Pub Date : 2024-03-16DOI: 10.1007/s10533-024-01122-6
Emilie Gios, Erik Verbruggen, Joachim Audet, Rachel Burns, Klaus Butterbach-Bahl, Mikk Espenberg, Christian Fritz, Stephan Glatzel, Gerald Jurasinski, Tuula Larmola, Ülo Mander, Claudia Nielsen, Andres F. Rodriguez, Clemens Scheer, Dominik Zak, Hanna M. Silvennoinen
Restoration of drained peatlands through rewetting has recently emerged as a prevailing strategy to mitigate excessive greenhouse gas emissions and re-establish the vital carbon sequestration capacity of peatlands. Rewetting can help to restore vegetation communities and biodiversity, while still allowing for extensive agricultural management such as paludiculture. Belowground processes governing carbon fluxes and greenhouse gas dynamics are mediated by a complex network of microbial communities and processes. Our understanding of this complexity and its multi-factorial controls in rewetted peatlands is limited. Here, we summarize the research regarding the role of soil microbial communities and functions in driving carbon and nutrient cycling in rewetted peatlands including the use of molecular biology techniques in understanding biogeochemical processes linked to greenhouse gas fluxes. We emphasize that rapidly advancing molecular biology approaches, such as high-throughput sequencing, are powerful tools helping to elucidate the dynamics of key biogeochemical processes when combined with isotope tracing and greenhouse gas measuring techniques. Insights gained from the gathered studies can help inform efficient monitoring practices for rewetted peatlands and the development of climate-smart restoration and management strategies.
{"title":"Unraveling microbial processes involved in carbon and nitrogen cycling and greenhouse gas emissions in rewetted peatlands by molecular biology","authors":"Emilie Gios, Erik Verbruggen, Joachim Audet, Rachel Burns, Klaus Butterbach-Bahl, Mikk Espenberg, Christian Fritz, Stephan Glatzel, Gerald Jurasinski, Tuula Larmola, Ülo Mander, Claudia Nielsen, Andres F. Rodriguez, Clemens Scheer, Dominik Zak, Hanna M. Silvennoinen","doi":"10.1007/s10533-024-01122-6","DOIUrl":"10.1007/s10533-024-01122-6","url":null,"abstract":"<div><p>Restoration of drained peatlands through rewetting has recently emerged as a prevailing strategy to mitigate excessive greenhouse gas emissions and re-establish the vital carbon sequestration capacity of peatlands. Rewetting can help to restore vegetation communities and biodiversity, while still allowing for extensive agricultural management such as paludiculture. Belowground processes governing carbon fluxes and greenhouse gas dynamics are mediated by a complex network of microbial communities and processes. Our understanding of this complexity and its multi-factorial controls in rewetted peatlands is limited. Here, we summarize the research regarding the role of soil microbial communities and functions in driving carbon and nutrient cycling in rewetted peatlands including the use of molecular biology techniques in understanding biogeochemical processes linked to greenhouse gas fluxes. We emphasize that rapidly advancing molecular biology approaches, such as high-throughput sequencing, are powerful tools helping to elucidate the dynamics of key biogeochemical processes when combined with isotope tracing and greenhouse gas measuring techniques. Insights gained from the gathered studies can help inform efficient monitoring practices for rewetted peatlands and the development of climate-smart restoration and management strategies.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 4","pages":"609 - 629"},"PeriodicalIF":3.9,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01122-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140139405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-13DOI: 10.1007/s10533-024-01128-0
S. F. Starr, B. Mortazavi, C. Tatariw, K. A. Kuehn, J. A. Cherry, T. Ledford, E. Smyth, A. Griffin Wood, S. E. Sebren
Coastal marshes mitigate allochthonous nitrogen (N) inputs to adjacent marine habitat; however, their extent is declining rapidly. As a result, marsh restoration and construction have become a major foci of wetland management. Constructed marshes can quickly reach similar plant biomass to natural marshes, but biogeochemical functions like N removal and retention can take decades to reach functional equivalency, often due to lags in organic matter (OM) pools development in newly constructed marshes. We compared denitrification and dissimilatory nitrate reduction to ammonium (DNRA) rates in a 32 year-old constructed marsh and adjacent reference marsh in the Northern Gulf of Mexico. Marsh sediments packed into 3 mm “thin discs” were subjected to three OM quality treatments (no OM addition, labile OM, or recalcitrant OM) and two N treatments (ambient nitrate or elevated nitrate) during a 13 day incubation. We found that OM addition, rather than marsh type or nitrate treatment, was the most important driver of nitrate reduction, increasing both denitrification and DNRA and promoting DNRA over denitrification in both marshes. Fungal and bacterial biomass were higher in the natural marsh across treatments, but recalcitrant OM increased fungal biomass in the constructed marsh, suggesting OM-limitation of fungal growth. We found that constructed marshes are capable of similar denitrification and DNRA as natural marshes after 30 years, and that labile OM addition promotes N retention in both natural and constructed marshes.
