The Experts below are selected from a list of 8883 Experts worldwide ranked by ideXlab platform
Krishna R Reddy - One of the best experts on this subject based on the ideXlab platform.
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temperature sensitivity of greenhouse gas production in Wetland Soils of different vegetation
Biogeochemistry, 2012Co-Authors: Kanika S Inglett, Krishna R Reddy, Patrick W Inglett, Todd Z OsborneAbstract:Organic matter decomposition regulates rates of carbon loss (CO2 and CH4) in Wetlands and has implications for carbon sequestration in the context of changing global temperature. Here we determined the influence of temperature and vegetation type on both aerobic and anaerobic decomposition of organic matter in subtropical Wetland Soils. As in many other studies, increased temperature resulted in higher rates of respiration and methanogenesis under both aerobic and anaerobic conditions, and the positive effect of temperature depended on vegetation (source of carbon substrate to soil). Under anaerobic incubations, the proportion of gaseous C (CO2 and CH4) lost as CH4 increased with temperature indicating a greater sensitivity of methanogenesis to temperature. This was further supported by a wider range of Q10 values (1.4–3.6) for methane production as compared with anaerobic CO2 (1.3–2.5) or aerobic CO2 (1.4–2.1) production. The increasing strength of positive linear correlation between CO2:CH4 ratio and the soil organic matter ligno-cellulose index at higher temperature indicated that the temperature sensitivity of methanogenesis was likely the result of increased C availability at higher temperature. This information adds to our basic understanding of decomposition in warmer subtropical and tropical Wetland systems and has implications for C models in Wetlands with different vegetation types.
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soil phosphorus flux from emergent marsh Wetlands and surrounding grazed pasture uplands
Ecological Engineering, 2010Co-Authors: E J Dunne, Mark W Clark, Jennifer Mitchell, James W Jawitz, Krishna R ReddyAbstract:Abstract Phosphorus (P) release from Wetland Soils to overlying waters is important to consider when restoring Wetland hydrology. Soil physicochemical characteristics influence P dynamics between underlying soil and overlying water. Our study initially characterized Wetland and surrounding upland Soils prior to flooding. Deep marsh Wetland Soils had greater moisture content, soil organic matter, nitrogen (N), P, and lower bulk density than surrounding upland pasture Soils, which indicates a nutrient concentration gradient between Wetland and upland Soils. To determine the short-term P dynamics between Soils and overlying water, we conducted four laboratory soil water core studies during a 15-month period. Surface Soils (0-10 cm) collected October 2005, February 2006, October 2006 and December 2006 from Wetlands and their surrounding uplands within cow-calf grazed pastures were flooded for 7 days, and we measured P release from soil to overlying water. Phosphorus release rates from Wetland (deep marsh and shallow marsh) and upland Soils were similar. Values ranged between −20 mg m −2 d −1 (retention) and 77 mg m −2 d −1 (release). There was a significant, although weak, negative linear relationship between P release from deep marsh Soils and hydroperiod. Thus, it may be important for land managers to consider increasing hydroperiod of Wetland Soils to decrease P release and increase retention. In addition, there was a significant negative exponential relationship between P release and days since deep marsh soil inundation. This suggests that to decrease P release from Soils, Soils should be wet rather than dry for prolonged periods, prior to flooding. We found significant relationships between P release from upland Soils and their nutrient content (N, P and carbon). Reducing nutrient content in upland Soils may help reduce the magnitude of P release from soil.
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Heterotrophic Microbial Activity in Northern Everglades Wetland Soils
Soil Science Society of America Journal, 2001Co-Authors: Alan L Wright, Krishna R ReddyAbstract:Phosphorus loading to the northern Florida Everglades has been implicated in causing changes in vegetation, peat accretion rates, and other soil physical-chemical properties. Our study focused on determining the influence of P loading on aerobic and anaerobic heterotrophic microbial activities (measured as CO 2 and CH 4 production) in detritus and soil collected from the Water Conservation Area 2a (WCA-2a) of the Everglades. Heterotrophic microbial activities measured under both field and laboratory conditions were higher in areas impacted by P loading as compared to the unimpacted interior marsh. Microbial heterotrophic activities were higher in detritus and surface Soils and decreased with depth. In field studies, CO 2 production rates in anaerobic Soils were approximately 64% of those observed in aerobic Soils. Additions of substrates containing C, N, and P generally enhanced heterotrophic microbial activity. In laboratory studies involving addition of various inorganic electron acceptors, increased microbial activities in the order of O - 2 > NO - 3 = SO 2- 4 > HCO - 3 were observed. Microbial CO 2 production rates under denitrifying and sulfate reducing conditions ranged from 30-42% and 29-44%, respectively, of aerobic rates. Methane production rates were only up to 9% of aerobic CO 2 production rates. Both CO 2 and CH 4 production rates were significantly correlated with soil P parameters and microbial biomass. Enhanced heterotrophic microbial activities resulting from P loading has the potential to increase turnover of organic matter which may lead to increased supply of bioavailable nutrients to emergent macrophytes and periphyton and higher nutrient concentrations in the water column.
