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Li Gao - One of the best experts on this subject based on the ideXlab platform.
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application of dgt difs and geochemical baseline to assess cd release risk in reservoir Riparian Soils china
Science of The Total Environment, 2019Co-Authors: Bo Gao, Wenqi Peng, Li Gao, Xiaohong WanAbstract:Abstract As the sole drinking water source for Beijing City, Cd has been previously assessed as the major contaminant in Miyun Reservoir (MYR) Riparian Soils. However, the potential release risk of Cd in such Soils, and the labile-Cd release–resupply process from the soil solid phase to solution after water impoundment remain poorly understood. We established a geochemical baseline concentration (GBC) of Cd in MYR Riparian Soils, combined with the diffusive gradient in thin films (DGT) technique and DGT-induced fluxes in soil (DIFS) model, to reveal a dynamic release–resupply process and influencing factors of labile Cd in Riparian Soils. The results showed that Cd GBC in Riparian Soils was 0.12 mg/kg, which was higher than the Cd background value (BV) for Beijing. Using Cd GBC as BV to assess the Cd contaminant level, the geo-accumulation index showed that Cd in Riparian Soils was at the uncontaminated level. In addition, Cd in the Soils belonged to the non-residual fraction using the Community Bureau of Reference method. Cd mobility coefficients (F1/CTotal-Cd) of Soils at low elevation had relatively high values, implying that Cd may be released during the initial impoundment of the MYR. Moreover, correlation analysis was used to found the major influencing factors between DGT-labile Cd and several parameters. The results showed that the DGT-labile Cd was positively correlated to the reducible and oxidizable fraction, CDGT-Fe, and total organic carbon, illustrating that the release of Cd from Soils was controlled by Fe oxides and organic matter. The resupply ability (R values) and DIFS model parameters revealed that Cd in MYR Soils belonged to the partially sustained case, and the slow desorption rate suggested that the release risk of Cd was low in the MYR Riparian Soils.
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assessing cu remobilization in reservoir Riparian Soils prior to water impoundment using dgt and geochemical fractionation
Geoderma, 2018Co-Authors: Haoran Sun, Bo Gao, Li Gao, Ke SunAbstract:Abstract As the world's largest water diversion project, the South-to-North Water Diversion Project in China will have potential environmental effects on the Miyun Reservoir (MYR). However, Cu is a toxic pollutant, and the potential risk of Cu remobilization in MYR Soils after water impoundment remains unknown. Riparian Soils (five land use types and three vertical elevations) were collected from the MYR before water impoundment. Soil properties, total concentrations of Cu in Soils (Ctotal-Cu) and pore water (Csol-Cu), and chemical fractions were measured. Diffusive gradients in thin films (DGT) and the DGT-induced fluxes in Soils (DIFS) model were applied to investigate Cu availability. The average Ctotal-Cu was higher than the Chinese background values, indicating potential anthropogenic input of Cu. No significant influences of land use types/vertical elevations on DGT-labile Cu (CDGT-Cu) and Ctotal-Cu were observed. A significant positive relationship between CDGT-Cu and Csol-Cu showed that CDGT-Cu can effectively predict bioavailable Cu fraction in MYR Soils, whereas CDGT-Cu had no correlation with different chemical fractions measured by European Community Bureau of Reference (BCR) geochemical fractionation, suggesting that BCR chemical fractions cannot reflect Cu mobility in MYR Soils. Risk assessment code showed a low risk of Cu remobilization in MYR Soils, but a reducing environment would cause higher mobilization of Cu associated with Fe/Mn oxides after water impoundment. Moreover, the DIFS model reported a deficient soil resupply capacity; this agreed with low R values, which were mostly attributed to the limited available pool of Cu in the soil solid phase.