Graphical Abstract
Conceptual figure highlighting the findings of this experiment. Under control treatment with no C addition (bottom panel), constructed and natural marshes have similar rates of both DNRA and denitrification. The natural marsh has higher fungal and bacterial biomass, while fungal biomass is not detectable in the constructed marsh. Under labile OM additions (upper left panel), rates of both DNRA and denitrification are increased and DNRA becomes favored over denitrification in both marshes. Recalcitrant OM additions (upper right) increase denitrification, but do not affect DNRA or % denitrification. The addition of recalcitrant OM also increases the detectability of fungal biomass in the constructed marsh.
沿海沼泽可减轻邻近海洋生境的同源氮(N)输入,但其范围正在迅速缩小。因此,恢复和建造沼泽已成为湿地管理的主要重点。人造沼泽可以很快达到与天然沼泽相似的植物生物量,但生物地球化学功能(如氮的去除和保留)可能需要几十年才能达到功能等效,这通常是由于新建沼泽的有机物(OM)池发展滞后造成的。我们比较了墨西哥湾北部一个建有 32 年的沼泽和邻近参照沼泽的反硝化率和硝酸盐还原氨(DNRA)率。在为期 13 天的培养过程中,将沼泽沉积物包装成 3 毫米的 "薄盘",对其进行了三种 OM 质量处理(不添加 OM、易变 OM 或难分解 OM)和两种 N 处理(环境硝酸盐或硝酸盐升高)。我们发现,添加 OM(而不是沼泽类型或硝酸盐处理)是硝酸盐还原的最重要驱动因素,它同时增加了反硝化和 DNRA,并在两个沼泽中促进 DNRA 而不是反硝化。在各种处理中,天然沼泽中的真菌和细菌生物量较高,但在人工沼泽中,难分解有机物增加了真菌生物量,这表明有机物限制了真菌的生长。我们发现,30 年后,人工沼泽的反硝化能力和 DNRA 与天然沼泽相似,而添加易腐有机物可促进天然沼泽和人工沼泽的氮保留。在不添加碳的对照处理下(下图),人工沼泽和天然沼泽的 DNRA 和反硝化率相似。天然沼泽的真菌和细菌生物量较高,而在人工建造的沼泽中则检测不到真菌生物量。在添加易腐 OM 的情况下(左上图),两个沼泽的 DNRA 和反硝化速率都会增加,DNRA 比反硝化更有利。添加难降解有机物(右上图)会增加反硝化作用,但不会影响 DNRA 或反硝化率。添加难降解 OM 还会增加构建沼泽中真菌生物量的可探测性。
{"title":"Labile organic matter promotes nitrogen retention in natural and constructed gulf coast marshes","authors":"S. F. Starr, B. Mortazavi, C. Tatariw, K. A. Kuehn, J. A. Cherry, T. Ledford, E. Smyth, A. Griffin Wood, S. E. Sebren","doi":"10.1007/s10533-024-01128-0","DOIUrl":"10.1007/s10533-024-01128-0","url":null,"abstract":"<div><p>Coastal marshes mitigate allochthonous nitrogen (N) inputs to adjacent marine habitat; however, their extent is declining rapidly. As a result, marsh restoration and construction have become a major foci of wetland management. Constructed marshes can quickly reach similar plant biomass to natural marshes, but biogeochemical functions like N removal and retention can take decades to reach functional equivalency, often due to lags in organic matter (OM) pools development in newly constructed marshes. We compared denitrification and dissimilatory nitrate reduction to ammonium (DNRA) rates in a 32 year-old constructed marsh and adjacent reference marsh in the Northern Gulf of Mexico. Marsh sediments packed into 3 mm “thin discs” were subjected to three OM quality treatments (no OM addition, labile OM, or recalcitrant OM) and two N treatments (ambient nitrate or elevated nitrate) during a 13 day incubation. We found that OM addition, rather than marsh type or nitrate treatment, was the most important driver of nitrate reduction, increasing both denitrification and DNRA and promoting DNRA over denitrification in both marshes. Fungal and bacterial biomass were higher in the natural marsh across treatments, but recalcitrant OM increased fungal biomass in the constructed marsh, suggesting OM-limitation of fungal growth. We found that constructed marshes are capable of similar denitrification and DNRA as natural marshes after 30 years, and that labile OM addition promotes N retention in both natural and constructed marshes.</p><h3>Graphical Abstract</h3><p>Conceptual figure highlighting the findings of this experiment. Under control treatment with no C addition (bottom panel), constructed and natural marshes have similar rates of both DNRA and denitrification. The natural marsh has higher fungal and bacterial biomass, while fungal biomass is not detectable in the constructed marsh. Under labile OM additions (upper left panel), rates of both DNRA and denitrification are increased and DNRA becomes favored over denitrification in both marshes. Recalcitrant OM additions (upper right) increase denitrification, but do not affect DNRA or % denitrification. The addition of recalcitrant OM also increases the detectability of fungal biomass in the constructed marsh.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 3","pages":"269 - 285"},"PeriodicalIF":3.9,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01128-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140124081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-13DOI: 10.1007/s10533-024-01130-6
Julia Pasqualini, Daniel Graeber, Alexander Bartusch, Steffen Kümmel, Zulma Lorena Duran Hernandez, Niculina Musat, Nergui Sunjidmaa, Markus Weitere, Mario Brauns
Agricultural land use alters nitrate (NO3–) uptake dynamics in streams, but the specific mechanisms linking individual agricultural stressors to benthic and hyporheic uptake remain unclear. Using stream-side mesocosms and 15N-nitrate additions, we examined the individual and combined effects of fine sediment (FS) and augmented light and phosphorus levels (L&P) on benthic and hyporheic NO3– uptake rates. In absence of FS, L&P stimulated uptake of autotrophic and heterotrophic biofilms, leading to a 12- and 7-fold increase in the benthic and hyporheic compartments, respectively. Under ambient light and nutrient conditions, FS reduced by 3-fold benthic uptake, but effects were not significant. Conversely, in the hyporheic compartment, FS induced anoxic conditions, likely stimulating denitrification and causing a 14-fold increase in hyporheic uptake. When these stressors were combined, they did not interact in the benthic compartment. Conversely, in the hyporheic compartment they interacted antagonistically, with L&P diminishing the increase in uptake induced by FS. Our results indicate that the previously observed increase of whole-stream NO3– uptake in agricultural streams is attributable to nutrients and light stimulating benthic uptake, while fine sediment effects and the role of the hyporheic compartment to total uptake are modest. Moreover, the finding that stressor interactions vary with ecosystem compartments calls for a consideration of all compartments and their contribution to whole-system functioning in multiple stressor studies. We are beginning to understand how multiple interacting stressors affect stream functioning, but more mechanistic evidence is needed to disentangle whether additive or non-additive effects prevail in human-altered ecosystems.
