scholarly journals Effects of Carbon Addition on Dissimilatory Fe(III) Reduction in Freshwater Marsh and Meadow Wetlands

2018 ◽  
Vol 10 (11) ◽  
pp. 4309 ◽  
Author(s):  
Xiaoyan Zhu ◽  
Yuxiang Yuan ◽  
Ming Jiang
Keyword(s):  
Iron Reduction ◽  
Reduction Rate ◽  
Negative Relationship ◽  
Sanjiang Plain ◽  
Freshwater Marsh ◽  
Freshwater Wetlands ◽  
Natural Environments ◽  
Carbon Addition ◽  
Soil Slurry ◽  
The Sanjiang Plain

The progress of dissimilatory iron(III) reduction is widespread in natural environments, particularly in anoxic habitats; in fact, wetland ecosystems are considered as “hotspots” of dissimilatory Fe(III) reduction. In this study, we conducted soil slurry and microbial inoculation anaerobic incubation with glucose, pyruvate, and soluble quinone anthraquinone-2,6-disulphonate (AQDS) additions in freshwater marsh and meadow wetlands in the Sanjiang Plain, to evaluate the role of carbon addition in the rates and dynamics of iron reduction. Dissimilatory Fe(III) reduction in marsh wetlands responded more quickly and showed twice the potential for Fe(III) reduction as that in meadow wetland. Fe(III) reduction rate in marsh and meadow wetlands was 76% and 30%, respectively. Glucose had a higher capacity to enhance Fe(III) reduction than pyruvate, which provides valuable information for the further isolation of Fe reduction bacteria in pure culture. AQDS could dramatically increase potential Fe(III) reduction as an electron shuttle in both wetlands. pH exhibited a negative relationship with Fe(III) reduction. In view of the significance of freshwater wetlands in the global carbon and iron cycle, further profound research is now essential and should explore the enzymatic mechanisms underlying iron reduction in freshwater wetlands.

Carbon exchange in a freshwater marsh in the Sanjiang Plain, northeastern China

2011 ◽  
Vol 151 (8) ◽  
pp. 1131-1138 ◽  
Author(s):  
Changchun Song ◽  
Li Sun ◽  
Yao Huang ◽  
Yuesi Wang ◽  
Zhongmei Wan
Keyword(s):  
Sanjiang Plain ◽  
Northeastern China ◽  
Freshwater Marsh ◽  
Carbon Exchange ◽  
The Sanjiang Plain

scholarly journals Application of Scenario Analysis and Multiagent Technique in Land-Use Planning: A Case Study on Sanjiang Wetlands

2013 ◽  
Vol 2013 ◽  
pp. 1-10
Author(s):  
Huan Yu ◽  
Shi-Jun Ni ◽  
Bo Kong ◽  
Zheng-Wei He ◽  
Cheng-Jiang Zhang ◽  
...  
Keyword(s):  
Land Use ◽  
Scenario Analysis ◽  
Land Use Planning ◽  
Simulation Models ◽  
Sanjiang Plain ◽  
Freshwater Wetlands ◽  
The Sanjiang Plain ◽  
Qualitative And Quantitative ◽  
Study Results

Land-use planning has triggered debates on social and environmental values, in which two key questions will be faced: one is how to see different planning simulation results instantaneously and apply the results back to interactively assist planning work; the other is how to ensure that the planning simulation result is scientific and accurate. To answer these questions, the objective of this paper is to analyze whether and how a bridge can be built between qualitative and quantitative approaches for land-use planning work and to find out a way to overcome the gap that exists between the ability to construct computer simulation models to aid integrated land-use plan making and the demand for them by planning professionals. The study presented a theoretical framework of land-use planning based on scenario analysis (SA) method and multiagent system (MAS) simulation integration and selected freshwater wetlands in the Sanjiang Plain of China as a case study area. Study results showed that MAS simulation technique emphasizing quantitative process effectively compensated for the SA method emphasizing qualitative process, which realized the organic combination of qualitative and quantitative land-use planning work, and then provided a new idea and method for the land-use planning and sustainable managements of land resources.

scholarly journals Levels, Inventory, and Risk Assessment of Heavy Metals in Wetland Ecosystem, Northeast China: Implications for Snow Cover Monitoring

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2161
Author(s):  
Fuxiang Zhang ◽  
Bo Meng ◽  
Shang Gao ◽  
Rupert Hough ◽  
Peng Hu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Snow Cover ◽  
Environmental Quality ◽  
Regional Scale ◽  
Class Ii ◽  
Sanjiang Plain ◽  
Preliminary Evaluation ◽  
Monitoring Method ◽  
The Sanjiang Plain ◽  
Water Pollution Index