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assessment of labile zn in reservoir Riparian Soils using dgt difs and sequential extraction
Ecotoxicology and Environmental Safety, 2018Co-Authors: Li Gao, Bo Gao, Wenqi Peng, Ke SunAbstract:Abstract The middle route of the South-to-North Water Diversion project alleviates drought in northern China, especially reducing water shortage pressure in Beijing. However, after submersion, the potential release risk of metals in newly submerged Soils into the water in the receiving reservoir remains unclear. Here, we assess the labile Zn in the Riparian Soils of Miyun Reservoir (MYR) using the diffusive gradients in thin films (DGT), DGT-induced fluxes in Soils (DIFS) model, and Community Bureau of Reference (BCR) sequential extraction. The results showed that the average Zn concentrations at three sampling sites (S2, S3, and S5) exceeded soil background value (74.8 mg/kg), indicative of Zn accumulation in the MYR. The concentrations of DGT-labile Zn varied within 39.7–62.4 μg/L (average: 56.7 μg/L), with the greatest value observed at 145 m at sampling site S3, attributed to anthropogenic activities in recreational areas. The DGT-labile Zn showed no correlation with classes of land, elevations, or soil properties. Sequential extraction results demonstrated that Zn predominantly existed in the residual fraction, but still showed a strong capability for resupply from the solid phase (R >1). The DIFS model simulation results showed that Zn underwent irreversible diffusion of intra-particle metals from the solid phase to the soil solution. Therefore, the potential release risk of labile Zn in Riparian Soils in MYR cannot be ignored, especially for areas experiencing human disturbance.
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predicting ni dynamic mobilization in reservoir Riparian Soils prior to water submergence using dgt and difs
Chemosphere, 2018Co-Authors: Li Gao, Bo Gao, Shuhua Yin, Jijun GaoAbstract:Abstract The South-to-North Water Diversion Project has been initiated to address the problem of water shortages in north China. However, the environmental impact of this project is currently unclear, especially for the geochemical process of toxic trace metals in reservoir Riparian soil following water submergence. The mobility of Ni in Miyun Reservoir Riparian soil samples was investigated using diffusive gradients in thin films (DGT), considering five different land use types and three vertical elevations. The DGT-induced fluxes in soil (DIFS) model was applied to simulate the kinetics of Ni mobilization in the soil. The results showed that the average concentration of Ni was 36.58 mg/kg, which was slightly higher than the corresponding background values reported for both Beijing and China. Coincidentally, the highest concentrations of both total Ni and DGT-labile Ni (CDGT-Ni) were observed at the same site (recreational area), indicating that anthropogenic activities may have contributed to the release of Ni. Land use type and vertical elevation had no significant influence on CDGT-Ni. In addition, CDGT-Ni was positively correlated with reducible fraction, CDGT-Fe, CDGT-Mn, and TOC, indicating that Ni in the Soils was adsorbed mainly on the Fe/Mn oxides and organic matter. Moreover, the low values of R (CDGT-Ni/Csol-Ni, R
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pollution characteristics and source identification of trace metals in Riparian Soils of miyun reservoir china
Ecotoxicology and Environmental Safety, 2017Co-Authors: Lanfang Han, Bo Gao, Li Gao, Yang Zhou, Ke SunAbstract:The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline Soils into Miyun Reservoir (MYR). Here, Riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206Pb/207Pb and 208Pb/207Pb values of Soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future.
Ke Sun - One of the best experts on this subject based on the ideXlab platform.
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assessing cu remobilization in reservoir Riparian Soils prior to water impoundment using dgt and geochemical fractionation
Geoderma, 2018Co-Authors: Haoran Sun, Bo Gao, Li Gao, Ke SunAbstract:Abstract As the world's largest water diversion project, the South-to-North Water Diversion Project in China will have potential environmental effects on the Miyun Reservoir (MYR). However, Cu is a toxic pollutant, and the potential risk of Cu remobilization in MYR Soils after water impoundment remains unknown. Riparian Soils (five land use types and three vertical elevations) were collected from the MYR before water impoundment. Soil properties, total concentrations of Cu in Soils (Ctotal-Cu) and pore water (Csol-Cu), and chemical fractions were measured. Diffusive gradients in thin films (DGT) and the DGT-induced fluxes in Soils (DIFS) model were applied to investigate Cu availability. The average Ctotal-Cu was higher than the Chinese background values, indicating potential anthropogenic input of Cu. No significant influences of land use types/vertical elevations on DGT-labile Cu (CDGT-Cu) and Ctotal-Cu were observed. A significant positive relationship between CDGT-Cu and Csol-Cu showed that CDGT-Cu can effectively predict bioavailable Cu fraction in MYR Soils, whereas CDGT-Cu had no correlation with different chemical fractions measured by European Community Bureau of Reference (BCR) geochemical fractionation, suggesting that BCR chemical fractions cannot reflect Cu mobility in MYR Soils. Risk assessment code showed a low risk of Cu remobilization in MYR Soils, but a reducing environment would cause higher mobilization of Cu associated with Fe/Mn oxides after water impoundment. Moreover, the DIFS model reported a deficient soil resupply capacity; this agreed with low R values, which were mostly attributed to the limited available pool of Cu in the soil solid phase.