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phosphorus flux from Wetland Soils affected by long term nutrient loading
Journal of Environmental Quality, 2001Co-Authors: M M Fisher, Krishna R ReddyAbstract:Wetland Soils play a key role in the cycling of nutrients within an ecosystem. Since Soils are potentially a source or a sink for inorganic nutrients, it is important to quantify their influence on overlying water quality in order to understand their importance in overall ecosystem nutrient budgets. Laboratory and field studies were performed in the northern Everglades (WCA-2A) to determine the magnitude of phosphorus (P) flux between the soil and the overlying water column, under various redox conditions. The P flux was estimated using three techniques: intact soil cores, in situ benthic chambers, and porewater equilibrators. There was reasonable agreement between the P flux estimated using intact soil cores and benthic chambers; however, P flux estimates using the porewater equilibrators were considerably lower than the other two techniques. Models of solute flux, based solely on soil physico-chemical characteristics, may substantially underestimate soil-water nutrient exchange processes. Phosphorus flux measured with the intact soil cores varied from 6.5 mg m -2 d -1 near nutrient inflow areas to undetectable flux 4 km away from the inflow. Oxygen consumption varied from 4 mg m -2 d -1 near the inflow to a constant 1 to 2 mg m -2 d -1 at a distance of 4 km from the inflow. Rate of consumption of NO 3 - -N and SO 4 2- showed no significant trend with respect to distance from inflow. Nitrate N and SO, consumption rates averaged 120 and 130 mg m -2 d -1 , respectively. Consumption of O 2 was correlated with P flux, whereas NO 3 - -N and SO 4 2- consumption were not.
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Regulators of heterotrophic microbial potentials in Wetland Soils
Soil Biology & Biochemistry, 1999Co-Authors: Elisa D’angelo, Krishna R ReddyAbstract:Potential rates of aerobic respiration, denitrification, sulfate reduction and methanogenesis were investigated in 10 different Wetland Soils with a wide range of biogeochemical characteristics, with the objective of determining relationships between process rates and soil properties. Electron acceptor amendments to methanogenic Soils caused gradual (1–13 d) to immediate transitions in electron flow from methanogenesis to alternate electron acceptors. Rates of organic C mineralization ranged between 0.2 and 34 μmol C g−1 d−1 and averaged three times faster with O2 as compared to alternate electron acceptors. There was no significant difference between rates of organic C mineralization (CO2+CH4 production) under denitrifying, sulfate-reducing and methanogenic conditions, indicating that soil organic carbon availability was similar under the different anaerobic conditions. Rates of electron acceptor consumption ranged between 1 and 107 μmol g−1 d−1 for O2, 0.5 and 9.3 μmol g−1 d−1 for NO3−, 0.1 and 11.1 μmol g−1 d−1 for SO42− and 0.1 and 6.2 μmol g−1 d−1 for CO2. Heterotrophic potentials in Wetland Soils were strongly correlated with inorganic N and several available C indices (total, dissolved and microbial C), but not with pH or dissolved nutrients (P, Ca2+, Mg2+, Fe(II)). Microbial activity–soil property relationships determined in this study may be useful for predicting the fate of pollutants that are influenced by microbial oxidation–reduction reactions in different types of Wetland Soils.
Ming Jiang - One of the best experts on this subject based on the ideXlab platform.