Snow cover is a unique environmental medium in cold regions that can cause potential risks to the ecological environment, due to the release of pollutants that are stored in it. In this study, the Qixing River wetland, located in the Sanjiang Plain of China, was taken as the target research area. Heavy metals in snow cover, including Cu, Ni, Cr, Cd, Pb, and Zn were measured at 19 sampling sites. The results showed that the average concentrations of heavy metals were: Zn (103.46 ± 39.16) > Pb (13.08 ± 4.99) > Cr (11.97 ± 2.82) > Ni (9.55 ± 4.96) > Cu (6.19 ± 1.79) > Cd (0.55 ± 0.25) μg·L−1. Cr and Zn were between Class I and Class II in the “Environmental Quality Standards for Surface Water” of China (GB3838-2002). Pb in snow exceeded the upper limit of Class II, and was significantly higher than concentrations measured in water samples from the Qixing River wetland (p < 0.05), indicating that atmospheric deposition during winter was the major source of Pb. The water pollution index (WPI) indicated that 61.0% of samples could be considered of “clean” status, while the contribution of Zn, Pb, and Cr to WPI were 33.3%, 21.0%, and 19.3%, respectively. A preliminary evaluation of heavy metal inventory in snow cover showed that the residue level of Zn was the highest (2313.57 ± 1194.67 μg·m−2), while Cd was the lowest (13.91 ± 10.45 μg·m−2). The areas with high residues of heavy metals were all located near the buffer zone of the wetland (except for Zn), where snow depth tended to be greatest. Exposure analysis indicated that the risks to winter resident birds from snow ingestion was minimal, but it should be noted that the exposure risk was higher in birds with lower bodyweights. This study provides important information and scientific knowledge on the pollution characteristics and residue inventory of heavy metals in wetland ecosystems, while the results can also provide a monitoring method, reflecting atmospheric environmental quality at a local or regional scale.

scholarly journals Simulating Land-Use Changes and Predicting Maize Potential Yields in Northeast China for 2050

2021 ◽  
Vol 18 (3) ◽  
pp. 938
Author(s):  
Luoman Pu ◽  
Jiuchun Yang ◽  
Lingxue Yu ◽  
Changsheng Xiong ◽  
Fengqin Yan ◽  
...  
Keyword(s):  
Land Use ◽  
Food Security ◽  
Northeast China ◽  
Land Use Changes ◽  
Sanjiang Plain ◽  
Potential Production ◽  
Potential Yield ◽  
The Sanjiang Plain ◽  
Ecological Zones ◽  
The Future

Crop potential yields in cropland are the essential reflection of the utilization of cropland resources. The changes of the quantity, quality, and spatial distribution of cropland will directly affect the crop potential yields, so it is very crucial to simulate future cropland distribution and predict crop potential yields to ensure the future food security. In the present study, the Cellular Automata (CA)-Markov model was employed to simulate land-use changes in Northeast China during 2015–2050. Then, the Global Agro-ecological Zones (GAEZ) model was used to predict maize potential yields in Northeast China in 2050, and the spatio-temporal changes of maize potential yields during 2015–2050 were explored. The results were the following. (1) The woodland and grassland decreased by 5.13 million ha and 1.74 million ha respectively in Northeast China from 2015 to 2050, which were mainly converted into unused land. Most of the dryland was converted to paddy field and built-up land. (2) In 2050, the total maize potential production and average potential yield in Northeast China were 218.09 million tonnes and 6880.59 kg/ha. Thirteen prefecture-level cities had maize potential production of more than 7 million tonnes, and 11 cities had maize potential yields of more than 8000 kg/ha. (3) During 2015–2050, the total maize potential production and average yield decreased by around 23 million tonnes and 700 kg/ha in Northeast China, respectively. (4) The maize potential production increased in 15 cities located in the plain areas over the 35 years. The potential yields increased in only nine cities, which were mainly located in the Sanjiang Plain and the southeastern regions. The results highlight the importance of coping with the future land-use changes actively, maintaining the balance of farmland occupation and compensation, improving the cropland quality, and ensuring food security in Northeast China.

scholarly journals Enhancement of iron toxicity in L929 cells by d-glucose: accelerated(re-)reduction

2002 ◽  
Vol 368 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Ilka LEHNEN-BEYEL ◽  
Herbert de GROOT ◽  
Ursula RAUEN
Keyword(s):  
Ethyl Ester ◽  
Iron Reduction ◽  
Cell Damage ◽  
Reduction Rate ◽  
Fold Increase ◽  
Iron Complex ◽  
Iron Toxicity ◽  
Intracellular Iron ◽  
Iron Valence ◽  
Iron Pool