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assessment of labile zn in reservoir Riparian Soils using dgt difs and sequential extraction
Ecotoxicology and Environmental Safety, 2018Co-Authors: Li Gao, Bo Gao, Wenqi Peng, Ke SunAbstract:Abstract The middle route of the South-to-North Water Diversion project alleviates drought in northern China, especially reducing water shortage pressure in Beijing. However, after submersion, the potential release risk of metals in newly submerged Soils into the water in the receiving reservoir remains unclear. Here, we assess the labile Zn in the Riparian Soils of Miyun Reservoir (MYR) using the diffusive gradients in thin films (DGT), DGT-induced fluxes in Soils (DIFS) model, and Community Bureau of Reference (BCR) sequential extraction. The results showed that the average Zn concentrations at three sampling sites (S2, S3, and S5) exceeded soil background value (74.8 mg/kg), indicative of Zn accumulation in the MYR. The concentrations of DGT-labile Zn varied within 39.7–62.4 μg/L (average: 56.7 μg/L), with the greatest value observed at 145 m at sampling site S3, attributed to anthropogenic activities in recreational areas. The DGT-labile Zn showed no correlation with classes of land, elevations, or soil properties. Sequential extraction results demonstrated that Zn predominantly existed in the residual fraction, but still showed a strong capability for resupply from the solid phase (R >1). The DIFS model simulation results showed that Zn underwent irreversible diffusion of intra-particle metals from the solid phase to the soil solution. Therefore, the potential release risk of labile Zn in Riparian Soils in MYR cannot be ignored, especially for areas experiencing human disturbance.
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pollution characteristics and source identification of trace metals in Riparian Soils of miyun reservoir china
Ecotoxicology and Environmental Safety, 2017Co-Authors: Lanfang Han, Bo Gao, Li Gao, Yang Zhou, Ke SunAbstract:The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline Soils into Miyun Reservoir (MYR). Here, Riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206Pb/207Pb and 208Pb/207Pb values of Soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future.
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predicting remobilization characteristics of cobalt in Riparian Soils in the miyun reservoir prior to water retention
Ecological Indicators, 2017Co-Authors: Li Gao, Bo Gao, Yang Zhou, Ke SunAbstract:Abstract The Middle Route of the South-to-North Water Diversion Project is a significant water diversion project intended to alleviate water shortages in the north China plains, especially for the capital (Beijing). After water retention, the potential ecological risk of metal contamination in the Riparian Soils of the Miyun Reservoir (MYR) to water quality has raised public concern. The remobilization characteristics of cobalt (Co) in MYR Riparian Soils are still unknown. Riparian soil samples (considering five different land use types and three vertical elevations) were collected from the MYR prior to water impoundment. Total Co concentrations, soil properties, total Co in soil solution, Co chemical fractions and labile Co measured by diffusive gradients in thin films (DGT) are applied to investigate the Co remobilization characteristics. The results showed that the total concentrations of Co (C total -Co) were approximately equal to background values of Co in Beijing and China at most of the sites. The highest values of C total -Co were observed at 140 m and 145 m in recreational land (S3), which may be influenced by the anthropogenic activities. No obvious differences in C total -Co and DGT-labile Co (C DGT -Co) were found with the variation of land use types and vertical elevations in the Soils of the MYR. C DGT -Co made up 9%-52% of the total dissolved Co, with an average value of 25%, indicating that Co in the soil solution was partially sustained by the solid phase. The highest C DGT -Co were observed in grassland and mountain land, indicating that the previous intensive mining in the upstream areas of the MYR is responsible for the release of Co. The results of the sequential extraction showed that Co is mainly bound to the residual fraction. DGT-labile Co had no correlation with non-residual fractions measured by sequential extraction, but had a significantly positive relationship with C DGT -Mn, indicating that Co trapped by DGT mainly came from the dissolution of MnO x . When the MYR Riparian Soils are submerged, a reducing environment will be formed. In this case, Co associated with MnO x may be also released into the water.
