Selenium Speciation of Surface Sediments from Saline Lakes of the Soan-Sakesar Valley Salt-Range, Pakistan

1999 ◽  
Vol 34 (4) ◽  
pp. 575-588 ◽  
Author(s):  
Shahzad Afzal ◽  
Mohammad Younas ◽  
Khadim Hussain
Keyword(s):  
Lake Sediments ◽  
Surface Sediments ◽  
Chemical Species ◽  
Dry Weight ◽  
Drainage Water ◽  
Nutrient Loads ◽  
Organic C ◽  
Linear Relationships ◽  
Salt Range ◽  
Total Selenium

Abstract The chemical species of selenium from the surface sediments from three eutroph-ic lakes of the Soan-Sakesar Valley were examined. The major objectives of the study were to examine the oxidation states of selenium in the lake sediments. The following selenium concentrations were observed from lakes Uchhali, Khabbaki and Jahlar, respectively: total selenium: 4.03, 1.55 and 1.4 mg/kg; Se+VI: 0.86, 0.39 and 0.31 mg/kg; Se+IV: 0.95, 0.27 and 0.25 mg/kg; Se-II:1.15, 0.45 and 0.33; and Se0: 1.17, 0.48 and 0.53 mg/kg. Lake sediments have higher nitrogen (0.04—0.35% of dry weight) and phosphorus (0.04—0.29% of dry weight) levels due to agriculture drainage water and sewage waste from small villages. X-ray diffraction analysis has shown that albite, calcite, chlorite, illite and quartz minerals were present in the sediments of lakes Uchhali, Khabbaki and Jahlar. Kaolinite was present only in lakes Uchhali and Khabbaki and goethite only in Lake Uchhali. Linear relationships were observed between selenium fractions, and minerals present in these lakes point out the phenomena of adsorption on the surface of these minerals. The organic C contents of 2.2, 2.8 and 3.1% dry weight in lakes Uchhali, Khabbaki and Jahlar, respectively, show linear relationships with Se-II, Se0 and total selenium. It suggests that Se in the sediments is highly associated with the sediment organic fraction. The results indicate that nutrient loads and organic C are responsible for the high microbial activity, which reduces sele-nates to more insoluble Se species in the lake sediments.

scholarly journals Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

2010 ◽  
Vol 7 (1) ◽  
pp. 1131-1165 ◽  
Author(s):  
J. Möbius ◽  
N. Lahajnar ◽  
K.-C. Emeis
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Surface Sediments ◽  
Eastern Mediterranean ◽  
Nitrogen Isotope ◽  
Organic C ◽  
Deep Waters ◽  
Spatially Distributed ◽  
Temporal And Spatial ◽  
Recent Sediments

Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually depleted δ15N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ15N on sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ15N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) that present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and δ15N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt the need of enhanced primary production for sapropel formation.

scholarly journals Seasonal Partitioning of Leaf and Fruit Potassium and Fruit Dry Matter in French Prune Trees at Various Potassium Levels

1991 ◽  
Vol 116 (6) ◽  
pp. 981-986 ◽  
Author(s):  
F.J.A. Niederholzer ◽  
R.M. Carlson ◽  
K. Uriu ◽  
N.H. Willits ◽  
J.P. Pearson
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Fruit Growth ◽  
Growth Stages ◽  
Dry Matter Accumulation ◽  
Accumulation Rates ◽  
Mature Trees ◽  
Linear Relationships ◽  
Weight Yield ◽  
High K

A study was undertaken to determine the seasonal dynamics of leaf and fruit K content and the influence of tree K status and fruit growth on leaf and fruit K accumulation rates in French prune (Prunus domestics L. cv. d'Agen). Mature trees in a commercial orchard were treated with various rates of K2 SO4. (O to ≈20 kg/tree) in the fall. Fruit dry weight yield per tree at harvest and fruit K content were higher for high-K trees, but fruit percent K (by dry weight) was ≈1.0% for all trees. Leaf scorch and subsequent abscission severely reduced the canopy of K-deficient trees. Significant positive linear relationships between leaf and fruit K accumulation rates existed for the periods of 28 Apr.-28 May (May) and 28 May-7 July (June). A significant negative linear relationship existed between these two criteria from 7 July-3 Aug. (July). May (0.237 mg K per fruit-day) and July (0.267 mg K per fruit-day) mean fruit K accumulation rates were similar, but both were significantly higher (P = 0.001) than those for June (0.140 mg K per fruit-day). Mean leaf K accumulation rates for May (- 0.007 mg K per leaf-day) and July (-0.010 mg K per leaf-day) were similar, but both were significantly (P = 0.001) less than for June (0.005 mg K per leaf-day). Potassium per fruit accumulation was highest in trees with highest K status. Periods of net leaf K efflux and influx did not precisely correlate with fruit growth stages measured by fruit dry weight. The period of lowest fruit K accumulation (28 May-7 July) coincided with the period of maximum dry matter accumulation by the kernel. After 7 July, all increases in fruit dry weight and K content were due to mesocarp growth.

