2006 ◽  
Vol 53 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Y. Sakurai ◽  
S. Haruta
Keyword(s):  
High Flow ◽  
Low Flow ◽  
Particulate Phosphorus ◽  
Formation Mechanisms ◽  
Flow Conditions ◽  
Discharge Rates ◽  
Main River ◽  
Sediment Formation ◽  
Specific Discharge ◽  
Land Surfaces

The sediment formation mechanisms of a newly constructed reservoir in Ehime, Japan were evaluated by characterizing the soil particles (SP) and particulate phosphorus (PP) in the runoff and reservoir sediments. The SP and PP loads from the runoffs of the main river in the watershed considerably increased, when the specific discharge rates were over 300 l/s/km2 (high flow conditions). When the specific discharge rates exceeded over 300 l/s/km2, 19% of the watershed generated over 80% of the SP and PP loads. When the specific discharge rates were under 300 l/s/km2 (low flow conditions), the contributions of the previously mentioned 19% area to the SP and PP loads were smaller. Significant amounts of smectite were found in the sediments in the reservoir and in the soil samples obtained at the forest exposed area in this 19% area while it was negligible in citrus orchards and paddy fields that constituted the remaining land surfaces. The forest area exposed by recent landslides was significant for the SP and PP in the reservoir. Judging from the outcomes, land use information alone may not be sufficient to detect critical sources of SP and PP in the runoffs and reservoirs. To identify and confirm crucial areas for the SP and PP in the runoffs, the investigations should be conducted under high flow conditions and the composition of clay minerals in the sediments should be checked against the clay mineral distributions of soils in the watershed.

Soil microbial biomass and diversity after herbicide application

2004 ◽  
Vol 84 (2) ◽  
pp. 677-685 ◽  
Author(s):  
N. Z. Lupwayi ◽  
K. N. Harker ◽  
G. W. Clayton ◽  
T. K. Turkington ◽  
W. A. Rice ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Biomass ◽  
Microbial Diversity ◽  
Bacterial Diversity ◽  
Field Experiments ◽  
Greenhouse Experiment ◽  
Glufosinate Ammonium ◽  
Chernozemic Soil ◽  
Soil Microbial ◽  
Microbial C

Greenhouse and field experiments were conducted to investigate the effects of herbicides on soil microbial C (microbial biomass), bacterial diversity and community structure. In the first greenhouse experiment, 12 herbicides were applied at recommended rates to a Gray Luvisolic soil contained in trays. Soil samples were collected 0, 1, 2, 3 and 4 wk after treatment and analysed for microbial C and bacterial diversity. The second greenhouse experiment was similar to the first, but only 6 of the 12 herbicides were applied to a Gray Luvisolic and Black Chernozemic soil. The same six herbicides were applied to the Gray Luvisolic soil at a field site near Fort Vermilion, Alberta, and to the Black Chernozemic soil at Lacombe, Alberta, in 2000. In the first greenhouse experiment, metribuzin, imazamox/imazethapyr, triasulfuron and metsulfuron methyl reduced microbial C compared with glufosinate ammonium and sethoxydim. In the second greenhouse experiment, microbial diversity as determined by Shannon index was lower after application of metribuzin, imazamox/imazethapyr and glufosinate ammonium than after application of glyphosate, but none of the herbicides altered microbial diversity relative to the control treatment. In the field experiments, herbicides had no effect on microbial C or diversity. In all experiments, examination of microbial community structure revealed herbicide-induced shifts in microbial composition even when diversity indices among treatments were not different. It was concluded that herbicides applied once at recommended rates did not have significant or consistent effects on microbial C or diversity. Key words: Environmental sustainability, substrate utilization, biological soil quality, community-level physiological profiles (CLPP)

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