Long-Term Record of Nutrient Concentrations in Kāne‘ohe Bay, O‘ahu, Hawai‘i, and Its Relevance to Onset and End of a Phase Shift Involving an Indigenous Alga, Dictyosphaeria cavernosa

2015 ◽  
Vol 69 (3) ◽  
pp. 319-339 ◽  
Author(s):  
John Stimson
Keyword(s):  
Phase Shift ◽  
Nutrient Concentrations ◽  
Dictyosphaeria Cavernosa

scholarly journals Bacterial Communities and Enzymatic Activities in Sediments of Long-Term Fish and Crab Aquaculture Ponds

2021 ◽  
Vol 9 (3) ◽  
pp. 501
Author(s):  
Zhimin Zhang ◽  
Qinghui Deng ◽  
Lingling Wan ◽  
Xiuyun Cao ◽  
Yiyong Zhou ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Enzymatic Activities ◽  
Nutrient Concentrations ◽  
Biological Processes ◽  
Farming Practices ◽  
Mitten Crab ◽  
Aquaculture Ponds ◽  
Pond Sediments ◽  
Sediment Ph

Aquaculture is among the most important and fastest growing agriculture sectors worldwide; however, it generates environmental impacts by introducing nutrient accumulations in ponds, which are possibly different and further result in complex biological processes in the sediments based on diverse farming practices. In this study, we investigated the effects of long-term farming practices of representative aquatic animals dominated by grass carp (GC, Ctenopharyngodon idella) or Chinese mitten crab (CMC, Eriocheir sinensis) on the bacterial community and enzyme activity of sediments from more than 15 years of aquaculture ponds, and the differences associated with sediment properties were explored in the two farming practices. Compared to CMC ponds, GC ponds had lower contents of TC, TN, and TP in sediments, and similar trends for sediment pH and moisture content. Sediment bacterial communities were significantly different between GC and CMC ponds, with higher bacterial richness and diversity in GC ponds. The bacterial communities among the pond sediments were closely associated with sediment pH, TC, and TN. Additionally, the results showed profoundly lower activities of β-1,4-glucosidase, leucine aminopeptidase, and phosphatase in the sediments of GC ponds than CMC ponds. Pearson’s correlation analysis further revealed strong positive correlations between the hydrolytic enzyme activities and nutrient concentrations among the aquaculture ponds, indicating microbial enzyme regulation response to sediment nutrient dynamics. Our study herein reveals that farming practices of fish and crab differently affect bacterial communities and enzymatic activities in pond sediments, suggesting nutrient-driven sediment biological processes in aquaculture ponds for different farming practices.

Nutrient cycling differs between cropped soils with century-old and recently pyrolyzed biochar

2021 ◽  
Author(s):  
Victor Burgeon ◽  
Julien Fouché ◽  
Sarah Garré ◽  
Ramin Heidarian-Dehkordi ◽  
Gilles Colinet ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Soil Solution ◽  
Nutrient Dynamics ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Nutrient Concentrations ◽  
Soil Productivity ◽  
Long Term Effects ◽  
Mitigation And Adaptation

<p>The amendment of biochar to soils is often considered for its potential as a climate change mitigation and adaptation tool through agriculture. Its presence in tropical agroecosystems has been reported to positively impact soil productivity whilst successfully storing C on the short and long-term. In temperate systems, recent research showed limited to no effect on productivity following recent biochar addition to soils. Its long-term effects on productivity and nutrient cycling have, however, been overlooked yet are essential before the use of biochar can be generalized.</p><p>Our study was set up in a conventionally cropped field, containing relict charcoal kiln sites used as a model for century old biochar (CoBC, ~220 years old). These sites were compared to soils amended with recently pyrolyzed biochar (YBC) and biochar free soils (REF) to study nutrient dynamics in the soil-water-plant system. Our research focused on soil chemical properties, crop nutrient uptake and soil solution nutrient concentrations. Crop plant samples were collected over three consecutive land occupations (chicory, winter wheat and a cover crop) and soil solutions gathered through the use of suctions cups inserted in different horizons of the studied Luvisol throughout the field.</p><p>Our results showed that YBC mainly influenced the soil solution composition whereas CoBC mainly impacted the total and plant available soil nutrient content. In soils with YBC, our results showed lower nitrate and potassium concentrations in subsoil horizons, suggesting a decreased leaching, and higher phosphate concentrations in topsoil horizons. With time and the oxidation of biochar particles, our results reported higher total soil N, available K and Ca in the topsoil horizon when compared to REF, whereas available P was significantly smaller. Although significant changes occurred in terms of plant available nutrient contents and soil solution nutrient concentrations, this did not transcend in variations in crop productivity between soils for neither of the studied crops. Overall, our study highlights that young or aged biochar behave as two distinct products in terms of nutrient cycling in soils. As such the sustainability of these soils differ and their management must therefore evolve with time.</p>

scholarly journals Proteomic Analysis of Stationary Phase in the Marine Bacterium “Candidatus Pelagibacter ubique”