{"title":"Disentangling effects of multiple agricultural stressors on benthic and hyporheic nitrate uptake","authors":"Julia Pasqualini, Daniel Graeber, Alexander Bartusch, Steffen Kümmel, Zulma Lorena Duran Hernandez, Niculina Musat, Nergui Sunjidmaa, Markus Weitere, Mario Brauns","doi":"10.1007/s10533-024-01130-6","DOIUrl":"10.1007/s10533-024-01130-6","url":null,"abstract":"<div><p>Agricultural land use alters nitrate (NO<sub>3</sub><sup>–</sup>) uptake dynamics in streams, but the specific mechanisms linking individual agricultural stressors to benthic and hyporheic uptake remain unclear. Using stream-side mesocosms and <sup>15</sup>N-nitrate additions, we examined the individual and combined effects of fine sediment (FS) and augmented light and phosphorus levels (L&P) on benthic and hyporheic NO<sub>3</sub><sup>–</sup> uptake rates. In absence of FS, L&P stimulated uptake of autotrophic and heterotrophic biofilms, leading to a 12- and 7-fold increase in the benthic and hyporheic compartments, respectively. Under ambient light and nutrient conditions, FS reduced by 3-fold benthic uptake, but effects were not significant. Conversely, in the hyporheic compartment, FS induced anoxic conditions, likely stimulating denitrification and causing a 14-fold increase in hyporheic uptake. When these stressors were combined, they did not interact in the benthic compartment. Conversely, in the hyporheic compartment they interacted antagonistically, with L&P diminishing the increase in uptake induced by FS. Our results indicate that the previously observed increase of whole-stream NO<sub>3</sub><sup>–</sup> uptake in agricultural streams is attributable to nutrients and light stimulating benthic uptake, while fine sediment effects and the role of the hyporheic compartment to total uptake are modest. Moreover, the finding that stressor interactions vary with ecosystem compartments calls for a consideration of all compartments and their contribution to whole-system functioning in multiple stressor studies. We are beginning to understand how multiple interacting stressors affect stream functioning, but more mechanistic evidence is needed to disentangle whether additive or non-additive effects prevail in human-altered ecosystems.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 3","pages":"287 - 299"},"PeriodicalIF":3.9,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01130-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140114420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-10DOI: 10.1007/s10533-024-01125-3
Idri Hastuty Siregar, Marta Camps-Arbestain, Gabor Kereszturi, Alan Palmer, Miko U. F. Kirschbaum, Tao Wang
Effects of global warming on soil organic carbon (C) can be investigated by comparing sites experiencing different temperatures. However, observations can be affected by covariance of temperature with other environmental properties. Here, we studied a thermal gradient in forest soils derived from volcanic materials on Mount Taranaki (New Zealand) to disentangle the effects of temperature and reactive minerals on soil organic C quantity and composition. We collected soils at four depths and four elevations with mean annual temperatures ranging from 7.3 to 10.5 °C. Soil C stocks were not significantly different across sites (average 162 MgC ha−1 to 85 cm depth, P > .05). Neither aluminium (Al)-complexed C, nor mineral-associated C changed significantly (P > .05) with temperature. The molecular characterisation of soil organic matter showed that plant-derived C declined with increasing temperature, while microbial-processed C increased. Accompanying these changes, soil short-range order (SRO) constituents (including allophane) generally increased with temperature. Results from structural equation modelling revealed that, although a warmer temperature tended to accelerate soil organic C decomposition as inferred from molecular fingerprints, it also exerted a positive effect on soil total C presumably by enhancing plant C input. Despite a close linkage between mineral-associated C and soil organic C, the increased abundance of reactive minerals at 30–85 cm depth with temperature did not increase soil organic C concentration at that depth. We therefore propose that fresh C inputs, rather than reactive minerals, mediate soil C responses to temperature across the thermal gradient of volcanic soils under humid-temperate climatic conditions.
