| 1. |
- Berggren, Martin, et al.
(författare)
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Unified understanding of intrinsic and extrinsic controls of dissolved organic carbon reactivity in aquatic ecosystems
- 2022
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 103:9
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Tidskriftsartikel (refereegranskat)abstract
- Despite our growing understanding of the global carbon cycle, scientific consensus on the drivers and mechanisms that control dissolved organic carbon (DOC) turnover in aquatic systems is lacking, hampered by the mismatch between research that approaches DOC reactivity from either intrinsic (inherent chemical properties) or extrinsic (environmental context) perspectives. Here we propose a conceptual view of DOC reactivity in which the combination of intrinsic and extrinsic factors controls turnover rates and determines which reactions will occur. We review three major types of reactions (biological, photochemical, and flocculation) from an intrinsic chemical perspective and further define the environmental features that modulate the expression of chemically inherent reactivity potential. Finally, we propose hypotheses of how extrinsic and intrinsic factors together shape patterns in DOC turnover across the land-to-ocean continuum, underscoring that there is no intrinsic DOC reactivity without environmental context. By acknowledging the intrinsic–extrinsic control duality, our framework intends to foster improved modeling of DOC reactivity and its impact on ecosystem services.
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| 2. |
- Bieroza, Magdalena, et al.
(författare)
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Advances in Catchment Science, Hydrochemistry, and Aquatic Ecology Enabled by High-Frequency Water Quality Measurements
- 2023
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 57, s. 4701-4719
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Forskningsöversikt (refereegranskat)abstract
- High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.
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| 3. |
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| 4. |
- Bieroza, Magdalena
(författare)
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Fingerprinting hydrological and biogeochemical drivers of freshwater quality
- 2020
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 35
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the interplay between hydrological flushing and biogeochemical cycling in streams is now possible owing to advances in high-frequency water quality measurements with in situ sensors. It is often assumed that storm events are periods when biogeochemical processes become suppressed and longitudinal transport of solutes and particulates dominates. However, high-frequency data show that diel cycles are a common feature of water quality time series and can be preserved during storm events, especially those of low-magnitude. In this study, we mine a high-frequency dataset and use two key hydrochemical indices, hysteresis and flushing index to evaluate the diversity of concentration-discharge relationships in third order agricultural stream. We show that mobilization patterns, inferred from the hysteresis index, change on a seasonal basis, with a predominance of rapid mobilization from surface and near stream sources during winter high-magnitude storm events and of delayed mobilization from subsurface sources during summer low-magnitude storm events. Using dynamic harmonic regression, we were able to separate concentration signals during storm events into hydrological flushing (using trend as a proxy) and biogeochemical cycling (using amplitude of a diel cycle as a proxy). We identified three groups of water quality parameters depending on their typical c-q response: flushing dominated parameters (phosphorus and sediments), mixed flushing and cycling parameters (nitrate nitrogen, specific conductivity and pH) and cycling dominated parameters (dissolved oxygen, redox potential and water temperature). Our results show that despite large storm to storm diversity in hydrochemical responses, storm event magnitude and timing have a critical role in controlling the type of mobilization, flushing and cycling behaviour of each water quality constituent. Hydrochemical indices can be used to fingerprint the effect of hydrological disturbance on freshwater quality and can be useful in determining the impacts of global change on stream ecology.
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| 5. |
- Bieroza, Magdalena, et al.
