Limnology and Oceanography最新文献_第8页

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-24 DOI: 10.1002/lno.70144

引用次数: 0

Contrasting impacts of flooding and tropical cyclones on estuarine plume environments 洪水和热带气旋对河口烟羽环境的影响对比

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-23 DOI: 10.1002/lno.70152

Xiangqian Zhou, Philip Wallhead, Jianzhong Ge

{"title":"Contrasting impacts of flooding and tropical cyclones on estuarine plume environments","authors":"Xiangqian Zhou, Philip Wallhead, Jianzhong Ge","doi":"10.1002/lno.70152","DOIUrl":"10.1002/lno.70152","url":null,"abstract":"Plume environments in large river estuaries are particularly sensitive to extreme hydrological and atmospheric events, especially when these occur concurrently. In summer 2020, the Changjiang River experienced a severe fluvial flood lasting over 1.5 months, with a high peak discharge, while two tropical cyclones passed nearby. Observations demonstrated an unusual eastward extension of the low-salinity plume, accompanied by elevated surface chlorophyll concentrations. A coupled physical-biogeochemical model was used to identify key environmental changes during this period, and numerical experiments were conducted to quantify individual and compound effects. Floodwater persistently increased stratification and created sustained favorable light conditions for phytoplankton growth. In contrast, the passage of cyclones increased vertical mixing, weakened stratification, and reduced regional productivity. During the neap tide after the first cyclone passage, re-stratification and enhanced nutrient supply created favorable conditions for phytoplankton growth, consistent with the observed high chlorophyll concentration. Although tropical cyclone impacts largely counteracted those of the flood, the compound extreme event still exhibited overall positive effects on net primary production within the plume system. Heterogeneous responses and variable preconditions underscore the need for high-resolution, high-complexity, and flexible models to contextualize observations and enable accurate forecasting of future extreme events.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2540-2555"},"PeriodicalIF":3.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144684556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Further increasing nitrogen concentration does not enhance the denitrification and DNRA potentials in eutrophic reefs: Insights from the differences in benthic categories 进一步增加氮浓度不会增强富营养化珊瑚礁的反硝化和DNRA潜力：来自底栖动物类别差异的见解

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-23 DOI: 10.1002/lno.70139

Zhiming Ning, Zhijin Liu, Kefu Yu, Ronglin Xia, Wei Jiang, Bin Yang, Guodong Song

{"title":"Further increasing nitrogen concentration does not enhance the denitrification and DNRA potentials in eutrophic reefs: Insights from the differences in benthic categories","authors":"Zhiming Ning, Zhijin Liu, Kefu Yu, Ronglin Xia, Wei Jiang, Bin Yang, Guodong Song","doi":"10.1002/lno.70139","DOIUrl":"10.1002/lno.70139","url":null,"abstract":"Low nitrogen (N) availability is critical to coral health and resilience. Dissimilatory nitrate reduction processes, such as denitrification, anammox, and dissimilatory nitrate reduction to ammonium (DNRA), play a vital role in regulating seawater N content. Thus, quantifying the rates of these processes is essential for assessing the overall health and recovery potential of N-enriched coral reefs. However, the diversity and complexity of benthic categories in coral reefs severely limit our understanding of the overall nitrate reduction capacity of these ecosystems. To address this, we utilized the 15N isotope tracing technique to assess denitrification, anammox, and DNRA for various benthic categories, including live corals, turf algae, sediments, biogenic rock, and coral rubble in the coral reefs of Weizhou Island. Our findings indicate that, except for sediments, the denitrification potential (0.1–5.6 mmol N m−2 d−1) significantly exceeded that of DNRA (0.1–1.8 mmol N m−2 d−1), while anammox (0.01–0.10 mmol N m−2 d−1) was negligible. There was a significant difference in denitrification rate among benthic categories, with massive corals Galaxea fascicularis and biogenic rock exhibiting the highest rate. Extrapolated to the respective reef area, both live corals and biogenic rock contributed the most to the integrated rates of denitrification and DNRA (27–41%). However, no significant change in the rate was observed when the nitrate concentration increased from 10 to 20 μM. Consequently, it is crucial to strictly control N emissions in N-enriched reefs impacted by human activities, while also prioritizing the protection of benthic categories that significantly contribute to denitrification.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2525-2539"},"PeriodicalIF":3.7,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144693877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Interplay between saltmarsh carbon burial and lateral exchange in coastal wetlands: The role of biomorphodynamic feedback 盐沼碳埋藏与滨海湿地横向交换的相互作用：生物形态动力学反馈的作用

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-22 DOI: 10.1002/lno.70135

Yuhan Wang, Zeng Zhou, Junji Yuan, Aijun Wang, Huan Li, Luzhen Chen, Karin R. Bryan, Simon M. Mudd