全球变暖对土壤有机碳(C)的影响可以通过比较不同温度的地点来研究。然而,温度与其他环境属性的协变可能会影响观测结果。在此,我们研究了塔拉纳基火山(新西兰)上火山物质形成的森林土壤的热梯度,以厘清温度和活性矿物对土壤有机碳数量和组成的影响。我们采集了四个深度和四个海拔高度的土壤,年平均温度在 7.3 ℃ 至 10.5 ℃ 之间。不同地点的土壤有机碳储量差异不大(85 厘米深度的平均值为 162 MgC ha-1, P > .05)。铝(Al)络合碳和矿物螯合碳均未随温度发生显著变化(P > .05)。土壤有机质的分子特征显示,植物源碳随温度升高而减少,而微生物加工的碳则有所增加。伴随着这些变化,土壤短程阶(SRO)成分(包括异芬烷)普遍随温度升高而增加。结构方程建模的结果表明,虽然根据分子指纹推断,温度升高往往会加速土壤有机碳的分解,但它也会对土壤总碳产生积极影响,这可能是通过增加植物碳的输入来实现的。尽管矿物质相关碳与土壤有机碳之间存在密切联系,但随着温度升高,30-85 厘米深度的活性矿物质丰度增加,并没有增加该深度的土壤有机碳浓度。因此,我们认为,在湿润-温带气候条件下,新鲜 C 输入而非活性矿物介导了火山岩土壤热梯度下土壤 C 对温度的响应。
{"title":"Disentangling the effects of temperature and reactive minerals on soil carbon stocks across a thermal gradient in a temperate native forest ecosystem","authors":"Idri Hastuty Siregar, Marta Camps-Arbestain, Gabor Kereszturi, Alan Palmer, Miko U. F. Kirschbaum, Tao Wang","doi":"10.1007/s10533-024-01125-3","DOIUrl":"10.1007/s10533-024-01125-3","url":null,"abstract":"<div><p>Effects of global warming on soil organic carbon (C) can be investigated by comparing sites experiencing different temperatures. However, observations can be affected by covariance of temperature with other environmental properties. Here, we studied a thermal gradient in forest soils derived from volcanic materials on Mount Taranaki (New Zealand) to disentangle the effects of temperature and reactive minerals on soil organic C quantity and composition. We collected soils at four depths and four elevations with mean annual temperatures ranging from 7.3 to 10.5 °C. Soil C stocks were not significantly different across sites (average 162 MgC ha<sup>−1</sup> to 85 cm depth,<i> P</i> > .05). Neither aluminium (Al)-complexed C, nor mineral-associated C changed significantly (<i>P</i> > .05) with temperature. The molecular characterisation of soil organic matter showed that plant-derived C declined with increasing temperature, while microbial-processed C increased. Accompanying these changes, soil short-range order (SRO) constituents (including allophane) generally increased with temperature. Results from structural equation modelling revealed that, although a warmer temperature tended to accelerate soil organic C decomposition as inferred from molecular fingerprints, it also exerted a positive effect on soil total C presumably by enhancing plant C input. Despite a close linkage between mineral-associated C and soil organic C, the increased abundance of reactive minerals at 30–85 cm depth with temperature did not increase soil organic C concentration at that depth. We therefore propose that fresh C inputs, rather than reactive minerals, mediate soil C responses to temperature across the thermal gradient of volcanic soils under humid-temperate climatic conditions.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 3","pages":"251 - 267"},"PeriodicalIF":3.9,"publicationDate":"2024-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01125-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140096965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-09DOI: 10.1007/s10533-024-01117-3
Linn G. Speidel, Roger Carvalho da Silva, Melanie Beck, Olaf Dellwig, Jochen Wollschläger, Thorsten Dittmar, Michael Seidel
The German Bight in the southern North Sea receives nutrients, dissolved organic matter (DOM), and trace metals from rivers, porewater reflux, and porewater outwelling. We studied the marine, riverine, and porewater sources analyzing molecular transformations of solid-phase extracted (SPE) DOM in the German Bight. We applied a combination of ultrahigh-resolution mass spectrometry (FT-ICR-MS) with quantitative data of dissolved organic sulfur (DOS), dissolved black carbon (DBC), dissolved trace metals (Ba, Co, Gd, Mo, Mn, W), and nutrients (nitrite, nitrate, phosphate, silicate). While aromatic DOM and DBC mainly originated from the rivers, nitrogen-containing, more saturated DOM was enriched offshore suggesting greater contributions of marine (algal) sources. Except for dissolved Mo, rivers were the primary source of trace metals and nutrients. However, tidal flats contributed to dissolved nutrient (e.g., dissolved phosphate), trace metal and DOS inventories of the southern North Sea. The input of DOS from intertidal flats was identified by the molecular index derived from sulfidic porewaters (ISuP), non-conservative behavior of elemental sulfur-to-carbon ratio and sulfur content of molecular formulae (from FT-ICR-MS). Dissolved Mn and Si were removed in the German Bight, likely due to precipitation as Mn(hydr)oxides and biological uptake, respectively. Preliminary estimates suggest that DOS from porewater outwelling is approximately four times higher than DOS discharged by the three main rivers in the region. Our study therefore highlights the need to consider porewater discharge in addition to riverine sources to comprehensively assess elemental budgets within the complex interplay and transformations of DOM, nutrients, and trace metals in coastal ecosystems.