(författare)
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Hydrologic Extremes and Legacy Sources Can Override Efforts to Mitigate Nutrient and Sediment Losses at the Catchment Scale
- 2019
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Ingår i: Journal of Environmental Quality. - : AMER SOC AGRONOMY. - 0047-2425 .- 1537-2537. ; 48:5, s. 1314-1324
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Tidskriftsartikel (refereegranskat)abstract
- Combating eutrophication requires changes in land and water management in agricultural catchments and implementation of mitigation measures to reduce phosphorus (P), nitrogen (N) and suspended sediment (SS) losses. To date, such mitigation measures have been built in many agricultural catchments, but there is a lack of studies evaluating their effectiveness. Here we evaluated the effectiveness of mitigation measures in a clay soildominated headwater catchment by combining the evaluation of long-term and high-frequency data with punctual measurements upstream and downstream of three mitigation measures: limefilter drains, a two-stage ditch, and a sedimentation pond. Long-term hydrochemical data at the catchment outlet showed a significant decrease in P (-15%) and SS (-28%) and an increase in nitrate nitrogen (NO3-N, + 13%) concentrations. Highfrequency (hourly) measurements with a wet-chemistry analyzer (total and reactive P) and optical sensor (NO3-N and SS) showed that the catchment is an abundant source of nutrients and sediments and that their transport is exacerbated by prolonged drought and resuspension of stream sediments during storm events. Lime-filter drains showed a decrease in SS by 76% and total P by 80% and an increase in NO3-N by 45% compared with traditional drains, potentially indicating pollution swapping. The effectiveness of two-stage ditch and sedimentation pond was less evident and depended on the prevalent hydrometeorological conditions that drove the resuspension of bed sediments and associated sediment-bound P transport. These results suggest that increased frequency of prolonged drought due to changing weather patterns and resuspension of SS and sediment-bound P during storm events can override the generally positive effect of mitigation measures.
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| 6. |
- Bieroza, Magdalena
(författare)
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Hydrological and Chemical Controls on Nutrient and Contaminant Loss to Water in Agricultural Landscapes
- 2020
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient and contaminant losses in agricultural landscapes are directly controlled by hydrological (flow pathways), chemical (sorption, speciation and transformations), biological processes (fixation, uptake) and indirectly by demographic (growing population), economic (food production) and societal drivers (individual attitudes, farming tradition) that control how agricultural landscapes are managed [...]
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| 7. |
- Bieroza, Magdalena
(författare)
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Mixing of arsenic-rich groundwater and surface water in drinking water distribution systems: Implications for contaminants, disinfection byproducts and organic components
- 2022
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 292
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Tidskriftsartikel (refereegranskat)abstract
- The utilization of groundwaters containing high levels of arsenic (As) for drinking water purposes presents major health and economic challenges for water utilities. One low-cost approach is to mix arsenic-rich groundwater (GW) with arsenic-free surface waters (SW) to achieve acceptable As levels. In this study we investigated the effect of different mixing ratios on water quality in an eastern Croatian water distribution system (WDS). To investigate the effects of mixing on drinking water quality, we measured the organic matter (OM) composition, disinfection byproduct (DBP) and metal concentrations in differently mixed ratios of GW and SW within the WDS. Fluorescence analysis revealed that the GW and SW had similar OM composition, with an almost equal ratio of humic- and protein-like OM throughout the WDS despite fluorescence indices revealing slightly different OM sources between the two water types. The tyrosine-like OM component was more variable, increasing during warmer months and towards the end of the WDS, most likely due to enhanced biofilm formation. Arsenic concentrations decreased to below 10 μg/L in the second half of the sampling campaign. Acceptable water quality was achieved after a period of destabilization and solubilization of loose deposits within the WDS resulting in their mobilization caused by water quality changes. Principal component and classification analysis, regression models and Spearman correlation coefficients revealed an association between As, OM and DBP concentrations with these correlations suggestive of their role in As mobilization in the WDS. Changing source waters, with different OM content and characteristics, corresponded to variable As release within the WDS.
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| 8. |
- Bieroza, Magdalena, et al.