Nutrient Content of the Aboveground Tissue of 12-week-old Loblolly Pine Intraprovenance and Interprovenance Crosses

1975 ◽  
Vol 5 (4) ◽  
pp. 592-598 ◽  
Author(s):  
R. A. Woessner ◽  
C. B. Davey ◽  
B. E. Crabtree ◽  
J. D. Gregory
Keyword(s):  
Loblolly Pine ◽  
Dry Matter ◽  
Dry Weight ◽  
Nutrient Content ◽  
Seed Source ◽  
Good Linear ◽  
Available Nutrients ◽  
Seed Sources ◽  
Linear Relationships ◽  
Aboveground Tissue

Nutrient content (P, K, Ca, Mg) of the aboveground tissue of a series of full-sib loblolly crosses was found to vary by genotype. Variability among and within seed sources is indicated for the ability to absorb Ca and Mg. Absorption of P and K was not found to be dependent on seed source, but the full-sib crosses differ. Good linear relationships were found between plant dry weight and weight of element but not between plant dry weight and percentage of element. Certain highly efficient crosses can be expected to be good producers of dry matter on sites low in available nutrients.

Staurosirella andino-patagonica sp. nov. (Bacillariophyta) from lake sediments in Patagonia, Argentina

Phytotaxa ◽  
2019 ◽  
Vol 402 (3) ◽  
pp. 131 ◽  
Author(s):  
JOSÉ MARÍA GUERRERO ◽  
MARÍA LUJÁN GARCÍA ◽  
EDUARDO A. MORALES
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lake Sediments ◽  
Surface Sediments ◽  
Geographic Area ◽  
New Taxon ◽  
Diatom Flora ◽  
The Andes ◽  
Distinct Morphology ◽  
Scanning Electron

Staurosirella andino-patagonica, a new araphid diatom found in Holocene and recent surface sediments from lakes located in the Andes and adjacent steppe of Patagonia (Argentina), is described on the basis of light and scanning electron microscopy observations and comparison with related taxa. Although the elliptic valve outline of the new taxon resembles the smaller specimens of several Staurosirella species, ultrastructural features such as the presence of two spines on each virga and their distinct morphology -serrated with thickenings at the base- make Staurosirella andino-patagonica unique within the genus. Our study contributes to the knowledge of the Patagonian araphid diatom flora, a rather unexplored geographic area, and so we assume that, as additional areas are studied in detail, they will likely continue to yield new taxa.

scholarly journals Total phosphorus and organic matter content in bottom sediments of lake under restoration measures with iron treatment

2010 ◽  
Vol 10 (3-4) ◽  
pp. 139-145 ◽  
Author(s):  
Katarzyna Kowalczewska-Madura ◽  
Renata Dondajewska ◽  
Ryszard Gołdyn
Keyword(s):  
Organic Matter ◽  
Lake Sediments ◽  
Total Phosphorus ◽  
Bottom Sediments ◽  
Organic Matter Content ◽  
Dry Weight ◽  
Matter Content ◽  
Iron Treatment ◽  
Iron Sulphate ◽  
Restoration Measures

Total phosphorus and organic matter content in bottom sediments of lake under restoration measures with iron treatmentRusałka Lake is a shallow, man-made, strongly eutrophicated reservoir, being a place of recreational activities for Poznan citizens. Restoration measures with the use of iron sulphate were conducted in years 2006-2007. Phosphorus and organic matter concentrations in lake sediments were analyzed in years 2005-2007 at two research stations (profundal and littoral) to determine its changes under the influence of restoration. Greater phosphorus concentrations were noted in profundal (max 1.55 mg P g-1dry weight (DW)) than in littoral (max 0.98 mg P g-1DW). An increase of P amount in sediment was observed after iron treatment. Among phosphorus fractions Res-P dominated, i.e. phosphorus biologically unavailable for organisms. Organic matter content reached 23.1% in profundal, while 14.8% in littoral. Its amount decreased in following years.

