Pub Date : 2023-07-11DOI: 10.3389/frwa.2023.1057725
Rachel Kaitlyn Uecker, B. Flinchum, W. Holbrook, B. Carr
Physical, chemical, and biological processes create and maintain the critical zone (CZ). In weathered and crystalline rocks, these processes occur over 10–100 s of meters and transform bedrock into soil. The CZ provides pore space and flow paths for groundwater, supplies nutrients for ecosystems, and provides the foundation for life. Vegetation in the aboveground CZ depends on these components and actively mediates Earth system processes like evapotranspiration, nutrient and water cycling, and hill slope erosion. Therefore, the vertical and lateral extent of the CZ can provide insight into the important chemical and physical processes that link life on the surface with geology 10–100 s meters below. In this study, we present 3.9 km of seismic refraction data in a weathered and crystalline granite in the Laramie Range, Wyoming. The refraction data were collected to investigate two ridges with clear contrasts in vegetation and slope. Given the large contrasts in slope, aspect, and vegetation cover, we expected large differences in CZ structure. However, our results suggest no significant differences in large-scale (>10 s of m) CZ structure as a function of slope or aspect. Our data appears to suggest a relationship between LiDAR-derived canopy height and depth to fractured bedrock where the tallest trees are located over regions with the shallowest depth to fractured bedrock. After separating our data by the presence or lack of vegetation, higher P-wave velocities under vegetation is likely a result of higher saturation.
物理、化学和生物过程创造并维持临界区。在风化和结晶岩石中，这些过程发生在10-100米深的地方，把基岩变成土壤。CZ为地下水提供孔隙空间和流动路径，为生态系统提供养分，为生命提供基础。地上CZ的植被依赖于这些成分，并积极调节蒸散发、养分和水循环、坡面侵蚀等地球系统过程。因此，CZ的垂直和横向范围可以深入了解将地表生命与地下10-100米的地质联系起来的重要化学和物理过程。在这项研究中，我们展示了怀俄明州拉勒米山脉风化和结晶花岗岩中3.9公里的地震折射数据。利用折射率数据对植被和坡度对比明显的两个山脊进行了研究。考虑到坡度、坡向和植被覆盖的巨大差异，我们预计CZ结构会有很大差异。然而，我们的研究结果表明，大尺度(bbb10s m) CZ结构在坡度或坡向上没有显著差异。我们的数据似乎表明，激光雷达得出的冠层高度与裂缝基岩深度之间存在关系，其中最高的树木位于裂缝基岩深度最浅的区域。根据有无植被对数据进行分离后，植被下较高的纵波速度可能是较高饱和度的结果。
{"title":"Mapping bedrock topography: a seismic refraction survey and landscape analysis in the Laramie Range, Wyoming","authors":"Rachel Kaitlyn Uecker, B. Flinchum, W. Holbrook, B. Carr","doi":"10.3389/frwa.2023.1057725","DOIUrl":"https://doi.org/10.3389/frwa.2023.1057725","url":null,"abstract":"Physical, chemical, and biological processes create and maintain the critical zone (CZ). In weathered and crystalline rocks, these processes occur over 10–100 s of meters and transform bedrock into soil. The CZ provides pore space and flow paths for groundwater, supplies nutrients for ecosystems, and provides the foundation for life. Vegetation in the aboveground CZ depends on these components and actively mediates Earth system processes like evapotranspiration, nutrient and water cycling, and hill slope erosion. Therefore, the vertical and lateral extent of the CZ can provide insight into the important chemical and physical processes that link life on the surface with geology 10–100 s meters below. In this study, we present 3.9 km of seismic refraction data in a weathered and crystalline granite in the Laramie Range, Wyoming. The refraction data were collected to investigate two ridges with clear contrasts in vegetation and slope. Given the large contrasts in slope, aspect, and vegetation cover, we expected large differences in CZ structure. However, our results suggest no significant differences in large-scale (>10 s of m) CZ structure as a function of slope or aspect. Our data appears to suggest a relationship between LiDAR-derived canopy height and depth to fractured bedrock where the tallest trees are located over regions with the shallowest depth to fractured bedrock. After separating our data by the presence or lack of vegetation, higher P-wave velocities under vegetation is likely a result of higher saturation.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":"1 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69816811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-06DOI: 10.3389/frwa.2023.1043628
Raktima Ghosh, Jenia Mukherjee, Aishik Bandyopadhyay, S. Chatterjee, Anuradha Choudry, Poulami Ghosh, Souradip Pathak, Amrita Sen, Priyadarsini Sinha
The south-western fringe of the Indian Sundarbans hosts a number of fish drying collectives that are exposed to a bundle of mutually reinforcing social-ecological-institutional risks. Despite its wide contribution to local-regional food security and livelihoods, dried fish production has received little attention in research and policy circles so far. As part of the Social Sciences and Humanities Research Council (SSHRC) sponsored Dried Fish Matters global partnership project, our research team seeks to address this lack in two ways: (i) delineating knowledge base through a systematic literature review on intersecting social-ecological and sociohydrological dimensions of integrated fisheries and fish drying practices, and (ii) employing a knowledge co-production approach that involves participation of dry-fishers, researchers, fishworkers' forum (partner organization), and scientists for meaningful understandings about the constraints and potentials in the sector. In this essay, we applied a three-step methodology to arrive at a crisscrossing conceptual, empirical, and collective understandings on the 'invisible' dried fish value chain in the Indian Sundarbans. With detailed lessons from the field, our interdisciplinary research team acts as a liaison among the groups to build a collaborative space for interactions, recognize prevalent adaptive practices and identify pathways toward short-, intermediate-, and long-term co-interventions through which fish drying practices can be more effectively improvised upon and up scaled. The essay lays out detailed insights and sensible recommendations from the knowledge co-production workshop, organized as a part of solution-focused participatory research on climate-resilient and gender-aware dried fish practices in the Indian Sundarbans. In light of the collective observations on the complex problems and reflections on needs-driven initiatives, the authors advocate for collaborative research praxes in forging just transitions for the less explored dried fish sector.