{"title":"Interplay between saltmarsh carbon burial and lateral exchange in coastal wetlands: The role of biomorphodynamic feedback","authors":"Yuhan Wang, Zeng Zhou, Junji Yuan, Aijun Wang, Huan Li, Luzhen Chen, Karin R. Bryan, Simon M. Mudd","doi":"10.1002/lno.70135","DOIUrl":"10.1002/lno.70135","url":null,"abstract":"Understanding the carbon sequestration of saltmarshes and the role of biomorphodynamic feedback are essential for the protection, management, and adaptation to climate change of coastal blue carbon ecosystems. We developed a biomorphodynamic model that simultaneously considers carbon vertical burial and lateral exchange of soil organic carbon and validated this model against field measurements. This model was then used to examine carbon dynamics in saltmarshes and to explore the integrated effects of hydrodynamics, vegetation growth, sediment transport, and morphological change on carbon sequestration and spatial patterns. We find that taking lateral transport of sediment and carbon into account results in a greater spatial gradient of carbon burial compared to that of biomass, especially near the marsh edge. This enhanced gradient is reflected in our field data. Hydrodynamics enhance the spatial heterogeneity of marsh carbon burial and exchange by suspending sediment at the production-governed edge and transporting carbon into the marsh where it deposits. In our study case, the transport loss at the saltmarsh front accounted for 43% of carbon production inputs, while carbon burial was only 40%. The carbon sequestration capacity of saltmarshes critically depends on the hydrodynamic complexity of the fringing zone, which in some cases can shift the role of saltmarshes from carbon sinks to sources. Our modeling framework facilitates more accurate predictions of how carbon sequestration responds to changes in landscape morphology and hydrodynamics, providing valuable insights for conservation strategies aimed at maximizing the climate change mitigation benefits of blue carbon ecosystems.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2511-2524"},"PeriodicalIF":3.7,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144678173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Revisiting the silicon isotopic signal of sponge skeletons and its implications 重温海绵骨架硅同位素信号及其意义

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-21 DOI: 10.1002/lno.70138

Manuel Maldonado, Katharine R. Hendry

{"title":"Revisiting the silicon isotopic signal of sponge skeletons and its implications","authors":"Manuel Maldonado, Katharine R. Hendry","doi":"10.1002/lno.70138","DOIUrl":"10.1002/lno.70138","url":null,"abstract":"This study investigates the relationship between the silicon (Si) isotopic composition of sponge skeletal silica (δ30SibSi) and seawater characteristics in sponge habitats, specifically the concentration of dissolved silicic acid and its Si isotopic signature (δ30SidSi). Initially, these correlations were considered a promising calibration proxies for paleoceanographic reconstructions, but the incorporation of subsequent data points into the dataset over the past decade has highlighted complexities in how sponges fractionate silicon isotopes during silicification processes. We revisit the historical dataset, including a detailed examination of each datapoint to identify biases related to environmental, biological, and taxonomic factors. We also contribute new isotopic data obtained by multi-collector inductively coupled plasma mass spectrometer analysis, specifically targeting underrepresented low-silicic-acid environments. This revised dataset highlights that anomalies in the calibration, in particular species with fused skeletal frameworks, remain incongruous. We found that part of the problem is that the relationship between silicic acid concentration and δ30SibSi in the revised dataset of only Demospongiae follows a distinct, statistically robust, non-linear trend different from the weak, linear fit in Hexactinellida. Consequently, isotopic data from these two sponge classes should not be combined for calibration analysis, if possible. Yet, while the robust non-linear regression for only Demospongiae revitalizes the proxy, the relationship becomes asymptotic at silicic acid values above 200 μM, limiting its applicability to Cenozoic and Mesozoic conditions and excluding early Paleozoic scenarios with high concentrations of silicic acid. Practical recommendations for using and improving the proxy are discussed.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2480-2495"},"PeriodicalIF":3.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70138","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Chemical proxies of glacier-derived and marine organic matter reveal low mixing in summer-stratified Arctic fjords 冰川来源和海洋有机质的化学代用指标显示，夏季分层北极峡湾的混合程度较低

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-21 DOI: 10.1002/lno.70140

Fabian Moye, Jana K. Geuer, Claudia Burau, Mourad Harir, Philippe Schmitt-Kopplin, Boris P. Koch, Tilmann Harder, Jan Tebben