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unexpected high methylmercury contents related to soil organic carbon and its molecular composition in Wetland Soils of the yarlung tsangbo river tibet
Geoderma, 2020Co-Authors: Zhongsheng Zhang, Zhenshan Xue, Ming JiangAbstract:Abstract Deciphering the role of soil organic matter on methylmercury production in Wetlands is an important environmental topic in Tibet, where is the province with the largest number of international rivers, including the Yarlung Tsangbo River. In this study, total mercury (THg) and methylmercury (MeHg) contents in Soils from Wetlands along the YTR were detected, and roles of the molecular composition of soil organic carbon (SOC) in the formation of MeHg were explained in detail by pyrolysis–gas chromatography/mass spectrometry technology (Py-GC/MS). On average, THg and MeHg contents were 62.9 ng/g and 5.88 ng/g, respectively. About 12.6% of total Hg was in the form of MeHg. Unexpected high methylmercury levels occurred in Wetland Soils along the YTR. The topSoils (0–20 cm) had more THg but less MeHg contents than those in subSoils (20–48 cm). The proportion of MeHg to THg (RHg) was higher in subSoils than in topSoils independent of Wetland types. Correlations between THg, MeHg, and SOC were weak in topSoils but strong in subSoils. Lignin and phenol moieties of SOC pyrolysis products were significantly and positively related to THg in topSoils, while positive or negative correlations were found between THg, MeHg, and pyrolysis products of SOC in subSoils at p
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identification of anthropogenic contributions to heavy metals in Wetland Soils of the karuola glacier in the qinghai tibetan plateau
Ecological Indicators, 2019Co-Authors: Zhongsheng Zhang, Zhenshan Xue, Dongmei Zheng, Ming JiangAbstract:Abstract Deciphering apportionments of natural and anthropogenic sources to metal concentrations are essential for better understanding impacts of human activities on metal element distribution in remote alpine Wetlands. In the present work, we investigated heavy metal distribution patterns and identified the substantial contributions from anthropogenic sources on heavy metal concentrations in Wetland Soils of the Karuola Glacier in Tibet using a geochemical model and lead isotopes. Mean iron (Fe), aluminum (Al), and scandium (Sc) concentrations were similar to their background values and manganese (Mn) was lower than that. Concentrations of copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), and chromium (Cr) were much higher than their background values. Cd was the main contaminant because more than 87.7% of Cd was anthropogenic. Al, Pb, and Sc showed significant positive correlations between each other, Cr and Mn concentrations were significantly and negatively correlated with Fe concentrations. No significant correlations were observed among Fe, Pb, Cu, Cd, and Zn. Three components were extracted by factor analysis. Al, Fe, Sc, Cr, and Mn were related primarily to the parent material, Pb in Soils was from both endogenous and exogenous sources, and Cd, Zn, and Cu were considerably or mostly from anthropogenic sources. Endogenous sources represented about 59.85%–81%, 69.3%, 12.3%, and 58.1% for total Pb, Cu, Cd, and Zn in Soils. Metal accumulation fluxes have been increasing over the past 200 years. Lead isotopic features showed that most anthropogenic Pb was attributed to Pb-Zn ore smelting and coal consumption.
Zhongsheng Zhang - One of the best experts on this subject based on the ideXlab platform.
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unexpected high methylmercury contents related to soil organic carbon and its molecular composition in Wetland Soils of the yarlung tsangbo river tibet
Geoderma, 2020Co-Authors: Zhongsheng Zhang, Zhenshan Xue, Ming JiangAbstract:Abstract Deciphering the role of soil organic matter on methylmercury production in Wetlands is an important environmental topic in Tibet, where is the province with the largest number of international rivers, including the Yarlung Tsangbo River. In this study, total mercury (THg) and methylmercury (MeHg) contents in Soils from Wetlands along the YTR were detected, and roles of the molecular composition of soil organic carbon (SOC) in the formation of MeHg were explained in detail by pyrolysis–gas chromatography/mass spectrometry technology (Py-GC/MS). On average, THg and MeHg contents were 62.9 ng/g and 5.88 ng/g, respectively. About 12.6% of total Hg was in the form of MeHg. Unexpected high methylmercury levels occurred in Wetland Soils along the YTR. The topSoils (0–20 cm) had more THg but less MeHg contents than those in subSoils (20–48 cm). The proportion of MeHg to THg (RHg) was higher in subSoils than in topSoils independent of Wetland types. Correlations between THg, MeHg, and SOC were weak in topSoils but strong in subSoils. Lignin and phenol moieties of SOC pyrolysis products were significantly and positively related to THg in topSoils, while positive or negative correlations were found between THg, MeHg, and pyrolysis products of SOC in subSoils at p