北海南部的德国港湾从河流、孔隙水回流和孔隙水外流中获取营养物质、溶解有机物(DOM)和痕量金属。我们研究了海洋、河流和孔隙水的来源,分析了德国港湾固相萃取(SPE)DOM 的分子转化。我们将超高分辨率质谱法(FT-ICR-MS)与溶解有机硫(DOS)、溶解黑碳(DBC)、溶解痕量金属(钡、钴、钆、钼、锰、钨)和营养物质(亚硝酸盐、硝酸盐、磷酸盐、硅酸盐)的定量数据相结合。芳香族 DOM 和 DBC 主要来源于河流,而含氮、饱和度更高的 DOM 则富集于近海,这表明海洋(藻类)来源的贡献更大。除溶解态 Mo 外,河流是痕量金属和营养物质的主要来源。不过,北海南部的溶解营养物(如溶解磷酸盐)、痕量金属和 DOS 库存也有潮汐滩涂的贡献。潮间带滩涂的 DOS 输入量是通过硫化孔隙水(ISuP)得出的分子指数、元素硫碳比的非保守行为和分子式中的硫含量(来自 FT-ICR-MS)确定的。在德国湾,溶解的锰和硅被去除,可能分别是由于锰(氢)氧化物沉淀和生物吸收。初步估计表明,孔隙水外流的 DOS 约为该地区三条主要河流排放的 DOS 的四倍。因此,我们的研究强调,在全面评估沿岸生态系统中 DOM、营养盐和痕量金属复杂的相互作用和转化过程中的元素预算时,除了考虑河 流来源外,还需要考虑孔隙水排放。
{"title":"Rivers and tidal flats as sources of dissolved organic matter and trace metals in the German Bight (North Sea)","authors":"Linn G. Speidel, Roger Carvalho da Silva, Melanie Beck, Olaf Dellwig, Jochen Wollschläger, Thorsten Dittmar, Michael Seidel","doi":"10.1007/s10533-024-01117-3","DOIUrl":"10.1007/s10533-024-01117-3","url":null,"abstract":"<div><p>The German Bight in the southern North Sea receives nutrients, dissolved organic matter (DOM), and trace metals from rivers, porewater reflux, and porewater outwelling. We studied the marine, riverine, and porewater sources analyzing molecular transformations of solid-phase extracted (SPE) DOM in the German Bight. We applied a combination of ultrahigh-resolution mass spectrometry (FT-ICR-MS) with quantitative data of dissolved organic sulfur (DOS), dissolved black carbon (DBC), dissolved trace metals (Ba, Co, Gd, Mo, Mn, W), and nutrients (nitrite, nitrate, phosphate, silicate). While aromatic DOM and DBC mainly originated from the rivers, nitrogen-containing, more saturated DOM was enriched offshore suggesting greater contributions of marine (algal) sources. Except for dissolved Mo, rivers were the primary source of trace metals and nutrients. However, tidal flats contributed to dissolved nutrient (e.g., dissolved phosphate), trace metal and DOS inventories of the southern North Sea. The input of DOS from intertidal flats was identified by the molecular index derived from sulfidic porewaters (I<sub>SuP</sub>), non-conservative behavior of elemental sulfur-to-carbon ratio and sulfur content of molecular formulae (from FT-ICR-MS). Dissolved Mn and Si were removed in the German Bight, likely due to precipitation as Mn(hydr)oxides and biological uptake, respectively. Preliminary estimates suggest that DOS from porewater outwelling is approximately four times higher than DOS discharged by the three main rivers in the region. Our study therefore highlights the need to consider porewater discharge in addition to riverine sources to comprehensively assess elemental budgets within the complex interplay and transformations of DOM, nutrients, and trace metals in coastal ecosystems.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 3","pages":"225 - 250"},"PeriodicalIF":3.9,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01117-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140096895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-09DOI: 10.1007/s10533-024-01132-4
Patrick Liebmann, Jiří Bárta, Cordula Vogel, Tim Urich, Alexander Kholodov, Milan Varsadiya, Ole Mewes, Stefan Dultz, Muhammad Waqas, Haitao Wang, Olga Shibistova, Georg Guggenberger
Permafrost soils in the northern hemisphere are known to harbor large amounts of soil organic matter (SOM). Global climate warming endangers this stable soil organic carbon (SOC) pool by triggering permafrost thaw and deepening the active layer, while at the same time progressing soil formation. But depending, e.g., on ice content or drainage, conditions in the degraded permafrost can range from water-saturated/anoxic to dry/oxic, with concomitant shifts in SOM stabilizing mechanisms. In this field study in Interior Alaska, we investigated two sites featuring degraded permafrost, one water-saturated and the other well-drained, alongside a third site with intact permafrost. Soil aggregate- and density fractions highlighted that permafrost thaw promoted macroaggregate formation, amplified by the incorporation of particulate organic matter, in topsoils of both degradation sites, thus potentially counteracting a decrease in topsoil SOC induced by the permafrost thawing. However, the subsoils were found to store notably less SOC than the intact permafrost in all fractions of both degradation sites. Our investigations revealed up to net 75% smaller SOC storage in the upper 100 cm of degraded permafrost soils as compared to the intact one, predominantly related to the subsoils, while differences between soils of wet and dry degraded landscapes were minor. This study provides evidence that the consideration of different permafrost degradation landscapes and the employment of soil fractionation techniques is a useful combination to investigate soil development and SOM stabilization processes in this sensitive ecosystem.
