Uptake of arsenic by Aster tripolium in relation to rhizosphere oxidation

1991 ◽  
Vol 69 (12) ◽  
pp. 2670-2677 ◽  
Author(s):  
M. L. Otte ◽  
I. M. J. Dekkers ◽  
J. Rozema ◽  
R. A. Broekman
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Bulk Soil ◽  
Marsh Soil ◽  
Salt Marsh Plants ◽  
Aster Tripolium ◽  
Detoxification Mechanism ◽  
Key Factor ◽  
Salt Marsh Soil ◽  
Reduced State

Arsenic present in salt marsh soil is taken up by plants and subsequently transferred to other parts of the ecosystem. The reduced state of the bulk soil of salt marshes favours the mobility of arsenic. In the rhizosphere of plants however, arsenic may be immobilized owing to oxidation of arsenic (III) to less mobile arsenic (V) and adsorption to iron (hydr-)oxides. In a field survey iron concentrations in the vicinity of roots of Aster tripolium were higher than in the bulk soil. In a greenhouse experiment accumulation of arsenic and iron in the rhizosphere occurred, which could be due to the oxidizing activity of plant roots and (or) microorganisms. This process stimulates uptake of arsenic by salt marsh plants. The formation of an iron plaque seems to play an important role in the uptake of arsenic by salt marsh plants, as was indicated by an incubation experiment with root parts of A. tripolium. The results of the experiments indicate that iron plays a key factor in determining the mobility of arsenic in salt marsh soils and in the uptake and translocation processes in the plants. Although oxidation processes in the rhizosphere enhance uptake of arsenic, it may be an important detoxification mechanism for the plants. Key words: arsenic, Aster tripolium, iron, rhizosphere, salt marsh.

scholarly journals Machine-Learning Classification of Soil Bulk Density in Salt Marsh Environments

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4408
Author(s):  
Iman Salehi Hikouei ◽  
S. Sonny Kim ◽  
Deepak R. Mishra
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
Salt Marsh ◽  
Bulk Density ◽  
Remote Sensing Data ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Marsh Soil ◽  
Landsat 7 ◽  
Salt Marsh Soil

Remotely sensed data from both in situ and satellite platforms in visible, near-infrared, and shortwave infrared (VNIR–SWIR, 400–2500 nm) regions have been widely used to characterize and model soil properties in a direct, cost-effective, and rapid manner at different scales. In this study, we assess the performance of machine-learning algorithms including random forest (RF), extreme gradient boosting machines (XGBoost), and support vector machines (SVM) to model salt marsh soil bulk density using multispectral remote-sensing data from the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) platform. To our knowledge, use of remote-sensing data for estimating salt marsh soil bulk density at the vegetation rooting zone has not been investigated before. Our study reveals that blue (band 1; 450–520 nm) and NIR (band 4; 770–900 nm) bands of Landsat-7 ETM+ ranked as the most important spectral features for bulk density prediction by XGBoost and RF, respectively. According to XGBoost, band 1 and band 4 had relative importance of around 41% and 39%, respectively. We tested two soil bulk density classes in order to differentiate salt marshes in terms of their capability to support vegetation that grows in either low (0.032 to 0.752 g/cm3) or high (0.752 g/cm3 to 1.893 g/cm3) bulk density areas. XGBoost produced a higher classification accuracy (88%) compared to RF (87%) and SVM (86%), although discrepancies in accuracy between these models were small (<2%). XGBoost correctly classified 178 out of 186 soil samples labeled as low bulk density and 37 out of 62 soil samples labeled as high bulk density. We conclude that remote-sensing-based machine-learning models can be a valuable tool for ecologists and engineers to map the soil bulk density in wetlands to select suitable sites for effective restoration and successful re-establishment practices.

scholarly journals Nocardiopsis halotolerans sp. nov., isolated from salt marsh soil in Kuwait.

