The Experts below are selected from a list of 51300 Experts worldwide ranked by ideXlab platform
Anna Fedders - One of the best experts on this subject based on the ideXlab platform.
-
Biogeochemical regime shifts in coastal landscapes: the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low (27 °C and SO4 2− was
-
biogeochemical regime shifts in coastal landscapes the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low ( 10 mg L−1), regardless of whether the SO4 2− source was agriculture or saltwater. Elevated CH4 (as high as 1,500 µg L−1 and 45 mg m−2 h−1) was only observed on dates when air temperatures were >27 °C and SO4 2− was <10 mg L−1. Despite elevated ammonium (NH4 +) for saltwater exposed sites, concentrations of N2O remained low (<5 µg L−1 and <10 µg m−2 h−1), except when fertilizer derived nitrate (NO3 −) concentrations were high and N2O increased as high as 156 µg L−1. Our results suggest that although both saltwater and agriculture derived SO4 2− may suppress CH4, increases in N2O associated with fertilizer derived NO3 − may offset that reduction in wetlands exposed to both Agricultural runoff and saltwater incursion.
Ashley M. Helton - One of the best experts on this subject based on the ideXlab platform.
-
Biogeochemical regime shifts in coastal landscapes: the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low (27 °C and SO4 2− was
-
biogeochemical regime shifts in coastal landscapes the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low ( 10 mg L−1), regardless of whether the SO4 2− source was agriculture or saltwater. Elevated CH4 (as high as 1,500 µg L−1 and 45 mg m−2 h−1) was only observed on dates when air temperatures were >27 °C and SO4 2− was <10 mg L−1. Despite elevated ammonium (NH4 +) for saltwater exposed sites, concentrations of N2O remained low (<5 µg L−1 and <10 µg m−2 h−1), except when fertilizer derived nitrate (NO3 −) concentrations were high and N2O increased as high as 156 µg L−1. Our results suggest that although both saltwater and agriculture derived SO4 2− may suppress CH4, increases in N2O associated with fertilizer derived NO3 − may offset that reduction in wetlands exposed to both Agricultural runoff and saltwater incursion.
Emily S. Bernhardt - One of the best experts on this subject based on the ideXlab platform.
-
Biogeochemical regime shifts in coastal landscapes: the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low (27 °C and SO4 2− was
-
biogeochemical regime shifts in coastal landscapes the contrasting effects of saltwater incursion and Agricultural Pollution on greenhouse gas emissions from a freshwater wetland
Biogeochemistry, 2014Co-Authors: Ashley M. Helton, Emily S. Bernhardt, Anna FeddersAbstract:Many coastal plain wetlands receive nutrient Pollution from Agricultural fields and are particularly vulnerable to saltwater incursion. Although wetlands are a major source of the greenhouse gases methane (CH4) and nitrous oxide (N2O), the consequences of salinization for greenhouse gas emissions from wetlands with high Agricultural Pollution loads is rarely considered. Here, we asked how saltwater exposure alters greenhouse gas emissions from a restored freshwater wetland that receives nutrient loading from upstream farms. During March to November 2012, we measured greenhouse gases along a ~2 km inundated portion of the wetland. Sampling locations spanned a wide chemical gradient from sites receiving seasonal fertilizer nitrogen and sulfate (SO4 2−) loads to sites receiving seasonal increases in marine salts. Concentrations and fluxes of CH4 were low ( 10 mg L−1), regardless of whether the SO4 2− source was agriculture or saltwater. Elevated CH4 (as high as 1,500 µg L−1 and 45 mg m−2 h−1) was only observed on dates when air temperatures were >27 °C and SO4 2− was <10 mg L−1. Despite elevated ammonium (NH4 +) for saltwater exposed sites, concentrations of N2O remained low (<5 µg L−1 and <10 µg m−2 h−1), except when fertilizer derived nitrate (NO3 −) concentrations were high and N2O increased as high as 156 µg L−1. Our results suggest that although both saltwater and agriculture derived SO4 2− may suppress CH4, increases in N2O associated with fertilizer derived NO3 − may offset that reduction in wetlands exposed to both Agricultural runoff and saltwater incursion.
Kuno Kasak - One of the best experts on this subject based on the ideXlab platform.