{"title":"Permafrost degradation and its consequences for carbon storage in soils of Interior Alaska","authors":"Patrick Liebmann, Jiří Bárta, Cordula Vogel, Tim Urich, Alexander Kholodov, Milan Varsadiya, Ole Mewes, Stefan Dultz, Muhammad Waqas, Haitao Wang, Olga Shibistova, Georg Guggenberger","doi":"10.1007/s10533-024-01132-4","DOIUrl":"10.1007/s10533-024-01132-4","url":null,"abstract":"<div><p>Permafrost soils in the northern hemisphere are known to harbor large amounts of soil organic matter (SOM). Global climate warming endangers this stable soil organic carbon (SOC) pool by triggering permafrost thaw and deepening the active layer, while at the same time progressing soil formation. But depending, e.g., on ice content or drainage, conditions in the degraded permafrost can range from water-saturated/anoxic to dry/oxic, with concomitant shifts in SOM stabilizing mechanisms. In this field study in Interior Alaska, we investigated two sites featuring degraded permafrost, one water-saturated and the other well-drained, alongside a third site with intact permafrost. Soil aggregate- and density fractions highlighted that permafrost thaw promoted macroaggregate formation, amplified by the incorporation of particulate organic matter, in topsoils of both degradation sites, thus potentially counteracting a decrease in topsoil SOC induced by the permafrost thawing. However, the subsoils were found to store notably less SOC than the intact permafrost in all fractions of both degradation sites. Our investigations revealed up to net 75% smaller SOC storage in the upper 100 cm of degraded permafrost soils as compared to the intact one, predominantly related to the subsoils, while differences between soils of wet and dry degraded landscapes were minor. This study provides evidence that the consideration of different permafrost degradation landscapes and the employment of soil fractionation techniques is a useful combination to investigate soil development and SOM stabilization processes in this sensitive ecosystem.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 3","pages":"199 - 223"},"PeriodicalIF":3.9,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01132-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140096857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-08DOI: 10.1007/s10533-024-01124-4
Jonas Stage Sø, Kenneth Thorø Martinsen, Theis Kragh, Kaj Sand-Jensen
Ponds are regarded as greenhouse gas (GHG) emission hot spots, but how hot are they? We examined this question by measuring methane (CH4) and carbon dioxide (CO2) fluxes in six forest and open land ponds on grasslands in Denmark during summer and winter. We used floating chambers with do-it-yourself sensors and automated headspace venting, allowing for 7404 hourly measurements. We found highly variable gas fluxes within ponds and between seasons and pond types. Ebullitive CH4 fluxes were more variable than diffusive CH4 fluxes. Ebullition was absent when total CH4 fluxes were lowest (15 µmol m−2 h−1), dominant (> 90%) at the highest fluxes (> 400 µmol m−2 h−1), and increased with water temperature. In summer, a minor daily increase in diffusive fluxes was found on days with high wind speed, while CH4 ebullition remained constant. CO2 fluxes paralleled the day-night balance of photosynthesis and respiration. Mean CH4 ebullition in open and forest ponds exceeded CH4 diffusive fluxes 4.1 and 7.1-fold in summer (avg. 22.5 °C) and 2.3 and 2.5-fold in winter (9.6 °C), respectively. CO2 emissions were higher on a molar basis than CH4 emissions, both in summer and winter, while their annual global warming potentials were similar. Mean annual gas emissions from open and forest ponds (1092 and 2527 g CO2e m−2 y−1) are naturally high due to extensive external input of dissolved CO2 and organic carbon relative to pond area and volume.