2008 ◽  
Vol 74 (13) ◽  
pp. 4091-4100 ◽  
Author(s):  
Sarah M. Sowell ◽  
Angela D. Norbeck ◽  
Mary S. Lipton ◽  
Carrie D. Nicora ◽  
Stephen J. Callister ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Thioredoxin Reductase ◽  
Capillary Liquid Chromatography ◽  
Nutrient Concentrations ◽  
Ambient Conditions ◽  
Term Survival ◽  
Protein Encoding ◽  
Quantitative Examination ◽  
Candidatus Pelagibacter Ubique

ABSTRACT “Candidatus Pelagibacter ubique,” an abundant marine alphaproteobacterium, subsists in nature at low ambient nutrient concentrations and may often be exposed to nutrient limitation, but its genome reveals no evidence of global regulatory mechanisms for adaptation to stationary phase. High-resolution capillary liquid chromatography coupled online to an LTQ mass spectrometer was used to build an accurate mass and time (AMT) tag library that enabled quantitative examination of proteomic differences between exponential- and stationary-phase “Ca. Pelagibacter ubique” cells cultivated in a seawater medium. The AMT tag library represented 65% of the predicted protein-encoding genes. “Ca. Pelagibacter ubique” appears to respond adaptively to stationary phase by increasing the abundance of a suite of proteins that contribute to homeostasis rather than undergoing a major remodeling of its proteome. Stationary-phase abundances increased significantly for OsmC and thioredoxin reductase, which may mitigate oxidative damage in “Ca. Pelagibacter,” as well as for molecular chaperones, enzymes involved in methionine and cysteine biosynthesis, proteins involved in ρ-dependent transcription termination, and the signal transduction enzyme CheY-FisH. We speculate that this limited response may enable “Ca. Pelagibacter ubique” to cope with ambient conditions that deprive it of nutrients for short periods and, furthermore, that the ability to resume growth overrides the need for a more comprehensive global stationary-phase response to create a capacity for long-term survival.

Long-term organic and conventional farming effects on nutrient density of oats

2021 ◽  
pp. 1-15
Author(s):  
Emmanuel Chiwo Omondi ◽  
Marisa Wagner ◽  
Atanu Mukherjee ◽  
Kristine Nichols
Keyword(s):  
Amino Acids ◽  
Cropping Systems ◽  
Vitamin B1 ◽  
Essential Amino Acids ◽  
Total Carbon ◽  
Nutrient Concentrations ◽  
Amino Acid Synthesis ◽  
Organic Systems ◽  
Nutrient Density

Abstract Declining nutrient densities of crops in the past 50–70 years have been attributed to unsound agricultural practices and plant breeding focus on yield rather than quality. Few studies have quantified the soil and nutritional quality of grains in organic and conventional farms and reported results are scarce and inconsistent. The Rodale Institute's Farming Systems Trial (FST) was established in 1981 to quantify the effects of long-term organic and conventional grain cropping systems and tillage practices. A 2014 study to quantify effects on the nutrient density of oat grains was integrated into three systems within the long-term trial: organic manure-based (MNR), organic legume-based (LEG), and conventional synthetic input-based (CNV), split between tilled (T) and no-till (NT) practices. Oat grains with hulls removed were analyzed for minerals (n = 24), vitamins (n = 24), amino acids (n = 24) and proteins (n = 24), while soil samples to a depth of 10 cm were analyzed for elemental minerals, and total carbon (C), nitrogen (N) and sulfur (S). Organic systems increased six out ten soil minerals whose concentrations were influenced by cropping systems: aluminum (Al), iron (Fe), chromium (Cr), calcium (Ca), barium (B) and strontium (Sr). All essential amino acids were greater in oat grains under LEG systems compared with other systems except lysine, histidine and methionine. Both LEG systems also increased 12 out of 13 non-essential amino acids in oat grains. Total oat N, C and S required for amino acid synthesis tended to be greater in organic systems. Soil N, C and S were highly correlated with total oat amino acids under organic systems compared to CNV. Organic LEG had significantly greater vitamin B1 than MNR and CNV. These results suggest that nutrient concentrations of oat grains were greater in organic systems compared to CNV systems, and the increase could be partially explained by the long-term soil management differences between the systems.

scholarly journals Effects of Load Reductions on Phosphorus Concentrations in a Baltic Estuary—Long-Term Changes, Seasonal Variation, and Management Implications