{"title":"Analyzing scenarios and designing initiatives toward just transitions: coproducing knowledge with(in) the dried fish sector in the Indian Sundarbans","authors":"Raktima Ghosh, Jenia Mukherjee, Aishik Bandyopadhyay, S. Chatterjee, Anuradha Choudry, Poulami Ghosh, Souradip Pathak, Amrita Sen, Priyadarsini Sinha","doi":"10.3389/frwa.2023.1043628","DOIUrl":"https://doi.org/10.3389/frwa.2023.1043628","url":null,"abstract":"The south-western fringe of the Indian Sundarbans hosts a number of fish drying collectives that are exposed to a bundle of mutually reinforcing social-ecological-institutional risks. Despite its wide contribution to local-regional food security and livelihoods, dried fish production has received little attention in research and policy circles so far. As part of the Social Sciences and Humanities Research Council (SSHRC) sponsored Dried Fish Matters global partnership project, our research team seeks to address this lack in two ways: (i) delineating knowledge base through a systematic literature review on intersecting social-ecological and sociohydrological dimensions of integrated fisheries and fish drying practices, and (ii) employing a knowledge co-production approach that involves participation of dry-fishers, researchers, fishworkers' forum (partner organization), and scientists for meaningful understandings about the constraints and potentials in the sector. In this essay, we applied a three-step methodology to arrive at a crisscrossing conceptual, empirical, and collective understandings on the 'invisible' dried fish value chain in the Indian Sundarbans. With detailed lessons from the field, our interdisciplinary research team acts as a liaison among the groups to build a collaborative space for interactions, recognize prevalent adaptive practices and identify pathways toward short-, intermediate-, and long-term co-interventions through which fish drying practices can be more effectively improvised upon and up scaled. The essay lays out detailed insights and sensible recommendations from the knowledge co-production workshop, organized as a part of solution-focused participatory research on climate-resilient and gender-aware dried fish practices in the Indian Sundarbans. In light of the collective observations on the complex problems and reflections on needs-driven initiatives, the authors advocate for collaborative research praxes in forging just transitions for the less explored dried fish sector.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43074060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-06DOI: 10.3389/frwa.2023.1213047
O. Gharsallah, M. Rienzner, A. Mayer, Darya Tkachenko, S. Corsi, Rina Vuciterna, M. Romani, A. Ricciardelli, Elisa Cadei, M. Trevisan, L. Lamastra, A. Tediosi, D. Voccia, A. Facchi
Italy is Europe's leading rice producer, with over half of total production almost totally concentrated in the north-western part of the Padana plain. In this area, rice irrigation has traditionally been carried out by wet seeding and continuous flooding. The replacement of this technique with the dry seeding and delayed flooding in the last 15 years brought economic benefits to farmers but also strong impacts to the water resource system of the area, characterized by a strong interaction between irrigation and shallow aquifer levels. Wet seeding and Alternate Wetting and Drying (AWD) could be seen as an alternative irrigation strategy; however, its environmental, economic and social sustainability must be investigated before supporting the dissemination of this “water-saving” irrigation technique over the territory in cooperation with decision-makers and water resource managers. In this paper, the results of an experimental activity carried out in a platform established in the main Italian rice district to compare three irrigation strategies (wet seeding and traditional flooding—WFL, dry seeding and delayed flooding from around the 3-leaf stage—DFL, wet seeding and alternated wetting and drying from the tillering stage—AWD) and data further provided by the farm holder (agronomic inputs and economic costs for the three options) were used to assess their economic and environmental sustainability through an assessment procedure based on quantitative indicators. Interviews with rice growers in the area were used to identify barriers to the adoption of AWD and subsequently propose ways to overcome them. AWD proved to be economically viable and to reduce the irrigation need in the peak month (June) without significantly affecting rice yield or quality (cadmium and arsenic content in rice grain). Additionally, it guarantees the recharging of the phreatic aquifer in the first period of the irrigation season, while reducing the methane (CH4) emissions, facing another significant environmental challenge of rice cultivation. Rice growers in the region stated their willingness to adopt AWD, although they would need technical, technological and financial support. The assessment procedure adopted in this paper proved to be effective for comparing rice irrigation techniques and is available for further studies.