-
Treatment Efficiency of Diffuse Agricultural Pollution in a Constructed Wetland Impacted by Groundwater Seepage
Water, 2018Co-Authors: Keit Kill, Jaan Pärn, Ülo Mander, Rauno Lust, Kuno KasakAbstract:Diffuse Agricultural Pollution degrades water quality and is one of the main causes of eutrophication; therefore, it is important to reduce it. Constructed wetlands (CW) can be used as an effective measure for water quality improvement. There are two possible ways to establish surface flow CWs, in-stream and off-stream. We studied treatment efficiency of the in-stream free surface flow (FSW) Vända CW in southern Estonia from March 2017 until July 2018. The CW consists of two shallow-water parts planted with cattail (Typha latifolia). According to our analyses, the CW reduced total phosphorus (TP) and phosphate (PO4-P) by 20.5% and 16.3%, respectively, however, in summer, phosphorus removal was twice as high. We saw significant logarithmic correlation between flow rates and log TP and log PO4-P removal efficiency (rs = 0.53, rs = 0.63, p < 0.01 respectively). Yearly reduction of total organic carbon was 12.4% while total inorganic carbon increased by 9.7% due to groundwater seepage. Groundwater inflow also increased the concentration of total nitrogen in the outlet by 27.7% and nitrate concentration by 31.6%. In-stream FWS CWs are a promising measure to reduce diffuse Pollution from agriculture; however, our experience and literature data prove that there are several factors that can influence CWs’ treatment efficiency.
-
Efficiency of a newly established in-stream constructed wetland treating diffuse Agricultural Pollution
Ecological Engineering, 2018Co-Authors: Kuno Kasak, Keit Kill, Jaan Pärn, Ülo ManderAbstract:Abstract Diffuse Agricultural Pollution, especially from intensively managed Agricultural land is a major cause of eutrophication, therefore it is important to reduce the diffuse load to surface water. Constructed wetlands (CW) are an effective measure for improving water quality and reducing nutrient runoff from agriculture by using natural water treatment mechanisms. We studied treatment efficiency of an in-stream free surface flow (FSW) Vanda CW in southern Estonia from 16th of March 2017 till 11th of January 2018. Vanda CW has a catchment area of 2.2 km2 and of which approximately 62% is under intensive Agricultural management. The CW consists of a sedimentation pond followed by two shallow water wetlands planted with cattail (Typha latifolia). Our analyses showed that the CW retained 17.5 kg phosphorus (P) ha−1 yr−1. During the warm period phosphate removal was up to 41.8% whereas annually it was only 14.4%. Phosphate removal efficiency showed strong negative correlation (R2 = 0.58, p
Ülo Mander - One of the best experts on this subject based on the ideXlab platform.
-
Treatment Efficiency of Diffuse Agricultural Pollution in a Constructed Wetland Impacted by Groundwater Seepage
Water, 2018Co-Authors: Keit Kill, Jaan Pärn, Ülo Mander, Rauno Lust, Kuno KasakAbstract:Diffuse Agricultural Pollution degrades water quality and is one of the main causes of eutrophication; therefore, it is important to reduce it. Constructed wetlands (CW) can be used as an effective measure for water quality improvement. There are two possible ways to establish surface flow CWs, in-stream and off-stream. We studied treatment efficiency of the in-stream free surface flow (FSW) Vända CW in southern Estonia from March 2017 until July 2018. The CW consists of two shallow-water parts planted with cattail (Typha latifolia). According to our analyses, the CW reduced total phosphorus (TP) and phosphate (PO4-P) by 20.5% and 16.3%, respectively, however, in summer, phosphorus removal was twice as high. We saw significant logarithmic correlation between flow rates and log TP and log PO4-P removal efficiency (rs = 0.53, rs = 0.63, p < 0.01 respectively). Yearly reduction of total organic carbon was 12.4% while total inorganic carbon increased by 9.7% due to groundwater seepage. Groundwater inflow also increased the concentration of total nitrogen in the outlet by 27.7% and nitrate concentration by 31.6%. In-stream FWS CWs are a promising measure to reduce diffuse Pollution from agriculture; however, our experience and literature data prove that there are several factors that can influence CWs’ treatment efficiency.
-
Efficiency of a newly established in-stream constructed wetland treating diffuse Agricultural Pollution
Ecological Engineering, 2018Co-Authors: Kuno Kasak, Keit Kill, Jaan Pärn, Ülo ManderAbstract:Abstract Diffuse Agricultural Pollution, especially from intensively managed Agricultural land is a major cause of eutrophication, therefore it is important to reduce the diffuse load to surface water. Constructed wetlands (CW) are an effective measure for improving water quality and reducing nutrient runoff from agriculture by using natural water treatment mechanisms. We studied treatment efficiency of an in-stream free surface flow (FSW) Vanda CW in southern Estonia from 16th of March 2017 till 11th of January 2018. Vanda CW has a catchment area of 2.2 km2 and of which approximately 62% is under intensive Agricultural management. The CW consists of a sedimentation pond followed by two shallow water wetlands planted with cattail (Typha latifolia). Our analyses showed that the CW retained 17.5 kg phosphorus (P) ha−1 yr−1. During the warm period phosphate removal was up to 41.8% whereas annually it was only 14.4%. Phosphate removal efficiency showed strong negative correlation (R2 = 0.58, p