2020 ◽  
Vol 44 (1) ◽  
pp. 30-43
Author(s):  
Jakob Walve ◽  
Maria Sandberg ◽  
Ragnar Elmgren ◽  
Christer Lännergren ◽  
Ulf Larsson
Keyword(s):  
Surface Water ◽  
Spring Bloom ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
P Concentration ◽  
Source Contributions ◽  
A Minor ◽  
Autumn And Winter

AbstractNutrient concentrations in coastal waters are influenced not only by land runoff, point sources, and water exchange with the sea but are also modified by settlement to and release from sediments. This complicates evaluation of measures to reduce nutrient loads. We used a mass-balance box model to calculate long-term (1968–2015) and seasonal source contributions to phosphorus (P) concentrations and cycling in the stratified Stockholm inner archipelago (IA), Baltic Sea. A drastic reduction of sewage P loads in the early 1970s reduced sewage from the major to a minor P source. Further P load reductions in the 1990s cut the direct contribution from the sewage point sources to the annual mean surface water P concentration from 10 μg l−1 (25%) to < 4 μg l−1 (12%). The largest contributions to the surface water P concentration are now (from 1996) inflowing seawater (37%), freshwater (25%), and P recycling from sediments below 20 m depth (26%). Variations in freshwater flushing give higher P concentrations in dry years, when dilution of P inputs from sediments and sewage is small, while in wet years, these inputs are greatly diluted. Source-partitioned phosphate uptake shows that the spring bloom is fueled mainly by P of seawater and freshwater origin, while the contribution from sewage point sources is minor. Since sediment P release is mostly recycled P from the settled spring bloom, the P inputs from seawater and freshwater are now the major drivers of the IA P cycle. Recycling of P from sediments boosts surface water P concentrations in autumn and winter, affecting management target concentrations.

scholarly journals Seasonal and Interannual Trends of Oceanographic Parameters over 40 Years in the Northern Adriatic Sea in Relation to Nutrient Loadings Using the EMODnet Chemistry Data Portal

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2280 ◽  
Author(s):  
Federica Grilli ◽  
Stefano Accoroni ◽  
Francesco Acri ◽  
Fabrizio Bernardi Aubry ◽  
Caterina Bergami ◽  
...  
Keyword(s):  
Climate Changes ◽  
Management Practices ◽  
Adriatic Sea ◽  
Nutrient Concentrations ◽  
Data Series ◽  
Mean Flow ◽  
Northern Adriatic Sea ◽  
Po River ◽  
Northern Adriatic

Long-term data series (1971–2015) of physical and biogeochemical parameters were analyzed in order to assess trends and variability of oceanographic conditions in the northern Adriatic Sea (NAS), a mid-latitude shallow continental shelf strongly impacted by river discharges, human activities and climate changes. Interpolation maps and statistical models were applied to investigate seasonal and spatial variability, as well as decadal trends of temperature, salinity, chlorophyll-a and nutrients. This analysis shows that sea surface temperature increased by +0.36% year−1 over four decades. Annual mean flow of the Po River markedly changed due to the occurrence of periods of persistent drought, whereas the frequency of flow rates higher than 3000 m3 s−1 decreased between 2006 and 2015. Moreover, we observed a long-term decrease in surface phosphate concentrations in Po River water (−1.34% year−1) and in seawater (in summer −2.56% year−1) coupled, however, to a significant increase in nitrate concentration in seawater (+3.80% year−1) in almost all seasons. These changes indicate that the nutrient concentrations in the NAS have been largely modulated, in the last forty years, by the evolution of environmental management practices and of the runoff. This implies that further alteration of the marine environment must be expected as a consequence of the climate changes.

Phytoplankton functional groups response to environmental parameters in Muling River basin of northeast China

2019 ◽  
Vol 55 ◽  
pp. 17
Author(s):  
Xu Sun ◽  
Patteson Chula Mwagona ◽  
Isaac Ekyamba Shabani ◽  
Wenjiu Hou ◽  
Xiaoyu Li ◽  
...  
Keyword(s):  
Functional Groups ◽  
River Basin ◽  
Light Availability ◽  
Seasonal Succession ◽  
Environmental Parameters ◽  
N:P Ratio ◽  
Ammonium Nitrogen ◽  
Nutrient Concentrations ◽  
Phytoplankton Functional Groups