Bo Gao - One of the best experts on this subject based on the ideXlab platform.
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application of dgt difs and geochemical baseline to assess cd release risk in reservoir Riparian Soils china
Science of The Total Environment, 2019Co-Authors: Bo Gao, Wenqi Peng, Li Gao, Xiaohong WanAbstract:Abstract As the sole drinking water source for Beijing City, Cd has been previously assessed as the major contaminant in Miyun Reservoir (MYR) Riparian Soils. However, the potential release risk of Cd in such Soils, and the labile-Cd release–resupply process from the soil solid phase to solution after water impoundment remain poorly understood. We established a geochemical baseline concentration (GBC) of Cd in MYR Riparian Soils, combined with the diffusive gradient in thin films (DGT) technique and DGT-induced fluxes in soil (DIFS) model, to reveal a dynamic release–resupply process and influencing factors of labile Cd in Riparian Soils. The results showed that Cd GBC in Riparian Soils was 0.12 mg/kg, which was higher than the Cd background value (BV) for Beijing. Using Cd GBC as BV to assess the Cd contaminant level, the geo-accumulation index showed that Cd in Riparian Soils was at the uncontaminated level. In addition, Cd in the Soils belonged to the non-residual fraction using the Community Bureau of Reference method. Cd mobility coefficients (F1/CTotal-Cd) of Soils at low elevation had relatively high values, implying that Cd may be released during the initial impoundment of the MYR. Moreover, correlation analysis was used to found the major influencing factors between DGT-labile Cd and several parameters. The results showed that the DGT-labile Cd was positively correlated to the reducible and oxidizable fraction, CDGT-Fe, and total organic carbon, illustrating that the release of Cd from Soils was controlled by Fe oxides and organic matter. The resupply ability (R values) and DIFS model parameters revealed that Cd in MYR Soils belonged to the partially sustained case, and the slow desorption rate suggested that the release risk of Cd was low in the MYR Riparian Soils.
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assessing cu remobilization in reservoir Riparian Soils prior to water impoundment using dgt and geochemical fractionation
Geoderma, 2018Co-Authors: Haoran Sun, Bo Gao, Li Gao, Ke SunAbstract:Abstract As the world's largest water diversion project, the South-to-North Water Diversion Project in China will have potential environmental effects on the Miyun Reservoir (MYR). However, Cu is a toxic pollutant, and the potential risk of Cu remobilization in MYR Soils after water impoundment remains unknown. Riparian Soils (five land use types and three vertical elevations) were collected from the MYR before water impoundment. Soil properties, total concentrations of Cu in Soils (Ctotal-Cu) and pore water (Csol-Cu), and chemical fractions were measured. Diffusive gradients in thin films (DGT) and the DGT-induced fluxes in Soils (DIFS) model were applied to investigate Cu availability. The average Ctotal-Cu was higher than the Chinese background values, indicating potential anthropogenic input of Cu. No significant influences of land use types/vertical elevations on DGT-labile Cu (CDGT-Cu) and Ctotal-Cu were observed. A significant positive relationship between CDGT-Cu and Csol-Cu showed that CDGT-Cu can effectively predict bioavailable Cu fraction in MYR Soils, whereas CDGT-Cu had no correlation with different chemical fractions measured by European Community Bureau of Reference (BCR) geochemical fractionation, suggesting that BCR chemical fractions cannot reflect Cu mobility in MYR Soils. Risk assessment code showed a low risk of Cu remobilization in MYR Soils, but a reducing environment would cause higher mobilization of Cu associated with Fe/Mn oxides after water impoundment. Moreover, the DIFS model reported a deficient soil resupply capacity; this agreed with low R values, which were mostly attributed to the limited available pool of Cu in the soil solid phase.