{"title":"Economic, environmental, and social sustainability of Alternate Wetting and Drying irrigation for rice in northern Italy","authors":"O. Gharsallah, M. Rienzner, A. Mayer, Darya Tkachenko, S. Corsi, Rina Vuciterna, M. Romani, A. Ricciardelli, Elisa Cadei, M. Trevisan, L. Lamastra, A. Tediosi, D. Voccia, A. Facchi","doi":"10.3389/frwa.2023.1213047","DOIUrl":"https://doi.org/10.3389/frwa.2023.1213047","url":null,"abstract":"Italy is Europe's leading rice producer, with over half of total production almost totally concentrated in the north-western part of the Padana plain. In this area, rice irrigation has traditionally been carried out by wet seeding and continuous flooding. The replacement of this technique with the dry seeding and delayed flooding in the last 15 years brought economic benefits to farmers but also strong impacts to the water resource system of the area, characterized by a strong interaction between irrigation and shallow aquifer levels. Wet seeding and Alternate Wetting and Drying (AWD) could be seen as an alternative irrigation strategy; however, its environmental, economic and social sustainability must be investigated before supporting the dissemination of this “water-saving” irrigation technique over the territory in cooperation with decision-makers and water resource managers. In this paper, the results of an experimental activity carried out in a platform established in the main Italian rice district to compare three irrigation strategies (wet seeding and traditional flooding—WFL, dry seeding and delayed flooding from around the 3-leaf stage—DFL, wet seeding and alternated wetting and drying from the tillering stage—AWD) and data further provided by the farm holder (agronomic inputs and economic costs for the three options) were used to assess their economic and environmental sustainability through an assessment procedure based on quantitative indicators. Interviews with rice growers in the area were used to identify barriers to the adoption of AWD and subsequently propose ways to overcome them. AWD proved to be economically viable and to reduce the irrigation need in the peak month (June) without significantly affecting rice yield or quality (cadmium and arsenic content in rice grain). Additionally, it guarantees the recharging of the phreatic aquifer in the first period of the irrigation season, while reducing the methane (CH4) emissions, facing another significant environmental challenge of rice cultivation. Rice growers in the region stated their willingness to adopt AWD, although they would need technical, technological and financial support. The assessment procedure adopted in this paper proved to be effective for comparing rice irrigation techniques and is available for further studies.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43998278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-05DOI: 10.3389/frwa.2023.1087108
R. Danczak, V. Garayburu-Caruso, L. Renteria, Sophia A. McKever, Opal C. Otenburg, S. Grieger, Kyongho Son, M. Kaufman, Stephanie Fulton, J. A. Roebuck, A. Myers‐Pigg, J. Stegen
A large amount of dissolved organic matter (DOM) is transported to the ocean from terrestrial inputs each year (~0.95 Pg C per year) and undergoes a series of abiotic and biotic reactions, causing a significant release of CO2. Combined, these reactions result in variable DOM characteristics (e.g., nominal oxidation state of carbon, double-bond equivalents, chemodiversity) which have demonstrated impacts on biogeochemistry and ecosystem function. Despite this importance, however, comparatively few studies focus on the drivers for DOM chemodiversity along a riverine continuum. Here, we characterized DOM within samples collected from a stream network in the Yakima River Basin using ultrahigh-resolution mass spectrometry (i.e., FTICR-MS). To link DOM chemistry to potential function, we identified putative biochemical transformations within each sample. We also used various molecular characteristics (e.g., thermodynamic favorability, degradability) to calculate a series of functional diversity metrics. We observed that the diversity of biochemical transformations increased with increasing upstream catchment area and landcover. This increase was also connected to expanding functional diversity of the molecular formula. This pattern suggests that as molecular formulas become more diverse in thermodynamics or degradability, there is increased opportunity for biochemical transformations, potentially creating a self-reinforcing cycle where transformations in turn increase diversity and diversity increase transformations. We also observed that these patterns are, in part, connected to landcover whereby the occurrence of many landcover types (e.g., agriculture, urban, forest, shrub) could expand DOM functional diversity. For example, we observed that a novel functional diversity metric measuring similarity to common freshwater molecular formulas (i.e., carboxyl-rich alicyclic molecules) was significantly related to urban coverage. These results show that DOM diversity does not decrease along stream networks, as predicted by a common conceptual model known as the River Continuum Concept, but rather are influenced by the thermodynamic and degradation potential of molecular formula within the DOM, as well as landcover patterns.