The present study was carried out in the biggest tributary of Ussuri River of boundary between China and Russia. The Muling River basin has undergone a long-term dredging works, and waterbody became seriously turbid. The succession of phytoplankton functional groups succession and environmental factors in the river were sampled in 2015. We totally identified 83 species, belonging to 17 functional groups which 5 were predominant, including group F, M, MP, P and Y. The seasonal succession of phytoplankton functional groups was M/P-F/MP/P-MP/P. Results of Spearman correlation analysis and canonical correspondence analysis (CCA) revealed that phytoplankton functional groups were mainly influenced by nutrient concentrations and light availability including total nitrogen (TN), ammonium nitrogen (NH4+–N), nitrate nitrogen (NO3−–N), N:P ratio (N:P), water depth (D) and transparency (SD) in the basin.

scholarly journals Glaciochemistry of Cave Ice: Paradana and Snežna Caves, Slovenia

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 94
Author(s):  
Anne Carey ◽  
Matija Zorn ◽  
Jure Tičar ◽  
Matej Lipar ◽  
Blaž Komac ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Eastern Europe ◽  
Central And Eastern Europe ◽  
Nutrient Concentrations ◽  
Future Studies ◽  
Major Ion ◽  
Isotope Data ◽  
Lake Waters ◽  
Stable Isotope Data

Cave ice samples collected within karstic terrain have major ion and nutrient concentrations showing that the ice originates from local precipitation modified by the addition of Ca2+ and HCO3− from the dissolution of the local bedrock. Isotopic profiles of Paradana Cave ice are similar to those described in other ice caves in central and eastern Europe, where the profiles are developed through the freezing of cave pool or “lake” waters from the top downward during the onset of the cold portion of the year. Stable isotope data suggest future studies may yield a long-term paleo-environmental record for this location.

scholarly journals Short- and Long-Term Effects of Lime and Gypsum Applications on Acid Soils in a Water-Limited Environment: 1. Grain Yield Response and Nutrient Concentration

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1213 ◽  
Author(s):  
Geoffrey C. Anderson ◽  
Shahab Pathan ◽  
James Easton ◽  
David J. M. Hall ◽  
Rajesh Sharma
Keyword(s):  
Grain Yield ◽  
Soil Layer ◽  
Acid Soils ◽  
Triticum Aestivum L ◽  
Nutrient Concentrations ◽  
Yield Response ◽  
Long Term Effects ◽  
Grain Yields ◽  
Growing Seasons

Surface (0–10 cm) and subsoil (soil layers below 10 cm) acidity and resulting aluminum (Al) toxicity reduce crop grain yields. In South Western Australia (SWA), these constraints affect 14.2 million hectares or 53% of the agricultural area. Both lime (L, CaCO3) and gypsum (G, CaSO4) application can decrease the toxic effect of Al, leading to an increase in crop grain yields. Within the region, it is unclear if G alone or the combined use of L and G has a role in alleviating soil acidity in SWA, due to low sulfate S (SO4–S) sorption properties of the soil. We present results from three experiments located in the eastern wheatbelt of SWA, which examined the short-term (ST, 2 growing seasons), medium-term (MT, 3 growing seasons), and long-term (LT, 7 growing seasons over 10 years) effects of L and G on grain yield and plant nutrient concentrations. Despite the rapid leaching of SO4–S and no self-liming impact, it was profitable to apply G, due to the significant ST grain yield responses. The grain yield response to G developed even following relatively dry years, but declined over time due to SO4–S leaching. At the LT experimental site had received no previous L application, whereas, at the ST and MT sites, L had been applied by the grower over the previous 5–10 years. For the LT site, the most profitable treatment for wheat (Triticum aestivum L.) grain yield, was the combined application of 4 t L ha−1 with 2 t G ha−1. At this site, the 0–10 cm soil pHCaCl2 was 4.6, and AlCaCl2 was greater than 2.5 mg kg−1 in the 10–30 cm soil layer. In contrast, at the ST and MT sites, the pHCaCl2 of 0–10 cm soil layer was ≥5.5; it was only profitable to apply G to the MT site where the soil compaction constraint had been removed by deep ripping. The use of L increases soil pHCaCl2, resulting in the improved availability of anions, phosphorus (P) in the LT and molybdenum (Mo) at all sampling times, but reduced availability of cations zinc (Zn) in the LT and manganese (Mn) at all sampling. The application of G reduced Mo concentrations, due to the high SO4–S content of the soil.

scholarly journals Enhancement of Long-Term External–Internal Correlation by Phase-Shift Detection and Correction Based on Concurrent External Bellows and Internal Navigator Signals

2019 ◽  
Vol 4 (2) ◽  
pp. 377-389 ◽  
Author(s):  
Andrew R. Milewski ◽  
Devin Olek ◽  
Joseph O. Deasy ◽  
Andreas Rimner ◽  
Guang Li
Keyword(s):  
Phase Shift ◽  
Shift Detection
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