2002 ◽  
Vol 52 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Sheikha S Al-Zarban ◽  
Ibrahim Abbas ◽  
Azza A Al-Musallam ◽  
Ulrike Steiner ◽  
Erko Stackebrandt ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Marsh Soil ◽  
Salt Marsh Soil

No Evidence for Long-term Impacts of Oil Spill Contamination on Salt Marsh Soil Nitrogen Cycling Processes

2020 ◽  
Vol 43 (4) ◽  
pp. 865-879
Author(s):  
Charles A. Schutte ◽  
John M. Marton ◽  
Anne E. Bernhard ◽  
Anne E. Giblin ◽  
Brian J. Roberts
Keyword(s):  
Salt Marsh ◽  
Nitrogen Cycling ◽  
Oil Spill ◽  
Soil Nitrogen ◽  
Marsh Soil ◽  
Salt Marsh Soil ◽  
Soil Nitrogen Cycling

Crude Oil Effects on Redox Status of Salt Marsh Soil in Louisiana

2017 ◽  
Vol 81 (3) ◽  
pp. 647-653 ◽  
Author(s):  
B.M. Levine ◽  
J.R. White ◽  
R.D. DeLaune ◽  
K. Maiti
Keyword(s):  
Salt Marsh ◽  
Crude Oil ◽  
Redox Status ◽  
Marsh Soil ◽  
Salt Marsh Soil

Oxygen dynamics in a salt-marsh soil and in Suaeda maritima during tidal submergence

2013 ◽  
Vol 92 ◽  
pp. 73-82 ◽  
Author(s):  
Timothy D. Colmer ◽  
Ole Pedersen ◽  
Anne M. Wetson ◽  
Timothy J. Flowers
Keyword(s):  
Salt Marsh ◽  
Marsh Soil ◽  
Suaeda Maritima ◽  
Salt Marsh Soil ◽  
Oxygen Dynamics

scholarly journals Phenanthrene contamination and ploidy level influence the rhizosphere microbiome of Spartina

2019 ◽  
Author(s):  
Armand Cavé-Radet ◽  
Cécile Monard ◽  
Abdelhak El-Amrani ◽  
Armel Salmon ◽  
Malika Ainouche ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Rhizosphere Soil ◽  
Oil Spills ◽  
Its Region ◽  
Hydrocarbon Contamination ◽  
Rrna Gene ◽  
Salt Marsh Plants ◽  
Rhizosphere Microbiome ◽  
Contamination Events

AbstractSpartina spp. are widely distributed salt marsh plants that have a recent history of hybridization and polyploidization. These evolutionary events have resulted in species with a heightened resilience to hydrocarbon contamination, which could make them an ideal model plant for the phytoremediation/reclamation of contaminated coastal ecosystems. However, it is still unknown if allopolyploidization events also resulted in differences in the plant rhizosphere-associated microbial communities, and if this could improve the plant phytoremediation potential. Here, we grew two parental Spartina species, their hybrid and the resulting allopolyploid in salt marsh sediments that were contaminated or not with phenanthrene, a model tricyclic PAH. The DNA from the rhizosphere soil was extracted and the bacterial 16S rRNA gene and ITS region were amplified and sequenced. Generally, both the presence of phenanthrene and the identity of the plant species had significant influences on the bacterial and fungal community structure, composition and diversity. In particular, the allopolyploid S. anglica, harbored a more diverse bacterial community in its rhizosphere, and relatively higher abundance of various bacterial and fungal taxa. Putative hydrocarbon degraders were significantly more abundant in the rhizosphere soil contaminated with phenanthrene, with the Nocardia genus being significantly more abundant in the rhizosphere of S. anglica. Overall our results are showing that the recent polyploidization events in the Spartina did influence the rhizosphere microbiome, both under normal and contaminated conditions, but more work will be necessary to confirm if these differences result in a higher phytoremediation potential.ImportanceSalt marshes are at the forefront of coastal contamination events caused by marine oil spills. Microbes in these environments play a key role in the natural attenuation of these contamination events, often in association with plant roots. One such plant is the Spartina, which are widely distributed salt marsh plants. Intriguingly, some species of the Spartina show heightened resistance to contamination, which we hypothesized to be due to differences in their microbiota. This was indeed the case, with the most resistant Spartina also showing the most different microbiota. A better understanding of the relationships between the Spartina and their microbiota could improve the coastal oil spill clean-up strategies and provide green alternatives to more traditional physico-chemical approaches.

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