大量溶解的有机物(DOM)每年从陆地输入输送到海洋(~0.95 Pg C /年)，并经历一系列的非生物和生物反应，造成大量的CO2释放。综上所述，这些反应产生了不同的DOM特征(例如碳的标称氧化态、双键当量、化学多样性)，这些特征已经证明对生物地球化学和生态系统功能有影响。然而，尽管如此，相对较少的研究关注沿河流连续体DOM化学多样性的驱动因素。在这里，我们使用超高分辨率质谱(即FTICR-MS)对从亚基马河流域的河流网络中收集的样品中的DOM进行了表征。为了将DOM化学与潜在功能联系起来，我们确定了每个样品中假定的生化转化。我们还使用不同的分子特性(例如，热力学有利性，可降解性)来计算一系列功能多样性指标。生物化学转化的多样性随着上游流域面积和土地覆被的增加而增加。这种增加也与分子式功能多样性的扩大有关。这种模式表明，当分子式在热力学或可降解性方面变得更加多样化时，生化转化的机会就会增加，从而可能形成一个自我强化的循环，在这个循环中，转化反过来增加多样性，多样性又增加转化。我们还观察到，这些模式在一定程度上与土地覆盖有关，许多土地覆盖类型(如农业、城市、森林、灌木)的出现可以扩大DOM的功能多样性。例如，我们观察到一种新的功能多样性度量与常见淡水分子式(即富含羧基的脂环分子)的相似性与城市覆盖率显著相关。这些结果表明，DOM多样性并不像河流连续统概念(River Continuum Concept)所预测的那样，沿着河流网络减少，而是受到DOM内部分子式的热力学和降解潜力以及土地覆盖模式的影响。
{"title":"Riverine organic matter functional diversity increases with catchment size","authors":"R. Danczak, V. Garayburu-Caruso, L. Renteria, Sophia A. McKever, Opal C. Otenburg, S. Grieger, Kyongho Son, M. Kaufman, Stephanie Fulton, J. A. Roebuck, A. Myers‐Pigg, J. Stegen","doi":"10.3389/frwa.2023.1087108","DOIUrl":"https://doi.org/10.3389/frwa.2023.1087108","url":null,"abstract":"A large amount of dissolved organic matter (DOM) is transported to the ocean from terrestrial inputs each year (~0.95 Pg C per year) and undergoes a series of abiotic and biotic reactions, causing a significant release of CO2. Combined, these reactions result in variable DOM characteristics (e.g., nominal oxidation state of carbon, double-bond equivalents, chemodiversity) which have demonstrated impacts on biogeochemistry and ecosystem function. Despite this importance, however, comparatively few studies focus on the drivers for DOM chemodiversity along a riverine continuum. Here, we characterized DOM within samples collected from a stream network in the Yakima River Basin using ultrahigh-resolution mass spectrometry (i.e., FTICR-MS). To link DOM chemistry to potential function, we identified putative biochemical transformations within each sample. We also used various molecular characteristics (e.g., thermodynamic favorability, degradability) to calculate a series of functional diversity metrics. We observed that the diversity of biochemical transformations increased with increasing upstream catchment area and landcover. This increase was also connected to expanding functional diversity of the molecular formula. This pattern suggests that as molecular formulas become more diverse in thermodynamics or degradability, there is increased opportunity for biochemical transformations, potentially creating a self-reinforcing cycle where transformations in turn increase diversity and diversity increase transformations. We also observed that these patterns are, in part, connected to landcover whereby the occurrence of many landcover types (e.g., agriculture, urban, forest, shrub) could expand DOM functional diversity. For example, we observed that a novel functional diversity metric measuring similarity to common freshwater molecular formulas (i.e., carboxyl-rich alicyclic molecules) was significantly related to urban coverage. These results show that DOM diversity does not decrease along stream networks, as predicted by a common conceptual model known as the River Continuum Concept, but rather are influenced by the thermodynamic and degradation potential of molecular formula within the DOM, as well as landcover patterns.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46789823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-05DOI: 10.3389/frwa.2023.1196465
K. Lohse
The critical zone has been the subject of much discussion and debate as a term in the ecosystem, soil and earth system science communities, and there is a need to reconcile how this term is used within these disciplines. I suggest that much like watershed and soil ecosystems, the critical zone is an ecosystem and is defined by deeper spatial and temporal boundaries to study its structure and function. Critical zone science, however, expands the scope of ecosystem and soil science and more fully embraces the integration of earth sciences, ecology, and hydrology to understand key mechanisms driving critical zone functions in a place-based setting. This integration of multiple perspectives and expertise is imperative to make new discoveries at the interface of these disciplines. I offer solid examples highlighting how critical zone science as an integrative science contributes to ecosystem and soil sciences and exemplify this emerging field.