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identification of anthropogenic contributions to heavy metals in Wetland Soils of the karuola glacier in the qinghai tibetan plateau
Ecological Indicators, 2019Co-Authors: Zhongsheng Zhang, Zhenshan Xue, Dongmei Zheng, Ming JiangAbstract:Abstract Deciphering apportionments of natural and anthropogenic sources to metal concentrations are essential for better understanding impacts of human activities on metal element distribution in remote alpine Wetlands. In the present work, we investigated heavy metal distribution patterns and identified the substantial contributions from anthropogenic sources on heavy metal concentrations in Wetland Soils of the Karuola Glacier in Tibet using a geochemical model and lead isotopes. Mean iron (Fe), aluminum (Al), and scandium (Sc) concentrations were similar to their background values and manganese (Mn) was lower than that. Concentrations of copper (Cu), cadmium (Cd), lead (Pb), zinc (Zn), and chromium (Cr) were much higher than their background values. Cd was the main contaminant because more than 87.7% of Cd was anthropogenic. Al, Pb, and Sc showed significant positive correlations between each other, Cr and Mn concentrations were significantly and negatively correlated with Fe concentrations. No significant correlations were observed among Fe, Pb, Cu, Cd, and Zn. Three components were extracted by factor analysis. Al, Fe, Sc, Cr, and Mn were related primarily to the parent material, Pb in Soils was from both endogenous and exogenous sources, and Cd, Zn, and Cu were considerably or mostly from anthropogenic sources. Endogenous sources represented about 59.85%–81%, 69.3%, 12.3%, and 58.1% for total Pb, Cu, Cd, and Zn in Soils. Metal accumulation fluxes have been increasing over the past 200 years. Lead isotopic features showed that most anthropogenic Pb was attributed to Pb-Zn ore smelting and coal consumption.
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ecological stoichiometry of carbon nitrogen and phosphorus in estuarine Wetland Soils influences of vegetation coverage plant communities geomorphology and seawalls
Journal of Soils and Sediments, 2013Co-Authors: Zhongsheng Zhang, Xiaolin Song, Zhenshan XueAbstract:Little is known about carbon, nitrogen, and phosphorus stoichiometrical characteristics and influencing factors in estuary Wetland Soils. The purpose of this work is to study ecological stoichiometric characteristics of carbon, nitrogen, and phosphorus (R CN, R CP, and R NP) in estuarine Wetland Soils of Shuangtaizi, northeast China and the potential affecting factors like vegetation coverage, plant communities, geomorphology, and seawall. During 2008–2010, soil samples in estuarine Wetland were collected for soil organic carbon, total nitrogen and phosphorus, and other elements determination. Mole ratios of R CN, R CP, and R NP were calculated. As a whole, R CN was in the range of 8.26∼52.97 (mean, 16.15), R CP was in the range of 23.21∼862.53 (mean, 90.66), and R NP was in the 0.93∼29.52 (mean, 5.07). R CN, R CP, and R NP distribution were all with high spatial heterogeneities and significantly affected by vegetation coverage, plant communities, geomorphology, and seawalls. During the typical plant succession sequence of the halophytes–the mesophyte–the hydrophyte in estuarine Wetland, P might be the primary limiting elements for nutrients stoichiometrical characteristics. R CN, R CP, and R NP in Soils of low-lying areas were all higher than that in highlands. Plant coverage and communities formation would help to reduce restriction from nitrogen, but to increase restrictions from phosphorus meanwhile. C, N, and P ecological stoichiometry had high complexities. R CN in estuarine Wetland Soils were generally high, whereas R CP and R NP were comparatively low, indicating that ecosystems in the estuary were limited by nutrients such as N and P, with the latter being the primary factor. Vegetation covers, plant communities, geomorphology, and seawall all affected nutrient stoichiometry in Soils.
Junhong Bai - One of the best experts on this subject based on the ideXlab platform.
