E. Bacmeister, E. Peck, S. Bernasconi, S. Inamdar, J. Kan, Marc Peipoch
{"title":"低阶流域暴风雨期间的水柱氮去除量","authors":"E. Bacmeister, E. Peck, S. Bernasconi, S. Inamdar, J. Kan, Marc Peipoch","doi":"10.1029/2024JG008360","DOIUrl":null,"url":null,"abstract":"<p>Water column removal in streams is a nitrogen (N) cycling pathway that has been historically overlooked. Studies filling this knowledge gap have focused on the role of water column N removal in mid-to-large-order rivers with consistently high suspended sediment concentrations. However, smaller streams may provide comparable suspended sediment concentrations during and after storm events, creating favorable conditions for water column N removal. To assess the presence, magnitude, and control of water column N removal during storms in low-order watersheds, we measured water column denitrification and heterotrophic assimilatory N uptake rates at three locations in a Mid-Atlantic watershed during five storm events of different magnitude, sediment loads, and nutrient availability. We found large variations in water column denitrification (0–5.56 mg N g<sup>−1</sup> d<sup>−1</sup>) and assimilatory uptake (0.003–1.67 mg N g<sup>−1</sup> d<sup>−1</sup>). Higher rates of N removal occurred during flow recession, with a correlation between suspended sediment organic matter content and denitrification. On average, denitrification rates in the water column were higher when flashy responses to storm events occurred. In contrast to denitrification, water column N removal rates (as both denitrification and heterotrophic assimilation) during storm events were comparable to those measured at baseflow in larger rivers. However, water column denitrification could only account for less than 10% of potential reach-scale N removal during most of the storm events. Our findings provide insight into the ecological relevance of small stream water columns and suggest that more research is needed to understand the magnitude of stream water column processing on watershed-scale N removal.</p>","PeriodicalId":16003,"journal":{"name":"Journal of Geophysical Research: Biogeosciences","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Water Column Nitrogen Removal During Storms in a Low-Order Watershed\",\"authors\":\"E. Bacmeister, E. Peck, S. Bernasconi, S. Inamdar, J. Kan, Marc Peipoch\",\"doi\":\"10.1029/2024JG008360\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Water column removal in streams is a nitrogen (N) cycling pathway that has been historically overlooked. Studies filling this knowledge gap have focused on the role of water column N removal in mid-to-large-order rivers with consistently high suspended sediment concentrations. However, smaller streams may provide comparable suspended sediment concentrations during and after storm events, creating favorable conditions for water column N removal. To assess the presence, magnitude, and control of water column N removal during storms in low-order watersheds, we measured water column denitrification and heterotrophic assimilatory N uptake rates at three locations in a Mid-Atlantic watershed during five storm events of different magnitude, sediment loads, and nutrient availability. We found large variations in water column denitrification (0–5.56 mg N g<sup>−1</sup> d<sup>−1</sup>) and assimilatory uptake (0.003–1.67 mg N g<sup>−1</sup> d<sup>−1</sup>). Higher rates of N removal occurred during flow recession, with a correlation between suspended sediment organic matter content and denitrification. On average, denitrification rates in the water column were higher when flashy responses to storm events occurred. In contrast to denitrification, water column N removal rates (as both denitrification and heterotrophic assimilation) during storm events were comparable to those measured at baseflow in larger rivers. However, water column denitrification could only account for less than 10% of potential reach-scale N removal during most of the storm events. Our findings provide insight into the ecological relevance of small stream water columns and suggest that more research is needed to understand the magnitude of stream water column processing on watershed-scale N removal.</p>\",\"PeriodicalId\":16003,\"journal\":{\"name\":\"Journal of Geophysical Research: Biogeosciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.7000,\"publicationDate\":\"2024-10-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geophysical Research: Biogeosciences\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1029/2024JG008360\",\"RegionNum\":3,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Biogeosciences","FirstCategoryId":"93","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1029/2024JG008360","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
摘要
溪流中的水体脱氮是一种氮(N)循环途径,但历来被忽视。填补这一知识空白的研究主要集中在悬浮泥沙浓度持续较高的中大型河流中水体脱氮的作用。然而,较小的河流可能会在暴雨期间和暴雨后提供相当的悬浮泥沙浓度,从而为水体脱氮创造有利条件。为了评估低阶流域风暴期间水体氮去除的存在、规模和控制情况,我们在大西洋中部流域的三个地点测量了五次不同规模、沉积物负荷和营养供应的风暴期间的水体反硝化作用和异养同化氮吸收率。我们发现,水体脱氮(0-5.56 毫克 N g-1 d-1)和同化吸收(0.003-1.67 毫克 N g-1 d-1)的变化很大。水流衰退期的脱氮率较高,悬浮沉积物有机质含量与反硝化作用之间存在相关性。平均而言,当暴雨事件发生时,水体中的反硝化率较高。与反硝化作用相反,暴雨事件期间的水体氮去除率(包括反硝化作用和异养同化作用)与大河基流测量值相当。然而,在大多数暴雨事件中,水体反硝化作用只能占潜在到达尺度氮去除率的不到 10%。我们的研究结果让我们深入了解了小河流水体的生态相关性,并建议需要开展更多研究,以了解河流水体处理对流域尺度氮去除的影响程度。
Water Column Nitrogen Removal During Storms in a Low-Order Watershed
Water column removal in streams is a nitrogen (N) cycling pathway that has been historically overlooked. Studies filling this knowledge gap have focused on the role of water column N removal in mid-to-large-order rivers with consistently high suspended sediment concentrations. However, smaller streams may provide comparable suspended sediment concentrations during and after storm events, creating favorable conditions for water column N removal. To assess the presence, magnitude, and control of water column N removal during storms in low-order watersheds, we measured water column denitrification and heterotrophic assimilatory N uptake rates at three locations in a Mid-Atlantic watershed during five storm events of different magnitude, sediment loads, and nutrient availability. We found large variations in water column denitrification (0–5.56 mg N g−1 d−1) and assimilatory uptake (0.003–1.67 mg N g−1 d−1). Higher rates of N removal occurred during flow recession, with a correlation between suspended sediment organic matter content and denitrification. On average, denitrification rates in the water column were higher when flashy responses to storm events occurred. In contrast to denitrification, water column N removal rates (as both denitrification and heterotrophic assimilation) during storm events were comparable to those measured at baseflow in larger rivers. However, water column denitrification could only account for less than 10% of potential reach-scale N removal during most of the storm events. Our findings provide insight into the ecological relevance of small stream water columns and suggest that more research is needed to understand the magnitude of stream water column processing on watershed-scale N removal.
期刊介绍:
JGR-Biogeosciences focuses on biogeosciences of the Earth system in the past, present, and future and the extension of this research to planetary studies. The emerging field of biogeosciences spans the intellectual interface between biology and the geosciences and attempts to understand the functions of the Earth system across multiple spatial and temporal scales. Studies in biogeosciences may use multiple lines of evidence drawn from diverse fields to gain a holistic understanding of terrestrial, freshwater, and marine ecosystems and extreme environments. Specific topics within the scope of the section include process-based theoretical, experimental, and field studies of biogeochemistry, biogeophysics, atmosphere-, land-, and ocean-ecosystem interactions, biomineralization, life in extreme environments, astrobiology, microbial processes, geomicrobiology, and evolutionary geobiology