{"title":"Reconciling critical zone science with ecosystem and soil science—a personal-scientist perspective","authors":"K. Lohse","doi":"10.3389/frwa.2023.1196465","DOIUrl":"https://doi.org/10.3389/frwa.2023.1196465","url":null,"abstract":"The critical zone has been the subject of much discussion and debate as a term in the ecosystem, soil and earth system science communities, and there is a need to reconcile how this term is used within these disciplines. I suggest that much like watershed and soil ecosystems, the critical zone is an ecosystem and is defined by deeper spatial and temporal boundaries to study its structure and function. Critical zone science, however, expands the scope of ecosystem and soil science and more fully embraces the integration of earth sciences, ecology, and hydrology to understand key mechanisms driving critical zone functions in a place-based setting. This integration of multiple perspectives and expertise is imperative to make new discoveries at the interface of these disciplines. I offer solid examples highlighting how critical zone science as an integrative science contributes to ecosystem and soil sciences and exemplify this emerging field.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42299036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-04DOI: 10.3389/frwa.2023.1169701
Firnaaz Ahamed, Y. You, A. Burgin, J. Stegen, Timothy Scheibe, Hyun‐Seob Song
Microbial decomposition of organic matter (OM) in river corridors is a major driver of nutrient and energy cycles in natural ecosystems. Recent advances in omics technologies enabled high-throughput generation of molecular data that could be used to inform biogeochemical models. With ultrahigh-resolution OM data becoming more readily available, in particular, the substrate-explicit thermodynamic modeling (SXTM) has emerged as a promising approach due to its ability to predict OM degradation and respiration rates from chemical formulae of compounds. This model implicitly assumes that all detected organic compounds are bioavailable, and that aerobic respiration is driven solely by thermodynamics. Despite promising demonstrations in previous studies, these assumptions may not be universally valid because OM degradation is a complex process governed by multiple factors. To identify key drivers of OM respiration, we performed a comprehensive analysis of diverse river systems using Fourier-transform ion cyclotron resonance mass spectrometry OM data and associated respiration measurements collected by the Worldwide Hydrobiogeochemistry Observation Network for Dynamic River Systems (WHONDRS) consortium. In support of our argument, we found that the incorporation of all compounds detected in the samples into the SXTM resulted in a poor correlation between the predicted and measured respiration rates. The data-model consistency was significantly improved by the selective use of a small subset (i.e., only about 5%) of organic compounds identified using an optimization method. Through a subsequent comparative analysis of the subset of compounds (which we presume as bioavailable) against the full set of compounds, we identified three major traits that potentially determine OM bioavailability, including: (1) thermodynamic favorability of aerobic respiration, (2) the number of C atoms contained in compounds, and (2) carbon/nitrogen (C/N) ratio. We found that all three factors serve as “filters” in that the compounds with undesirable properties in any of these traits are strictly excluded from the bioavailable fraction. This work highlights the importance of accounting for the complex interplay among multiple key traits to increase the predictive power of biogeochemical and ecosystem models.