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assessment of labile zn in reservoir Riparian Soils using dgt difs and sequential extraction
Ecotoxicology and Environmental Safety, 2018Co-Authors: Li Gao, Bo Gao, Wenqi Peng, Ke SunAbstract:Abstract The middle route of the South-to-North Water Diversion project alleviates drought in northern China, especially reducing water shortage pressure in Beijing. However, after submersion, the potential release risk of metals in newly submerged Soils into the water in the receiving reservoir remains unclear. Here, we assess the labile Zn in the Riparian Soils of Miyun Reservoir (MYR) using the diffusive gradients in thin films (DGT), DGT-induced fluxes in Soils (DIFS) model, and Community Bureau of Reference (BCR) sequential extraction. The results showed that the average Zn concentrations at three sampling sites (S2, S3, and S5) exceeded soil background value (74.8 mg/kg), indicative of Zn accumulation in the MYR. The concentrations of DGT-labile Zn varied within 39.7–62.4 μg/L (average: 56.7 μg/L), with the greatest value observed at 145 m at sampling site S3, attributed to anthropogenic activities in recreational areas. The DGT-labile Zn showed no correlation with classes of land, elevations, or soil properties. Sequential extraction results demonstrated that Zn predominantly existed in the residual fraction, but still showed a strong capability for resupply from the solid phase (R >1). The DIFS model simulation results showed that Zn underwent irreversible diffusion of intra-particle metals from the solid phase to the soil solution. Therefore, the potential release risk of labile Zn in Riparian Soils in MYR cannot be ignored, especially for areas experiencing human disturbance.
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predicting ni dynamic mobilization in reservoir Riparian Soils prior to water submergence using dgt and difs
Chemosphere, 2018Co-Authors: Li Gao, Bo Gao, Shuhua Yin, Jijun GaoAbstract:Abstract The South-to-North Water Diversion Project has been initiated to address the problem of water shortages in north China. However, the environmental impact of this project is currently unclear, especially for the geochemical process of toxic trace metals in reservoir Riparian soil following water submergence. The mobility of Ni in Miyun Reservoir Riparian soil samples was investigated using diffusive gradients in thin films (DGT), considering five different land use types and three vertical elevations. The DGT-induced fluxes in soil (DIFS) model was applied to simulate the kinetics of Ni mobilization in the soil. The results showed that the average concentration of Ni was 36.58 mg/kg, which was slightly higher than the corresponding background values reported for both Beijing and China. Coincidentally, the highest concentrations of both total Ni and DGT-labile Ni (CDGT-Ni) were observed at the same site (recreational area), indicating that anthropogenic activities may have contributed to the release of Ni. Land use type and vertical elevation had no significant influence on CDGT-Ni. In addition, CDGT-Ni was positively correlated with reducible fraction, CDGT-Fe, CDGT-Mn, and TOC, indicating that Ni in the Soils was adsorbed mainly on the Fe/Mn oxides and organic matter. Moreover, the low values of R (CDGT-Ni/Csol-Ni, R
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pollution characteristics and source identification of trace metals in Riparian Soils of miyun reservoir china
Ecotoxicology and Environmental Safety, 2017Co-Authors: Lanfang Han, Bo Gao, Li Gao, Yang Zhou, Ke SunAbstract:The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline Soils into Miyun Reservoir (MYR). Here, Riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution. The potential ecological risk assessment revealed considerable contamination of recreational land, with Cd being the predominant contaminant. Chemical fractionations showed that Cu, arsenic (As), Pb and Cd had potential release risks. Additionally, the 206Pb/207Pb and 208Pb/207Pb values of Soils were similar to those of coal combustion. By combining principal component analysis (PCA) with Pb isotopic results, coal combustion was identified as the major anthropogenic source of Zn, Cr, Cu, Cd and Pb. Moreover, isotope ratios of Pb fell in the scope of aerosols, indicating that atmospheric deposition may be the primary input pathway of anthropogenic Zn, Cr, Cu, Cd and Pb. Therefore, controlling coal combustion should be a priority to reduce effectively the introduction of additional Zn, Cu, Cd, and Pb to the area in the future.