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desalinization via freshwater restoration highly improved microbial diversity co occurrence patterns and functions in coastal Wetland Soils
Science of The Total Environment, 2021Co-Authors: Laibin Huang, Guangliang Zhang, Junhong Bai, Zhijian Xia, Wei Wang, Jia Jia, Xin Wang, Xinhui Liu, Baoshan CuiAbstract:Abstract Saltwater intrusion has greatly impacted the functions of coastal Wetland Soils worldwide by increasing the salt stress; desalinization via freshwater restoration has been suggested to recover saline Wetland Soils and biodiversity, but its effectiveness is debated. To evaluate the desalinization effectiveness, we characterized the microbial communities and activities using high throughput 16S rRNA gene sequencing and 15N isotopic techniques in freshwater restored (≥10 years) and unrestored Wetlands, and then compared the data with reported values of original freshwater Wetlands in one of the most dynamic coastal areas, Yellow river estuary (YRE). Our data revealed that freshwater input significantly increased the soil organic carbon (SOC; P Originality-significance statement Salinization is globally spreading with approximately one billion hectares area covered with saline and/or sodic Soils on the earth, and the negative effects of salinity on soil microbial communities and their activities have been frequently reported in previous studies all around the world; however, it remains largely unknown about whether the microbial communities and their activities can be recovered or not in soil suffered salinization. Desalinization via freshwater restoration is supposed to offer a good solution to soil salinization in coastal area, but the effectiveness is debated. Here, we are presenting the long-term of field study related to the desalinization effects on microbial diversity, co-occurrence and functions, and find desalinization via freshwater restoration can recover most of microbial communities up to the similar levels of that in original freshwater Wetlands, and highly improved microbial diversity and their functions, which sheds a positive light on soil desalinization via freshwater restoration at microenvironments.
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heavy metals in Wetland Soils along a Wetland forming chronosequence in the yellow river delta of china levels sources and toxic risks
Ecological Indicators, 2016Co-Authors: Guangliang Zhang, Junhong Bai, Jia Jia, Qingqing Zhao, Xiaojun WenAbstract:Abstract Surface soil (0–20 cm) samples were collected from four chronological sequences of Wetlands (i.e., >50-yr-old Wetlands, 40-yr-old Wetlands, 30-yr-old Wetlands and 10-yr-old Wetlands) in the Yellow River Delta of China in May and June of 2007. Total contents of Al, As, Cd, Cr, Cu, Ni, Pb and Zn were determined using inductively coupled plasma atomic absorption spectrometry (ICP-AAS) to investigate the levels, sources and toxic risks of heavy metals in these Wetlands. Our results showed an increasing trend for Pb, Cu and Zn along the Wetland-forming chronosequence although their pollution levels were low. Both As and Cd exhibited significant enrichment due to their high enrichment factor (EF) values (EF > 5), especially in older Wetlands (i.e., >50-yr-old and 40-yr-old Wetlands), whereas other heavy metals were minimally or moderately enriched in this region. The results of principal component analysis showed that 83.09% of total variance based on eigenvalues (eigenvalue > 1) could be explained by three principal components (PCs) in four Wetlands. The source of Al, Cu, Pb and Zn was different from Cd, Cr and Ni. According to the sediment quality guidelines (SQGs) of China, soil samples in the younger Wetlands, especially the 10-yr-old Wetlands, were moderately polluted by As, Cd and Ni. According to the SQGs of US EPA, all soil samples were heavily polluted by As and moderately polluted by Ni and soil samples in the older Wetlands were moderately polluted by Cr. However, with the exception of As and Ni, the contents of other heavy metals in the four Wetlands did not exceed the probable effect level (PEL) values. As, Cd and Ni were identified as heavy metals of primary concerns in four Wetlands, Cr were of moderate concern in older Wetlands, and Pb, Cu and Zn should be paid more attention in younger Wetland (i.e., 10-yr-old and 30-yr-old Wetlands). A new and sensitive toxic risk index (TRI) is developed for the accurate assessment of toxic risk for heavy metals in Wetland Soils compared with the sum of the toxic units (∑TUs), and As, Cr, Ni and Cd showed higher contributions to TRI.
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levels sources and risk assessment of trace elements in Wetland Soils of a typical shallow freshwater lake china
Stochastic Environmental Research and Risk Assessment, 2013Co-Authors: Haifeng Gao, Junhong Bai, Rong Xiao, Peipei Liu, Wei Jiang, Junjing WangAbstract:The deteriorating environmental conditions of Baiyangdian Lake have caused a wide public concern. Surface Soils (0–20 cm) were collected at 10 sites of reed Wetlands in raised fields of the Baiyangdian Lake. They were analyzed for total contents of trace elements to investigate their distribution and pollution levels in Wetland Soils of this region. Results showed that the mean contents of As, Cd, Cr, Cu, Ni, Pb and Zn all exceeded their environmental background values of Hebei Province and had various degree of spatial variations. As, Cr and Ni contents exceeded considerably the probable effect levels. Multivariate analysis indicated that Cr, Cd, Ni, Cu, Pb and Zn had common sources and As had different sources for these trace elements. The average toxic units (TU) of trace elements in the Baiyangdian Lake followed the order As > Ni > Cr > Zn > Pb > Cu > Cd. As, Ni and Cr made the higher contributions to ΣTUs (i.e., 41.3 ± 7.2, 21.8 ± 4.1 and 16.2 ± 2.8 %, respectively). The potential ecological risk index of Cd $$ \left( {E_{r}^{i} } \right) $$ was 213.44, which was the highest value in the Baiyangdian Lake. The other trace elements had lower potential ecological risk indices ( As > Cu > Pb = Ni > Cr > Zn. Potential toxicity response indices (RI) of trace elements for the whole lake region was 269.81, with a moderate potential toxicity response.