{"title":"Exploring the determinants of organic matter bioavailability through substrate-explicit thermodynamic modeling","authors":"Firnaaz Ahamed, Y. You, A. Burgin, J. Stegen, Timothy Scheibe, Hyun‐Seob Song","doi":"10.3389/frwa.2023.1169701","DOIUrl":"https://doi.org/10.3389/frwa.2023.1169701","url":null,"abstract":"Microbial decomposition of organic matter (OM) in river corridors is a major driver of nutrient and energy cycles in natural ecosystems. Recent advances in omics technologies enabled high-throughput generation of molecular data that could be used to inform biogeochemical models. With ultrahigh-resolution OM data becoming more readily available, in particular, the substrate-explicit thermodynamic modeling (SXTM) has emerged as a promising approach due to its ability to predict OM degradation and respiration rates from chemical formulae of compounds. This model implicitly assumes that all detected organic compounds are bioavailable, and that aerobic respiration is driven solely by thermodynamics. Despite promising demonstrations in previous studies, these assumptions may not be universally valid because OM degradation is a complex process governed by multiple factors. To identify key drivers of OM respiration, we performed a comprehensive analysis of diverse river systems using Fourier-transform ion cyclotron resonance mass spectrometry OM data and associated respiration measurements collected by the Worldwide Hydrobiogeochemistry Observation Network for Dynamic River Systems (WHONDRS) consortium. In support of our argument, we found that the incorporation of all compounds detected in the samples into the SXTM resulted in a poor correlation between the predicted and measured respiration rates. The data-model consistency was significantly improved by the selective use of a small subset (i.e., only about 5%) of organic compounds identified using an optimization method. Through a subsequent comparative analysis of the subset of compounds (which we presume as bioavailable) against the full set of compounds, we identified three major traits that potentially determine OM bioavailability, including: (1) thermodynamic favorability of aerobic respiration, (2) the number of C atoms contained in compounds, and (2) carbon/nitrogen (C/N) ratio. We found that all three factors serve as “filters” in that the compounds with undesirable properties in any of these traits are strictly excluded from the bioavailable fraction. This work highlights the importance of accounting for the complex interplay among multiple key traits to increase the predictive power of biogeochemical and ecosystem models.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48303722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-03DOI: 10.3389/frwa.2023.1119951
Benjamin Meyer, M. Pannekens, A. Soares, Lara I. Timmermann, Alexander J. Probst, M. Hippelein, B. Bendinger, A. Nocker
Drinking water enters buildings with a given microbiological community composition. Within premise plumbing systems, the drinking water is subject to very different conditions and temperatures. Whereas part of the water stays cold, another part is heated to provide hot water. In this study, drinking water samples were taken at different locations in four buildings that had central heating circles and that were equipped with ultrafiltration modules. The latter were intended to keep bacterial numbers low. When studying the increase in bacterial concentrations in these water samples using regrowth tests at different incubation temperatures, a temperature-dependence could be observed. Bacteria in cold water samples propagated best when incubated at 22°C, but often poorly at 36°C and not at all at 50°C. Bacteria in hot water samples showed the reverse behavior and grew best when incubated at 50°C, whereas growth at 22°C was poor or associated with a long growth lag. Water samples from distal taps in periphery locations used for retrieving both cold and hot water showed intermediate growth behaviors. Results suggest the existence of different temperature-adapted bacterial populations within domestic drinking water systems. The finding was supported by sequence data revealing distinct differences in the microbiomes between cold and hot water samples. Abundant bacterial groups in hot water included Deinococci, Kryptonia, Ignavibacteria, Nitrospiria, Gemmatimonadetes and different genera of Gammaproteobacteria. Stagnation of hot water at 50°C, 55°C, or 60°C furthermore shaped the microbiome in different ways indicating that small temperature differences can have a substantial impact on the bacterial communities. Graphical Abstract
{"title":"Bacterial populations in different parts of domestic drinking water systems are distinct and adapted to the given ambient temperatures","authors":"Benjamin Meyer, M. Pannekens, A. Soares, Lara I. Timmermann, Alexander J. Probst, M. Hippelein, B. Bendinger, A. Nocker","doi":"10.3389/frwa.2023.1119951","DOIUrl":"https://doi.org/10.3389/frwa.2023.1119951","url":null,"abstract":"Drinking water enters buildings with a given microbiological community composition. Within premise plumbing systems, the drinking water is subject to very different conditions and temperatures. Whereas part of the water stays cold, another part is heated to provide hot water. In this study, drinking water samples were taken at different locations in four buildings that had central heating circles and that were equipped with ultrafiltration modules. The latter were intended to keep bacterial numbers low. When studying the increase in bacterial concentrations in these water samples using regrowth tests at different incubation temperatures, a temperature-dependence could be observed. Bacteria in cold water samples propagated best when incubated at 22°C, but often poorly at 36°C and not at all at 50°C. Bacteria in hot water samples showed the reverse behavior and grew best when incubated at 50°C, whereas growth at 22°C was poor or associated with a long growth lag. Water samples from distal taps in periphery locations used for retrieving both cold and hot water showed intermediate growth behaviors. Results suggest the existence of different temperature-adapted bacterial populations within domestic drinking water systems. The finding was supported by sequence data revealing distinct differences in the microbiomes between cold and hot water samples. Abundant bacterial groups in hot water included Deinococci, Kryptonia, Ignavibacteria, Nitrospiria, Gemmatimonadetes and different genera of Gammaproteobacteria. Stagnation of hot water at 50°C, 55°C, or 60°C furthermore shaped the microbiome in different ways indicating that small temperature differences can have a substantial impact on the bacterial communities. Graphical Abstract","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48544272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.3389/frwa.2023.1195029