(författare)
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Recognizing Agricultural Headwaters as Critical Ecosystems
- 2024
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Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 58, s. 4852-4858
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural headwaters are positioned at the interface between terrestrial and aquatic ecosystems and, therefore, at the margins of scientific disciplines. They are deemed devoid of biodiversity and too polluted by ecologists, overlooked by hydrologists, and are perceived as a nuisance by landowners and water authorities. While agricultural streams are widespread and represent a major habitat in terms of stream length, they remain understudied and thereby undervalued. Agricultural headwater streams are significantly modified and polluted but at the same time are the critical linkages among land, air, and water ecosystems. They exhibit the largest variation in streamflow, water quality, and greenhouse gas emission with cascading effects on the entire stream networks, yet they are underrepresented in monitoring, remediation, and restoration. Therefore, we call for more intense efforts to characterize and understand the inherent variability and sensitivity of these ecosystems to global change drivers through scientific and regulatory monitoring and to improve their ecosystem conditions and functions through purposeful and evidence-based remediation.
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| 9. |
- Bieroza, Magdalena
(författare)
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Storm size and hydrologic modification influence nitrate mobilization and transport in agricultural watersheds
- 2021
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Ingår i: Biogeochemistry. - : Springer Science and Business Media LLC. - 0168-2563 .- 1573-515X. ; 156, s. 319-334
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Tidskriftsartikel (refereegranskat)abstract
- Agriculturally-driven land use change and hydrologic modifications have influenced solute transport in midwestern U.S. streams. A clear understanding of the mechanisms driving nutrient export from agricultural watersheds will be critical in mitigating diffuse nutrient pollution, given anticipated shifts in hydrology associated with a changing climate. Specifically, more frequent, intense precipitation and altered snow patterns are predicted for the upper Midwest. We used four years of high-frequency nitrate (NO3--N) sensor data from two tile-drained, agricultural watersheds in Indiana to explore NO3--N export for 200 storms. We used concentration-discharge (C-Q) relationships and two indices, the hysteresis index (HI) and flushing index (FI), to understand physicochemical controls of NO3--N export across time scales. On both annual and seasonal time scales, we found NO3--N concentrations were largely chemostatic; however, patterns in FI suggested C-Q relationships for individual storms were highly variable, which may influence estimates of watershed-scale NO3--N export. We also found storm NO3--N export was strongly driven by mobilization of distal sources, given the predominance of counterclockwise hysteresis. In both watersheds, HI and FI values varied seasonally and with storm size, and patterns were linked to changes in hydrologic connectivity related to variation in seasonal tile drain flow. Variation in storm-specific NO3--N yields was driven by event runoff, storm duration, and antecedent basin moisture, rather than antecedent precipitation. Overall, we found that high-frequency NO3--N data accurately documented the magnitude of the ecological challenge presented by storm-driven nutrient export in agricultural watersheds.
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| 10. |
- Bieroza, Magdalena, et al.
(författare)
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The Cold Region Critical Zone in Transition: Responses to Climate Warming and Land Use Change
- 2021
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Ingår i: Annual Review of Environment and Resources. - : Annual Reviews. - 1543-5938 .- 1545-2050. ; 46, s. 111-134
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Forskningsöversikt (refereegranskat)abstract
- Global climate warming disproportionately affects high-latitude and mountainous terrestrial ecosystems. Warming is accompanied by permafrost thaw, shorter winters, earlier snowmelt, more intense soil freeze-thaw cycles, drier summers, and longer fire seasons. These environmental changes in turn impact surface water and groundwater flow regimes, water quality, greenhouse gas emissions, soil stability, vegetation cover, and soil (micro)biological communities. Warming also facilitates agricultural expansion, urban growth, and natural resource development, adding growing anthropogenic pressures to cold regions' landscapes, soil health, and biodiversity. Further advances in the predictive understanding of how cold regions' critical zone processes, functions, and ecosystem services will continue to respond to climate warming and land use changes require multiscale monitoring technologies coupled with integrated observational and modeling tools. We highlight some of the major challenges, knowledge gaps, and opportunities in cold region critical zone research, with an emphasis on subsurface processes and responses in both natural and agricultural ecosystems.
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