{"title":"Hourly methane and carbon dioxide fluxes from temperate ponds","authors":"Jonas Stage Sø, Kenneth Thorø Martinsen, Theis Kragh, Kaj Sand-Jensen","doi":"10.1007/s10533-024-01124-4","DOIUrl":"10.1007/s10533-024-01124-4","url":null,"abstract":"<div><p>Ponds are regarded as greenhouse gas (GHG) emission hot spots, but how hot are they? We examined this question by measuring methane (CH<sub>4</sub>) and carbon dioxide (CO<sub>2</sub>) fluxes in six forest and open land ponds on grasslands in Denmark during summer and winter. We used floating chambers with do-it-yourself sensors and automated headspace venting, allowing for 7404 hourly measurements. We found highly variable gas fluxes within ponds and between seasons and pond types. Ebullitive CH<sub>4</sub> fluxes were more variable than diffusive CH<sub>4</sub> fluxes. Ebullition was absent when total CH<sub>4</sub> fluxes were lowest (15 µmol m<sup>−2</sup> h<sup>−1</sup>), dominant (> 90%) at the highest fluxes (> 400 µmol m<sup>−2</sup> h<sup>−1</sup>), and increased with water temperature. In summer, a minor daily increase in diffusive fluxes was found on days with high wind speed, while CH<sub>4</sub> ebullition remained constant. CO<sub>2</sub> fluxes paralleled the day-night balance of photosynthesis and respiration. Mean CH<sub>4</sub> ebullition in open and forest ponds exceeded CH<sub>4</sub> diffusive fluxes 4.1 and 7.1-fold in summer (avg. 22.5 °C) and 2.3 and 2.5-fold in winter (9.6 °C), respectively. CO<sub>2</sub> emissions were higher on a molar basis than CH<sub>4</sub> emissions, both in summer and winter, while their annual global warming potentials were similar. Mean annual gas emissions from open and forest ponds (1092 and 2527 g CO<sub>2</sub>e m<sup>−2</sup> y<sup>−1</sup>) are naturally high due to extensive external input of dissolved CO<sub>2</sub> and organic carbon relative to pond area and volume.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 2","pages":"177 - 195"},"PeriodicalIF":3.9,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01124-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140067754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-06DOI: 10.1007/s10533-024-01126-2
L. M. Gillespie, P. Kolari, L. Kulmala, S. M. Leitner, M. Pihlatie, S. Zechmeister-Boltenstern, E. Díaz-Pinés
Changing water regimes (e.g. drought) have unknown long-term consequences on the stability and resilience of soil microorganisms who determine much of the carbon and nitrogen exchange between the biosphere and atmosphere. Shifts in their activity could feedback into ongoing climate change. In this study, we explored soil drought effects on soil greenhouse gas (GHG; CO2, CH4, N2O) fluxes over time in two sites: a boreal, coniferous forest in Finland (Hyytiälä) and a temperate, broadleaf forest in Austria (Rosalia). Topsoil moisture and topsoil temperature data were used to identify soil drought events, defined as when soil moisture is below the soil moisture at the permanent wilting point. Data over multiple years from automated GHG flux chambers installed on the forest floor were then analyzed using generalized additive models (GAM) to study whether GHG fluxes differed before and after drought events and whether there was an overall, multiyear temporal trend. Results showed CO2 and N2O emissions to be more affected by drought and long-term trends at Hyytiälä with increased CO2 emission and decreased N2O emissions both following drought and over the entire measurement period. CH4 uptake increased at both sites both during non-drought periods and as an overall, multiyear trend and was predominantly affected by soil moisture dynamics. Multiyear trends also suggest an increase in soil temperature in the boreal forest and a decrease in soil moisture in the temperate forest. These findings underline forests as an important sink for CH4, possibly with an increasing rate in a future climate.
{"title":"Drought effects on soil greenhouse gas fluxes in a boreal and a temperate forest","authors":"L. M. Gillespie, P. Kolari, L. Kulmala, S. M. Leitner, M. Pihlatie, S. Zechmeister-Boltenstern, E. Díaz-Pinés","doi":"10.1007/s10533-024-01126-2","DOIUrl":"10.1007/s10533-024-01126-2","url":null,"abstract":"<div><p>Changing water regimes (e.g. drought) have unknown long-term consequences on the stability and resilience of soil microorganisms who determine much of the carbon and nitrogen exchange between the biosphere and atmosphere. Shifts in their activity could feedback into ongoing climate change. In this study, we explored soil drought effects on soil greenhouse gas (GHG; CO<sub>2</sub>, CH<sub>4</sub>, N<sub>2</sub>O) fluxes over time in two sites: a boreal, coniferous forest in Finland (Hyytiälä) and a temperate, broadleaf forest in Austria (Rosalia). Topsoil moisture and topsoil temperature data were used to identify soil drought events, defined as when soil moisture is below the soil moisture at the permanent wilting point. Data over multiple years from automated GHG flux chambers installed on the forest floor were then analyzed using generalized additive models (GAM) to study whether GHG fluxes differed before and after drought events and whether there was an overall, multiyear temporal trend. Results showed CO<sub>2</sub> and N<sub>2</sub>O emissions to be more affected by drought and long-term trends at Hyytiälä with increased CO<sub>2</sub> emission and decreased N<sub>2</sub>O emissions both following drought and over the entire measurement period. CH<sub>4</sub> uptake increased at both sites both during non-drought periods and as an overall, multiyear trend and was predominantly affected by soil moisture dynamics. Multiyear trends also suggest an increase in soil temperature in the boreal forest and a decrease in soil moisture in the temperate forest. These findings underline forests as an important sink for CH<sub>4</sub>, possibly with an increasing rate in a future climate.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 2","pages":"155 - 175"},"PeriodicalIF":3.9,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01126-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140043400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-02DOI: 10.1007/s10533-024-01127-1
Stanisław Kurowski, Katarzyna Łukawska-Matuszewska, Anđela Čović, Dražan Jozić, Aleksandra Brodecka-Goluch
Pockmarks are formed as a result of gas (methane) or/and groundwater outflow from the sea bottom. Methane, the second most important (after CO2) greenhouse gas, has a significant impact on biogeochemical processes in the bottom sediments by affecting the cycling of some elements, e.g. C, Fe, and S. Active pockmarks may also lead to changes in water column conditions by causing nutrients release from sediments. In the present study, we have focused on the impact of biogeochemical processes in pockmarks (methanogenesis, anaerobic methane oxidation, and groundwater seepage) on the transformation of iron (Fe) and the mineral composition of the sediment. In pore water, concentrations of hydrogen sulfide, phosphate, ammonia, sulfate, chloride, dissolved inorganic carbon, iron, and methane were analyzed. In the sediment, Fe speciation was performed using sequential extraction. The mineral composition was determined using powder X-Ray diffraction and scanning electron microscopy. The results from two pockmarks (with active gas seepage and groundwater infiltration) and two reference stations in the southern Baltic Sea show that geochemical conditions in pockmark sediments are significantly different from those in the typical muddy sea bottom. Pore water in pockmarks is characterized by lower sulfate and higher dissolved carbon concentrations as compared to areas of the seafloor where such structures are absent. This is due to the outflow of groundwater, which was confirmed by lower chloride concentration. In addition, sulfate is used to oxidize methane diffusing from deeper layers. Sediments in pockmarks are enriched in Fe(II) carbonates and depleted in Fe(III) (oxy)hydroxides, resulting from the anaerobic oxidation of methane with Fe(III) (Fe-AOM). Ferrous iron produced in large quantities during Fe-AOM is precipitated with carbonates.