G. Kopsiaftis, Maria Kaselimi, Eftychios E. Protopapadakis, A. Voulodimos, A. Doulamis, N. Doulamis, A. Mantoglou
In this work we investigate the performance of various lower-fidelity models of seawater intrusion in coastal aquifer management problems. The variable density model is considered as the high-fidelity model and a pumping optimization framework is applied on a hypothetical coastal aquifer system in order to calculate the optimal pumping rates which are used as a benchmark for the lower-fidelity approaches. The examined lower-fidelity models could be classified in two categories: (1) physics-based models, which include several widely used variations of the sharp-interface approximation and (2) machine learning assisted models, which aim to improve the efficiency of the SI approach. The Random Forest method was utilized to create a spatially adaptive correction factor for the original sharp-interface model, which improves its accuracy without compromising its efficiency as a lower-fidelity model. Both the original sharp-interface and Machine Learning assisted model are then tested in a single-fidelity optimization method. The optimal pumping rated which were calculated using the Machine Learning based SI model sufficiently approximate the solution from the variable density model. The Machine Learning assisted approximation seems to be a promising surrogate for the high-fidelity, variable density model and could be utilized in multi-fidelity groundwater management frameworks.
{"title":"Performance comparison of physics-based and machine learning assisted multi-fidelity methods for the management of coastal aquifer systems","authors":"G. Kopsiaftis, Maria Kaselimi, Eftychios E. Protopapadakis, A. Voulodimos, A. Doulamis, N. Doulamis, A. Mantoglou","doi":"10.3389/frwa.2023.1195029","DOIUrl":"https://doi.org/10.3389/frwa.2023.1195029","url":null,"abstract":"In this work we investigate the performance of various lower-fidelity models of seawater intrusion in coastal aquifer management problems. The variable density model is considered as the high-fidelity model and a pumping optimization framework is applied on a hypothetical coastal aquifer system in order to calculate the optimal pumping rates which are used as a benchmark for the lower-fidelity approaches. The examined lower-fidelity models could be classified in two categories: (1) physics-based models, which include several widely used variations of the sharp-interface approximation and (2) machine learning assisted models, which aim to improve the efficiency of the SI approach. The Random Forest method was utilized to create a spatially adaptive correction factor for the original sharp-interface model, which improves its accuracy without compromising its efficiency as a lower-fidelity model. Both the original sharp-interface and Machine Learning assisted model are then tested in a single-fidelity optimization method. The optimal pumping rated which were calculated using the Machine Learning based SI model sufficiently approximate the solution from the variable density model. The Machine Learning assisted approximation seems to be a promising surrogate for the high-fidelity, variable density model and could be utilized in multi-fidelity groundwater management frameworks.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41792669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.3389/frwa.2023.1177684
Masoumeh Moayedi, D. Hayati
The current research aims to identify adaptation strategies adopted by rural women of Fars province in dealing with climate variability. This study is applied in terms of purpose, descriptive-correlational in terms of methodology, and field type in terms of data collection. The statistical population were rural women who were members of agricultural households in Fars province, which have been affected by climatic variability in four climatic zones: cold, mild, hot, and very hot. This study was conducted using survey method. A structured questionnaire was designed and its face and content validities were verified using experts' opinions. The size of the studied sample was estimated using Cochran's formula. For sampling, a combined stratified and cluster sampling method was used. Data were collected from 406 respondents from 32 villages in eight counties of Fars province. Then, the data was analyzed. In total, 43 adaptation strategies of rural women were classified in the form of four categories of strategies for development and diversification of income sources, cost management, social capital management, and environmental stress management. The most important adaptation strategy used by rural women against climatic changes has been the cost management strategy. The use of facilities and loans is the most important strategy among the cost management strategies that can lead to reducing the negative effects of climate variability on rural women. Then, the strategy of development and diversification of income sources, management of social capital, and management of environmental tensions were placed in the second to fourth places of adaptation strategies used by rural women under climate variability. The results of this study indicate that the rural women of Fars province are not only passive victims of climate changes, but they act actively and hope to adapt to sudden climate changes. Using prudent strategies, they employ their experience and expertise to reduce the adverse effects of climate variability.