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contamination characteristics of heavy metals in Wetland Soils along a tidal ditch of the yellow river estuary china
Stochastic Environmental Research and Risk Assessment, 2011Co-Authors: Junhong Bai, Laibin Huang, Haifeng Gao, Denghua Yan, Qinggai Wang, Rong Xiao, Chen HuangAbstract:Surface Soils (0–20 cm) were collected from along a tidal ditch of the Yellow River Estuary in August of 2007. Samples were subjected to a total digestion technique before they were analyzed for total concentrations of As, Cr, Cd, Cu, Ni, Pb, Zn, P and S in order to investigate heavy metal contamination levels in Wetland Soils nearby the tidal ditches and their main sources. Results showed that the mean concentrations of these heavy metals except for As and Cd were lower than the Class I criteria. Nearly all sampling sites showed lower contamination levels for As and Cd, while no contamination levels for other heavy metals. Cr, Cu, and Ni mainly originated from parent rocks, and Pb and As might originate from tidal seawater and oil field pollution, respectively; while Cd and Zn mainly originated from parent rocks and tidal seawater. Most of heavy metals showed significant correlations with total concentrations of P and S, however, no significant correlations were observed between them and soil pH, slat and soil organic matter.
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some heavy metals distribution in Wetland Soils under different land use types along a typical plateau lake china
Soil & Tillage Research, 2010Co-Authors: Junhong Bai, Baoshan Cui, Zhifeng Yang, Haifeng Gao, Qiuyi DingAbstract:Abstract Topsoil (0–20 cm) samples were collected from three sampling plots under different land use types (uncultivated Wetland, cultivated Wetland and cultivated Wetland after abandonment) along the eastern region of the Yilong Lake in October, 2005. Total concentrations of As, Cd, Cu, Pb and Zn were determined using the inductively coupled plasma atomic absorption spectrometry in order to assess and compare contamination levels of the three sampling plots. Results showed that the average concentrations of these heavy metals were generally higher in Wetland Soils and abandoned tilled Soils than those in conventionally tilled Soils. Compared with Wetland Soils, contamination indices were lower for As and Cd in conventionally tilled Soils, as well as lower for As in abandoned tilled Soils, while no significant differences were observed for other heavy metals. The integrated contamination indices showed low contamination levels for cultivated Soils, and high contamination levels for Wetland Soils and abandoned tilled Soils.
Hongbo Shao - One of the best experts on this subject based on the ideXlab platform.
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potential retention and release capacity of phosphorus in the newly formed Wetland Soils from the yellow river delta china
Clean-soil Air Water, 2012Co-Authors: Junna Sun, Hongbo ShaoAbstract:There are few researches on the characteristics of phosphorus (P) in the newly born Wetland Soils from Yellow River Delta of China. Meanwhile, whether the Wetland Soils can protect the aquatic ecosystem from excessive P input or not and the risk of P release from the Soils to the water quality have generated considerable interests. Through isothermal batch static equilibrium sorption experiments followed by six subsequent extraction steps, the present study assessed the variations in P sorption and desorption properties of the newly born Wetland Soils in Yellow River Delta. It is found that the P sorption isotherms were nonlinear and the amount of P sorption reached a steady state as P initial concentration added increased in the studied Soils. Though the capacity of P retention differed strongly among the studied zone, the Soils can protect the aquatic ecosystem from excessive P input to a certain extent degree. From the desorption experiments, it is found that the newly sorbed P was easily desorbed in higher initial added concentration and the desorption P significantly decreased with successive extraction in all samples. The release of P from soil proposed a significant contribution to the water quality and eutrophication of coastal zone. Correlation and regression analyses showed that the amorphous and free Fe/Al oxides, correlated with clay content in the studied Soils, were the crucial chemical factors ascribed to the soil P retention and release capacity.