地幔是海底气体(甲烷)或/和地下水外流形成的。甲烷是仅次于二氧化碳的第二大温室气体,通过影响某些元素(如碳、铁和硒)的循环,对海底沉积物中的生物地球化学过程产生重大影响。在本研究中,我们重点研究了麻子痕中的生物地球化学过程(甲烷生成、厌氧甲烷氧化和地下水渗流)对铁(Fe)转化和沉积物矿物组成的影响。在孔隙水中,分析了硫化氢、磷酸盐、氨、硫酸盐、氯化物、溶解无机碳、铁和甲烷的浓度。在沉积物中,采用顺序萃取法对铁进行了标样。使用粉末 X 射线衍射和扫描电子显微镜确定了矿物成分。波罗的海南部两个麻子地(有活跃的气体渗流和地下水渗透)和两个参照站的研究结果表明,麻子地沉积物的地球化学条件与典型的泥质海底沉积物有很大不同。与没有此类结构的海底区域相比,麻子痕孔隙水的硫酸盐浓度较低,溶解碳浓度较高。这是因为有地下水流出,较低的氯化物浓度证实了这一点。此外,硫酸盐被用来氧化从深层扩散的甲烷。麻坑中的沉积物富含铁(II)碳酸盐,而铁(III)(氧)氢氧化物则很少,这是甲烷与铁(III)进行厌氧氧化(Fe-AOM)的结果。Fe-AOM过程中产生的大量亚铁与碳酸盐沉淀在一起。
{"title":"Effects of pockmark activity on iron cycling and mineral composition in continental shelf sediments (southern Baltic Sea)","authors":"Stanisław Kurowski, Katarzyna Łukawska-Matuszewska, Anđela Čović, Dražan Jozić, Aleksandra Brodecka-Goluch","doi":"10.1007/s10533-024-01127-1","DOIUrl":"10.1007/s10533-024-01127-1","url":null,"abstract":"<div><p>Pockmarks are formed as a result of gas (methane) or/and groundwater outflow from the sea bottom. Methane, the second most important (after CO<sub>2</sub>) greenhouse gas, has a significant impact on biogeochemical processes in the bottom sediments by affecting the cycling of some elements, e.g. C, Fe, and S. Active pockmarks may also lead to changes in water column conditions by causing nutrients release from sediments. In the present study, we have focused on the impact of biogeochemical processes in pockmarks (methanogenesis, anaerobic methane oxidation, and groundwater seepage) on the transformation of iron (Fe) and the mineral composition of the sediment. In pore water, concentrations of hydrogen sulfide, phosphate, ammonia, sulfate, chloride, dissolved inorganic carbon, iron, and methane were analyzed. In the sediment, Fe speciation was performed using sequential extraction. The mineral composition was determined using powder X-Ray diffraction and scanning electron microscopy. The results from two pockmarks (with active gas seepage and groundwater infiltration) and two reference stations in the southern Baltic Sea show that geochemical conditions in pockmark sediments are significantly different from those in the typical muddy sea bottom. Pore water in pockmarks is characterized by lower sulfate and higher dissolved carbon concentrations as compared to areas of the seafloor where such structures are absent. This is due to the outflow of groundwater, which was confirmed by lower chloride concentration. In addition, sulfate is used to oxidize methane diffusing from deeper layers. Sediments in pockmarks are enriched in Fe(II) carbonates and depleted in Fe(III) (oxy)hydroxides, resulting from the anaerobic oxidation of methane with Fe(III) (Fe-AOM). Ferrous iron produced in large quantities during Fe-AOM is precipitated with carbonates.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"167 2","pages":"135 - 154"},"PeriodicalIF":3.9,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-024-01127-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140016576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}