Stephan Kohler - One of the best experts on this subject based on the ideXlab platform.
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from soil water to surface water how the Riparian zone controls element transport from a boreal forest to a stream
Biogeosciences, 2017Co-Authors: Fredrik Lidman, Hjalmar Laudon, Asa Boily, Stephan KohlerAbstract:Abstract. Boreal headwaters are often lined by strips of highly organic Soils, which are the last terrestrial environment to leave an imprint on discharging groundwater before it enters a stream. Because these Riparian Soils are so different from the Podzol Soils that dominate much of the boreal landscape, they are known to have a major impact on the biogeochemistry of important elements such as C, N, P and Fe and the transfer of these elements from terrestrial to aquatic ecosystems. For most elements, however, the role of the Riparian zone has remained unclear, although it should be expected that the mobility of many elements is affected by changes in, for example, pH, redox potential and concentration of organic carbon as they are transported through the Riparian zone. Therefore, soil water and groundwater was sampled at different depths along a 22 m hillslope transect in the Krycklan catchment in northern Sweden using soil lysimeters and analysed for a large number of major and trace elements (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Si, Sr, Th, Ti, U, V, Zn, Zr) and other parameters such as sulfate and total organic carbon (TOC). The results showed that the concentrations of most investigated elements increased substantially (up to 60 times) as the water flowed from the uphill mineral Soils and into the Riparian zone, largely as a result of higher TOC concentrations. The stream water concentrations of these elements were typically somewhat lower than in the Riparian zone, but still considerably higher than in the uphill mineral Soils, which suggests that Riparian Soils have a decisive impact on the water quality of boreal streams. The degree of enrichment in the Riparian zone for different elements could be linked to the affinity for organic matter, indicating that the pattern with strongly elevated concentrations in Riparian Soils is typical for organophilic substances. One likely explanation is that the solubility of many organophilic elements increases as a result of the higher concentrations of TOC in the Riparian zone. Elements with low or modest affinity for organic matter (e.g. Na, Cl, K, Mg and Ca) occurred in similar or lower concentrations in the Riparian zone. Despite the elevated concentrations of many elements in Riparian soil water and groundwater, no increase in the concentrations in biota could be observed (bilberry leaves and spruce shoots).
D A Barry - One of the best experts on this subject based on the ideXlab platform.
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analysis of carbon and nitrogen dynamics in Riparian Soils model development
Science of The Total Environment, 2012Co-Authors: Alessandro Brovelli, Jordi Batlleaguilar, D A BarryAbstract:The quality of Riparian Soils and their ability to buffer contaminant releases to aquifers and streams are connected intimately to moisture content and nutrient dynamics, in particular of carbon (C) and nitrogen (N). A multi-compartment model – named the Riparian Soil Model (RSM) – was developed to help investigate the influence and importance of environmental parameters, climatic factors and management practices on soil ecosystem functioning in Riparian areas. The model includes numerous improvements compared to many similar tools, in particular regarding the capability to simulate a wide range of temporal scales, from daily to centuries, along with the ability to predict the concentration and vertical distribution of dissolved organic matter (DOM). The ecological importance of DOM has been highlighted on numerous occasions, and it was found that its concentration controls the amount of soil organic matter (SOM) stored in the soil as well as the respiration rate. The moisture content was computed using a detailed water budget approach, assuming that within each time step all the water above field capacity drains to the layer underneath, until it becomes fully saturated. A mass balance approach was also used for nutrient transport, whereas the biogeochemical reaction network was developed as an extension of an existing C and N turnover model. Temperature changes across the soil profile were simulated using an existing analytical solution of the heat transport equation, assuming periodic temperature changes in the topsoil. To verify the consistency of model predictions and illustrate its capabilities, a synthetic but realistic soil profile in a deciduous forest was simulated. Model parameters were taken from the literature, and model predictions were consistent with experimental observations for a similar scenario. Modelling results stressed the importance of environmental conditions on SOM cycling in Soils. The mineral and organic C and N stocks fluctuate at different time scales in response to oscillations in climatic conditions and vegetation inputs/uptake. Low frequency fluctuations with a period larger than 10 y were observed also, which were not connected to any single environmental process.