scholarly journals Distribution and sources of n-alkanes in surface sediments of Taihu Lake, China

2016 ◽  
Vol 42 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Yunlong Yu ◽  
Yuanyuan Li ◽  
Zhigang Guo ◽  
Hua Zou
Keyword(s):  
Surface Sediment ◽  
Surface Sediments ◽  
Taihu Lake ◽  
Higher Plants ◽  
Complex Mixture ◽  
Dry Weight ◽  
Short Chain ◽  
Sediment Samples ◽  
Total Concentrations ◽  
Long Chain

Abstract The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng g−1 (dry weight). There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn), carbon preference index (CPI), unresolved complex mixture (UCM), hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR) and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.

Biometrics, Carbon and Nitrogen Content in Two Cnidarians: Urticina Felina and Alcyonium Digitatum

1996 ◽  
Vol 76 (3) ◽  
pp. 595-602 ◽  
Author(s):  
A. Migné ◽  
D. Davoult ◽  
M.A. Janquin ◽  
A. Kupka
Keyword(s):  
Organic Carbon ◽  
Nitrogen Content ◽  
Dry Weight ◽  
Sea Anemones ◽  
Carbon And Nitrogen ◽  
Rapid Measurement ◽  
Constant Size ◽  
Linear Relationships ◽  
Carbon And Nitrogen Content ◽  
Biometrical Study

A biometrical study was conducted on two common cnidarians: Alcyonium digitatum (Octocorallia) and Urticina felina (Hexacorallia). The aim was to relate both the carbon and the nitrogen content of these species to a simple and rapid measurement. As the simplest measurement that can be done on A. digitatum is a measurement of size, relationships were determined between the height of a colony and its organic carbon (OC=0.0002 H2.0254, n=104, γ2=0·923) and nitrogen (N=0.00004 H2.0283, n=104, γ2=0.928) content. As no constant size could be determined on sea anemones, linear relationships were established between dry weight (DW) and organic carbon (OC=0.419 DW, n=65, r=0.995) and nitrogen (N=0.095 DW, n=65, r=0.997) content in U. felina. All these relationships were highly significant (P<0.1%) and appeared useful to express biomass of the two species in terms of carbon or nitrogen and then to consider dynamic processes such as respiration or excretion as fluxes of carbon and nitrogen.

Higher seasonal variation of actinobacterial communities than spatial heterogeneity in the surface sediments of Taihu Lake, China

2013 ◽  
Vol 59 (5) ◽  
pp. 353-358 ◽  
Author(s):  
Jianjun Wang ◽  
Yong Zhang ◽  
Zhengkui Li ◽  
Ji Shen
Keyword(s):  
Seasonal Variation ◽  
Spatial Heterogeneity ◽  
Lake Sediments ◽  
Surface Sediments ◽  
Taihu Lake ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Detrended Correspondence Analysis ◽  
Rrna Gene ◽  
Clone Libraries ◽  
Principal Coordinates

Much more attention has been paid to the actinobacterial community in soils or water columns of aquatic habitats. However, there are few studies on their composition and diversity in lake sediments. Here, we used denaturing gradient gel electrophoresis and clone libraries of partial 16S rRNA gene to study the spatial variations of actinobacterial communities across 4 seasons in the surface sediments of the shallow, subtropical Taihu Lake. Cluster analysis based on fingerprints showed clear spatiotemporal variations of actinobacterial communities and higher seasonal variation than spatial heterogeneity. Based on clone libraries, this pattern was supported by the principal coordinates analysis in the phylogenetic context and by detrended correspondence analysis on the operational taxonomic unit table. Additionally, phylogenetic analysis showed that the putative freshwater-specific actinobacterial lineages (e.g., acI) were also detected in the lake sediments, which suggests that these subclusters may also adapt to the sediment environments. Summarily, our results suggested that actinobacterial communities of the surface sediments were more affected by seasonal variation than spatial heterogeneity in the intrahabitat of Taihu Lake.

