scholarly journals Sedimentary Organic Matter Load Influences the Ecological Effects and Potential Risks of Submerged Macrophyte Restoration Through Rhizosphere Metabolites

2021 ◽  
Author(s):  
Chuan Wang ◽  
Huihui Wang ◽  
Liping Zhang ◽  
Yahua Li ◽  
Wenhao Yan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Lake Management ◽  
Decanoic Acid ◽  
N Accumulation ◽  
Rehabilitation Technology ◽  
Potential Risks ◽  
Release Potential ◽  
Labile N ◽  
In Situ Collection

Abstract Aims Rehabilitation of submerged vegetation is one of the commonly used techniques for the ecological restoration of shallow lakes. The changes of pollution structure in sediments caused by plant recovery and the rhizosphere chemical process under different sediment organic matter (SOM) levels are theoretical basis for the rational application of plant rehabilitation technology in lake management.Methods A circulating extraction system was designed for in situ collection of rhizospheric metabolites especially for the submerged plants. We explored how Vallisneria natans (V. natans) mediate the changes in sediment N and P through rhizospheric metabolites under low (4.94%) and high (17.35%) SOM levels. Results By analysing 63 rhizospheric metabolites from V. natans, glucitol was found to be 146.82% lower in the low SOM than in the high SOM treatment. NH4-N and NO2-N increased by 57% and 68.39%, respectively, in the high SOM treatment, while approximately one-seventh Inorg-P was transferred from Fe/Al-P to Ca-P in the low SOM treatment. The metabolites lactic acid, 3-hydroxybutyric acid, and phosphoric acid mediated NH4-N accumulation. Additionally, 3-hydroxy-decanoic acid and adipic acid mediated the transformation of Fe/Al-P to Ca-P.Conclusions The growth of V. natans significantly changed Inorg-N or Inorg-P fractions. The changes were SOM level-dependent and rhizosphere metabolites related. This study emphasised the benefit of V. natans rehabilitation at low SOM level. When restoring submerged macrophytes from high SOM sediment, care should be taken due to the release potential of labile N and P forms.

scholarly journals Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

2010 ◽  
Vol 7 (11) ◽  
pp. 3473-3489 ◽  
Author(s):  
J. Holtvoeth ◽  
H. Vogel ◽  
B. Wagner ◽  
G. A. Wolff
Keyword(s):  
Organic Matter ◽  
Lipid Biomarkers ◽  
Lake Ohrid ◽  
Labile Organic Matter ◽  
Glacial Sediments ◽  
Plant Matter ◽  
Lipid Biomarker ◽  
First Results ◽  
Near Shore

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

scholarly journals Sediment community responses to marine vs. terrigenous organic matter in a submarine canyon

2013 ◽  
Vol 10 (1) ◽  
pp. 67-80 ◽  
Author(s):  
W. R. Hunter ◽  
A. Jamieson ◽  
V. A. I. Huvenne ◽  
U. Witte
Keyword(s):  
Organic Matter ◽  
Feeding Activity ◽  
N Uptake ◽  
Bacterial Biomass ◽  
Submarine Canyon ◽  
Stable Isotope Labelling ◽  
C And N ◽  
13C Label ◽  
Experimental Treatments

Abstract. The Whittard Canyon is a branching submarine canyon on the Celtic continental margin, which may act as a conduit for sediment and organic matter (OM) transport from the European continental slope to the abyssal sea floor. In situ stable-isotope labelling experiments were conducted in the eastern and western branches of the Whittard Canyon, testing short-term (3–7 days) responses of sediment communities to deposition of nitrogen-rich marine (Thalassiosira weissflogii) and nitrogen-poor terrigenous (Triticum aestivum) phytodetritus. 13C and 15N labels were traced into faunal biomass and bulk sediments, and the 13C label traced into bacterial polar lipid fatty acids (PLFAs). Isotopic labels penetrated to 5 cm sediment depth, with no differences between stations or experimental treatments (substrate or time). Macrofaunal assemblage structure differed between the eastern and western canyon branches. Following deposition of marine phytodetritus, no changes in macrofaunal feeding activity were observed between the eastern and western branches, with little change between 3 and 7 days. Macrofaunal C and N uptake was substantially lower following deposition of terrigenous phytodetritus with feeding activity governed by a strong N demand. Bacterial C uptake was greatest in the western branch of the Whittard Canyon, but feeding activity decreased between 3 and 7 days. Bacterial processing of marine and terrigenous OM were similar to the macrofauna in surficial (0–1 cm) sediments. However, in deeper sediments bacteria utilised greater proportions of terrigenous OM. Bacterial biomass decreased following phytodetritus deposition and was negatively correlated to macrofaunal feeding activity. Consequently, this study suggests that macrofaunal–bacterial interactions influence benthic C cycling in the Whittard Canyon, resulting in differential fates for marine and terrigenous OM.