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analysis of carbon and nitrogen dynamics in Riparian Soils model validation and sensitivity to environmental controls
Science of The Total Environment, 2012Co-Authors: Jordi Batlleaguilar, Alessandro Brovelli, Joerg Luster, Juna Shrestha, Pascal A Niklaus, D A BarryAbstract:The Riparian Soil Model (RSM) of Brovelli et al. (2012) was applied to study soil nutrient turnover in a revitalized section of the Thur River, North-East Switzerland. In the present work, the model was calibrated on field experimental data, and satisfactorily reproduced soil respiration, organic matter stocks and inorganic nitrogen fluxes. Calibrated rates were in good agreement with the ranges reported in the literature. The main discrepancies between model and observations were for dissolved organic carbon. The sensitivity of the model to environmental factors was also analyzed. Soil temperature was the most influential factor at daily and seasonal scales while effects of soil moisture were weak overall. The ecosystem sensitivity to temperature changes was quantified using the Q10 index. The seasonal behavior observed was related to the influence of other forcing factors and to the different state (density and activity) of the microbial biomass pool during the year. Environmental factors influencing microbial decomposition, such as the C:N ratio and litter input rate, showed intermediate sensitivity. Since these parameters are tightly linked to the vegetation type, the analysis highlighted the effect of the aboveground ecosystem on soil functioning.
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modelling of biogeochemical transformations in Riparian Soils lessons learned from the thur river revitalization experiment and open questions
River corridor restoration conference 2011, 2011Co-Authors: Alessandro Brovelli, Jordi Battleaguilar, D A BarryAbstract:In recent years, the key environmental importance of natural, healthy Riparian ecosystems and Soils has been recognized and restoration of degraded lands towards their former natural state has become an area of active research worldwide. Land use changes and restoration practices are known to affect both soil nutrient dynamics as well as nutrient transport to neighbouring areas. Microbiological transformations of the soil organic matter, including decomposition and nutrient turnover, are controlled to a large extent by soil water content, which is in turn influenced by climatic and environmental conditions such as precipitation and evapo-transpiration. In this context a novel mechanistic model to simulate water flow in the unsaturated zone, the dynamics of the soil microbial populations, carbon and nitrogen transport and turnover was developed. The mathematical model was based on a number of simplifying assumptions that will be discussed in detail in order to highlight its strengths and weaknesses and to identify the soil processes that require further research and understanding. The model was applied to analyse nutrient cycling and buffering capacity of the RECORD field site (Thur river, Thurgau canton, Switzerland), a Riparian area undergoing restoration. Comparison of experimental data and simulation results in order to calibrate and validate the model is a difficult but crucial – and often overlooked – task. The strategies that were devised and applied to this case study will be presented. Based on the experience gained some ideas to facilitate such comparisons in the future will be presented. The dynamics of carbon and nitrogen at different time scales was analysed, as well as the effect of changing environmental conditions. These include the occurrence and amount of precipitation, the type of vegetation and river dynamics. Based on modelling results we concluded that soil organic matter and nutrient pools fluctuate in response to environmental forcing factors over a range time scales, from one day to one century. In other words, soil composition and functioning do not always respond rapidly to changes in external factors, a crucial aspect that should always be considered while designing river revitalization projects.
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analysis of carbon and nitrogen turnover in Riparian Soils undergoing restoration
AGU Fall Meeting Abstracts, 2010Co-Authors: Alessandro Brovelli, Jordi Batlleaguilar, D A Barry, Joerg Luster, Juna Shrestha, Pascal A NiklausAbstract:Keywords: Nutrient dynamics ; Riparian zone ; Ecosystem functioning Note: Abstract B14A-05 Reference EPFL-TALK-162515 Record created on 2011-01-24, modified on 2016-08-09