scholarly journals In vitro Sugar and Water Use in Diploid and Tetraploid Genotypes of Daylily (Hemerocallis spp.) in Liquid Medium as Affected by Density and Plant Growth Regulators

HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 325-328 ◽  
Author(s):  
Jeffrey Adelberg ◽  
Maria Delgado ◽  
Jeffrey Tomkins
Keyword(s):  
Liquid Medium ◽  
Water Use ◽  
Biomass Yield ◽  
Dry Weight ◽  
Fresh Weight ◽  
Water Requirements ◽  
Linear Relationships ◽  
Mass Volume ◽  
Orbital Shaker

Two tetraploid and two diploid genotypes of Hemerocallis spp. were micropropagated on an orbital shaker in Murashige and Skoog liquid medium in a factorial combination of two sucrose concentrations (90 mm and 180 mm), two 6-benzylaminopurine (benzyladenine) concentrations (0.32 μm and 3.2 μm), at two densities (57 explants/L and 171 explants/L), in the presence (0.32 μm) and absence of α-cyclopyl-α-[4-mehtoxyphenyl]-5-pyrimididinmethanol (ancymidol). There were linear relationships between fresh weight and water use (R 2 = 0.800, P < 0.0001), dry weight and sucrose use (R 2 = 0.636, P < 0.0001), and relative dry weight (dry weight/fresh weight = relative dry weight) to concentration of sucrose residual in medium after culture (R 2 = 0.553, P < 0.0001). Eighty-five percent of the water used and 74% of the sucrose used were incorporated as plant fresh weight and dry weight, respectively. A 1% increase in percent sucrose residual (mass/volume in spent medium) was correlated to an increase of 1.8% relative dry weight over the range 7% to 22% relative dry weight. In vessels with 90 mm initial sucrose, where the most growth had occurred (>15 g fresh weight), sucrose was depleted (<0.2% sucrose) and plantlets had the lowest relative dry weight (≈6.9%). In vessels from 180 mm initial sucrose, with similarly high fresh weight, plantlets had 12.0% relative dry weight with 2.1% sucrose residual in medium. Fresh weight, dry weight, or relative dry weight of plantlets in the laboratory did not correlate with subsequent survival or growth in the greenhouse. Plantlets grown without ancymidol at the lower benzyladenine concentration acclimatized to the greenhouse with 93% survival. However, greenhouse survival of plants grown with ancymidol and a higher level of benzyladenine was only 4%. ‘Barbara Mitchell’ was the largest plant in the laboratory, but often had poorest growth in the greenhouse. When optimizing a liquid micropropagation protocol for larger vessels, sucrose and water requirements may be directly related to targeted biomass yield, but each genotype needs to be handled independently with ex vitro validation of plant vigor.

scholarly journals Upland Rice Growth after Low-Input Amendments on Upland Soil in West Kalimantan, Indonesia

2019 ◽  
Vol 24 (3) ◽  
pp. 119
Author(s):  
Sutarman Gafur ◽  
Ismahan Umran
Keyword(s):  
Upland Rice ◽  
Dry Weight ◽  
Cow Manure ◽  
Upland Soil ◽  
Organic C ◽  
West Kalimantan ◽  
Low Input ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Poor Soil

Upland soils in West Kalimantan used for agricultural activities reach about 483,077 hectares. However, this land potential is not yet optimally exploited due to poor soil fertility. To increase its productivity, there is a need to invent technology packages that are not only effective but also efficient. This research is designed to study the growth of upland rice and the changes in certain soil properties after low-input treatment applications. This research used a Completely Randomized Design. There were 6 treatments and 4 replications. The treatment levels were P0 (no treatment), P1 (7tons of cow manure/ha + 300 kg NPK compound), P2 (15tons of cow manure/ha + 300 kg NPK compound), P3 (7tons of compost/ha + 300 kg NPK compound), P4 (15tons of compost/ha + 300 kg NPK compound), and P5 (600 kg/ha NPK compound). Parameters included plant height and dry weight, NPK absorptions, soil pH, organic C content, and NPK contents after soil treatment. The results showed that upland rice responded well to low-input amendment treatments compared to that of grow-in soil with no input treatments. Both the treatments using 15 tons of cow manure and 15 tons of rice straw compost per hectare, each plus 300 kg of NPK, were suggested to be further research topics for treatments in upland soil of West Kalimantan.

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