Microbial-accessibility-dependent electron shuttling of in situ solid-phase organic matter in soils

Geoderma ◽  
2019 ◽  
Vol 338 ◽  
pp. 1-4 ◽  
Author(s):  
Wenbing Tan ◽  
Beidou Xi ◽  
Guoan Wang ◽  
Xiaosong He ◽  
Rutai Gao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solid Phase ◽  
Electron Shuttling

scholarly journals The in situ bacterial production of fluorescent organic matter; an investigation at a species level

2017 ◽  
Vol 125 ◽  
pp. 350-359 ◽  
Author(s):  
B.G. Fox ◽  
R.M.S. Thorn ◽  
A.M. Anesio ◽  
D.M. Reynolds
Keyword(s):  
Organic Matter ◽  
Bacterial Production ◽  
Species Level

scholarly journals Effect of soil interacting herbicides on soybean nodulation in Balcarce, Argentina

1999 ◽  
Vol 34 (7) ◽  
pp. 1167-1173 ◽  
Author(s):  
Norma Gonzalez ◽  
Juan Jose Eyherabide ◽  
Maria Ignacia Barcelonna ◽  
Alfredo Gaspari ◽  
Silvina Sanmartino
Keyword(s):  
Organic Matter ◽  
Dry Weight ◽  
Control Treatment ◽  
Growth Stages ◽  
N Fixation ◽  
Buenos Aires Province ◽  
N Accumulation ◽  
Nodule Number ◽  
Seed Growth ◽  
Chlorimuron Ethyl

Two trials were performed in Balcarce, Argentina (37° 45' LS; 58° 18' LW) during 1993-94, to assess the effect of eight herbicides applied individually or in tank mixtures, on nodule number, nodule dry weight, seed yield and N percent in seed in soybean Asgrow 3205, inoculated with Bradyrhizobium japonicum CB 1809. Individual herbicides and doses in kg ha-1 of a.i. were metribuzin (0.48), acetochlor (0.90), metolachlor (1), flumioxazin (0.075), trifluralin (0.96), imazaquin (0.20), imazethapyr (0.10) and chlorimuron ethyl (0.0125). The mixtures were metribuzin+acetochlor (0.48+0.9), flumioxazin+acetochlor (0.075+0.9), imazaquin+acetochlor (0.2+0.9), metribuzin+metolachlor (0.48+1.92), and flumioxazin+ metolachlor (0.075+1.92). A control treatment without herbicides was included. Both trials were laid out as randomized complete blocks with four replicates, on a loam illitic thermic petrocalcic Paleudoll, 5.7% organic matter (OM), 25% clay, 30.4 cmol kg-1 CEC. Nodules were sampled at V2 (second node), V6 (sixth node) and R5 (beginning seed) growth stages. Herbicides did not significantly affect the beginning of nodulation or nodule number and mass at R5, not either grain yield or N accumulation. This indicates lack of interference between soil interacting herbicides and N fixation in the high organic matter, loam soils of SE Buenos Aires province, even though a tendency in less number and dry weight of nodules was evident at the two latter growth stages.

scholarly journals Agro morphological characterization of cashew trees (Anacardium occidental L.), in improvement for the high yield and high quality of raw nuts in Burkina Faso

2021 ◽  
Vol 14 (9) ◽  
pp. 3188-3199
Author(s):  
Windpouiré Vianney Tarpaga ◽  
Larbouga Bourgou ◽  
Moussa Guira ◽  
Albert Rouamba
Keyword(s):  
Burkina Faso ◽  
Core Collection ◽  
Morphological Diversity ◽  
Morphological Characterization ◽  
High Yield ◽  
Morphological Description ◽  
Average Weight ◽  
In Situ Collection

The cashew sector has taken a great economic interest, due to the strong global demand for raw nuts. However, in Burkina Faso, the productivity of orchards still remains low, a consequence of a lack of breeding program on the species. In order to increase yields and improve the quality of the raw nut, efficient clones must be developed. Surveys were carried out and a primary in situ collection was made from which a core collection of 15 trees was extracted. An agro-morphological description of the selected trees and an analysis of the structuration of the variability within them were carried out. The study revealed appreciable agro-morphological diversity through shape, size and color of apple, type of inflorescence, fruiting period and the health of trees. A structure of diversity based on agronomic criteria led to identify 5 groups of trees, characterized by an average weight of the nut between 6.64 and 8.32 g, a kernel rate between 28.10 and 31.26% and a yield per tree between 34.27 and 104.42 kg. Performing trees will be erected as heads of clones for the production of grafted plants. La filière anacarde a pris un grand intérêt économique, suite à la forte demande mondiale en noix brutes. Cependant, au Burkina Faso, la productivité des vergers demeure encore faible, conséquence d’une absence de sélection variétale du matériel végétal. En vue d’accroître les rendements et d’améliorer la qualité de la noix brute, une recherche de clones performants était indispensable. Des prospections ont été conduites et une collection primaire in situ a été constituée dont une core collection de 15 arbres a été extraite. Une description agro-morphologique des arbres sélectionnés et une analyse de la structuration de la variabilité en son sein ont été conduites. L’étude a révélé une diversité agro morphologique appréciable à travers la forme, le calibre et la couleur de la pomme, le type d’inflorescence, la période de fructification et l’état sanitaire des arbres. Une structuration de la diversité basée sur les critères agronomiques a permis d’identifier 5 groupes d’arbres, caractérisés par un poids moyen de la noix compris entre 6,64 et 8,32 g, un taux d’amande compris entre 28,10 et 31,26% et un rendement par arbre compris entre 34,27 et 104,42 kg. Les arbres les plus performants constitueront des têtes de clones pour la production de plants par greffage.

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