{"title":"Identifying strategies for adaptation of rural women to climate variability in water scarce areas","authors":"Masoumeh Moayedi, D. Hayati","doi":"10.3389/frwa.2023.1177684","DOIUrl":"https://doi.org/10.3389/frwa.2023.1177684","url":null,"abstract":"The current research aims to identify adaptation strategies adopted by rural women of Fars province in dealing with climate variability. This study is applied in terms of purpose, descriptive-correlational in terms of methodology, and field type in terms of data collection. The statistical population were rural women who were members of agricultural households in Fars province, which have been affected by climatic variability in four climatic zones: cold, mild, hot, and very hot. This study was conducted using survey method. A structured questionnaire was designed and its face and content validities were verified using experts' opinions. The size of the studied sample was estimated using Cochran's formula. For sampling, a combined stratified and cluster sampling method was used. Data were collected from 406 respondents from 32 villages in eight counties of Fars province. Then, the data was analyzed. In total, 43 adaptation strategies of rural women were classified in the form of four categories of strategies for development and diversification of income sources, cost management, social capital management, and environmental stress management. The most important adaptation strategy used by rural women against climatic changes has been the cost management strategy. The use of facilities and loans is the most important strategy among the cost management strategies that can lead to reducing the negative effects of climate variability on rural women. Then, the strategy of development and diversification of income sources, management of social capital, and management of environmental tensions were placed in the second to fourth places of adaptation strategies used by rural women under climate variability. The results of this study indicate that the rural women of Fars province are not only passive victims of climate changes, but they act actively and hope to adapt to sudden climate changes. Using prudent strategies, they employ their experience and expertise to reduce the adverse effects of climate variability.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44162643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-30DOI: 10.3389/frwa.2023.1199632
Grigorios Kyritsakas, J. Boxall, V. Speight
A novel data-driven model for the prediction of bacteriological presence, in the form of total cell counts, in treated water exiting drinking water treatment plants is presented. The model was developed and validated using a year of hourly online flow cytometer data from an operational drinking water treatment plant. Various machine learning methods are compared (random forest, support vector machines, k-Nearest Neighbors, Feed-forward Artificial Neural Network, Long Short Term Memory and RusBoost) and different variables selection approaches are used to improve the model's accuracy. Results indicate that the model could accurately predict total cell counts 12 h ahead for both regression and classification-based forecasts—NSE = 0.96 for the best regression model, using the K-Nearest Neighbors algorithm, and Accuracy = 89.33% for the best classification model, using the combined random forest, K-neighbors and RusBoost algorithms. This forecasting horizon is sufficient to enable proactive operational interventions to improve the treatment processes, thereby helping to ensure safe drinking water.
{"title":"Forecasting bacteriological presence in treated drinking water using machine learning","authors":"Grigorios Kyritsakas, J. Boxall, V. Speight","doi":"10.3389/frwa.2023.1199632","DOIUrl":"https://doi.org/10.3389/frwa.2023.1199632","url":null,"abstract":"A novel data-driven model for the prediction of bacteriological presence, in the form of total cell counts, in treated water exiting drinking water treatment plants is presented. The model was developed and validated using a year of hourly online flow cytometer data from an operational drinking water treatment plant. Various machine learning methods are compared (random forest, support vector machines, k-Nearest Neighbors, Feed-forward Artificial Neural Network, Long Short Term Memory and RusBoost) and different variables selection approaches are used to improve the model's accuracy. Results indicate that the model could accurately predict total cell counts 12 h ahead for both regression and classification-based forecasts—NSE = 0.96 for the best regression model, using the K-Nearest Neighbors algorithm, and Accuracy = 89.33% for the best classification model, using the combined random forest, K-neighbors and RusBoost algorithms. This forecasting horizon is sufficient to enable proactive operational interventions to improve the treatment processes, thereby helping to ensure safe drinking water.","PeriodicalId":33801,"journal":{"name":"Frontiers in Water","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45580874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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