It has recently been shown that an increase in the cellular chelatable iron pool is sufficient to cause cell damage. To further characterize this kind of injury, we artificially enhanced the chelatable iron pool in L929 mouse fibroblasts using the highly membrane-permeable complex Fe(III)/8-hydroxyquinoline. This iron complex induced a significant oxygen-dependent loss of viability during an incubation period of 5h. Surprisingly, the addition of d-glucose strongly enhanced this toxicity whereas no such effect was exerted by l-glucose and 2-deoxyglucose. The assumption that this increase in toxicity might be due to an enhanced availability of reducing equivalents formed during the metabolism of d-glucose was supported by NAD(P)H measurements which showed a 1.5—2-fold increase in the cellular NAD(P)H content upon addition of d-glucose. To assess the influence of this enhanced cellular reducing capacity on iron valence we established a new method to measure the reduction rate of iron based on the fluorescent iron(II) indicator PhenGreen SK. We could show that the rate of intracellular iron reduction was more than doubled in the presence of d-glucose. A similar acceleration was achieved by adding the reducing agents ascorbate and glutathione (the latter as membrane-permeable ethyl ester). Glutathione ethyl ester, as well as the thiol reagent N-acetylcysteine, also caused a toxicity increase comparable with d-glucose. These results suggest an enhancement of iron toxicity by d-glucose via an accelerated (re-)reduction of iron with NAD(P)H serving as central electron provider and ascorbate, glutathione or possibly NAD(P)H itself as final reducing agent.

Microbial CO2 production from surface and subsurface soil as affected by temperature, moisture, and nitrogen fertilisation

Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 273 ◽  
Author(s):  
Xiaobin Jin ◽  
Shenmin Wang ◽  
Yinkang Zhou
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Sanjiang Plain ◽  
Co2 Production ◽  
The Sanjiang Plain ◽  
Subsurface Soil ◽  
C Mineralisation ◽  
Q10 Values

The Sanjiang Plain of north-east China is presently the second largest freshwater marsh in China. The drainage and use of marshes for agricultural fields occurred in the past 50 years, resulting in the increase in cultivated land from about 2.9 × 108 m2 in 1893 to 4.57 × 1010 m2 in 1994. Under human disturbance in the past half century, the environment in Sanjiang Plain has had significant change. We hypothesised that environmental factors such as soil moisture, soil temperature, and soil N levels affect the rates of soil organic C mineralisation and the nature of the controls on microbial CO2 production to change with depth through the soil profile in the freshwater marsh in the Sanjiang Plain. In a series of experiments, we measured the influence of soil temperature, soil water content, and nitrogen additions on soil microbial CO2 production rates. The results showed that Q10 values (the factor by which the CO2 production rate increases when the temperature is increased by 10°C) significantly increased with soil depth through the soil profile (P < 0.05). The average Q10 values for the surface soils were 2.7 (0–0.2 m), significantly lower than that (average Q10 values 3.3) for the subsurface samples (0.2–0.6 m) (P < 0.05), indicating that C mineralisation rates were more sensitive to temperature in subsurface soil horizons than in surface horizons. The maximum respiration rate was measured at 60% water hold capacity for each sample. The quadratic equation function adequately describes the relationship between soil respiration and soil water content, and the R2 values were > 0.80. The sensitivity of microbial CO2 production rate response to soil water content for surface soils (0–0.2 m) was slightly lower than for subsurface soils (0.2–0.6 m). The responses of actual soil respiration rates to nitrogen fertilisation were different for surface and subsurface soils. In the surface soils (0–0.2 m), the addition of N caused a slight decreased in respiration rates compared with the control, whereas, in the subsurface soils (0.2–0.6 m), the addition of N tended to increase microbial CO2 production rates, and the addition of 10 µg N/g soil treatment caused twice the increase in C mineralisation rates of the control. Our results suggested that the responses of microbial CO2 production to changes in soil moisture, soil temperature, and soil N levels varied with soil depth through the profile, and subsurface soil organic C was more sensitive to temperature increase and nitrogen inputs in the freshwater marsh of the Sanjiang Plain.

Ecosystem-atmosphere exchange of CO2 in a temperate herbaceous peatland in the Sanjiang Plain of northeast China

2015 ◽  
Vol 75 ◽  
pp. 16-23 ◽  
Author(s):  
Xiaoyan Zhu ◽  
Changchun Song ◽  
Christopher Martin Swarzenski ◽  
Yuedong Guo ◽  
Xinhou Zhang ◽  
...  
Keyword(s):  
Northeast China ◽  
Sanjiang Plain ◽  
The Sanjiang Plain
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