{"title":"Chemical proxies of glacier-derived and marine organic matter reveal low mixing in summer-stratified Arctic fjords","authors":"Fabian Moye, Jana K. Geuer, Claudia Burau, Mourad Harir, Philippe Schmitt-Kopplin, Boris P. Koch, Tilmann Harder, Jan Tebben","doi":"10.1002/lno.70140","DOIUrl":"10.1002/lno.70140","url":null,"abstract":"The rapid deglaciation of the Arctic increases the flux of terrestrial organic matter into the marine carbon cycle. The proportions, mixing, and turnover rates of organic matter from deglaciated terrestrial and glacial watershed sources are poorly understood in Arctic fjords. We characterized the mixing and flux of dissolved organic matter (DOM) in two Arctic fjords, Kongsfjorden and Scoresby Sund. DOM was sampled and analyzed along the natural mixing gradient from glacial meltwater to the marine waterbody to reveal chemical proxies for glacier-derived organic matter utilizing (ultra)high-resolution mass spectrometry of solid-phase extracted DOM. The molecular composition of DOM in Kongsfjorden was homogenous in elemental ratios of O/C, H/C, and N/C and aromaticity due to high mixing and low glacial run-off. In Scoresby Sund, a strong correlation between DOM composition and salinity was observed. The freshwater proportion of DOM was characterized by a low N/C ratio, unsaturated molecules, and a high terrestrial index. The surface stratification in Scoresby Sund prevented vertical mixing of glacier-derived and marine DOM with denser water masses. Glacial meltwater DOM in Scoresby Sund was similar to terrestrial DOM, suggesting either an unknown source of additional DOM or selective DOM removal processes. In summary, the high proportion of terrestrial DOM proxies suggests a strong imprint of deglaciation on the Arctic carbon cycle.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2496-2510"},"PeriodicalIF":3.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70140","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144669757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Heterotrophic dependence and bidirectional metabolite exchange dynamics in a temperate coral 温带珊瑚的异养依赖和双向代谢物交换动力学

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-19 DOI: 10.1002/lno.70141

Taylor R. Lindsay, Willow M. Dunster, Kelton W. McMahon, Carlos Prada

{"title":"Heterotrophic dependence and bidirectional metabolite exchange dynamics in a temperate coral","authors":"Taylor R. Lindsay, Willow M. Dunster, Kelton W. McMahon, Carlos Prada","doi":"10.1002/lno.70141","DOIUrl":"10.1002/lno.70141","url":null,"abstract":"In temperate ecosystems, where cold, turbid waters constrain symbiotic potential, corals have evolved facultative symbiosis, providing an opportunity to explore coral energetics in the face of global climate change. We conducted an in situ light exclusion experiment on the facultatively symbiotic temperate coral Astrangia poculata to explore the interactions among environmental variables and host-symbiont metabolism. Corals exhibited photophysiological plasticity and ecotype switching based on light environment. Symbiont density positively correlated with calice density, despite A. poculata's slow calcification rate. To quantify the trophic ecology of the host and symbionts, we conducted compound-specific stable isotope analysis of amino acids. Coral host essential amino acid carbon isotope fingerprints overlapped between ecotypes and among light treatments and were distinct from symbionts, indicating that photosynthetically derived metabolites were present but not translocated en masse from symbiont to host. Instead, coral hosts relied heavily on heterotrophic carbon sources. This is corroborated by high trophic positions of host (2.5 ± 0.1) and symbionts (2.4 ± 0.3), which were well above presumed “autotrophs,” and ΣV values greater than the nominal cut off for “microbially reworked organic matter” (> 1.5), indicating bidirectional metabolite exchange between host and symbionts. While light availability modulated photophysiology and morphology, trophic ecology was rigid across different light conditions and between symbiotic ecotypes. Our data suggest that A. poculata predominantly relies on heterotrophy and bidirectionally shares metabolites with their mixotrophic symbionts irrespective of light conditions, challenging the classic theory of metabolism and symbiosis in temperate corals.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2464-2479"},"PeriodicalIF":3.7,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70141","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Light–dark conditions drive variability in phosphorus and ammonium uptake by epilithic biofilms along the main stem of a Mediterranean river 明暗条件驱动沿地中海河流主干的附着生物膜对磷和铵的吸收变化

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-18 DOI: 10.1002/lno.70134

David Pineda-Morante, María Argudo, Anna M. Romaní, Helena Guasch, Eugènia Martí

{"title":"Light–dark conditions drive variability in phosphorus and ammonium uptake by epilithic biofilms along the main stem of a Mediterranean river","authors":"David Pineda-Morante, María Argudo, Anna M. Romaní, Helena Guasch, Eugènia Martí","doi":"10.1002/lno.70134","DOIUrl":"10.1002/lno.70134","url":null,"abstract":"Benthic biofilms on cobbles (i.e., epilithic biofilms) control the uptake of soluble reactive phosphorus (SRP) and ammonium (NH4+) in headwater streams. However, nutrient uptake by biofilms in higher-order rivers, particularly those affected by anthropogenic nutrient inputs and hydrological regulation, remains poorly understood. To address this gap, we examined the spatial and temporal variability of SRP and NH4+ uptake by epilithic biofilms, as well as their main drivers under light and dark conditions, along the main stem of a fifth-order human-regulated Mediterranean river. In situ light–dark incubations were conducted in open recirculating chambers at six sites across four dates, using dual nutrient additions to quantify gross uptake (U) of SRP and NH4+. Uptake of NH4+ was consistently higher than USRP across sites and dates, particularly under light conditions, with both nutrients showing rates similar to those reported in previous reach-scale studies. Uptake of SRP was consistent under light and dark conditions, with spatial and temporal variability contributing similarly to the explained variation in uptake. In contrast, UNH4 differed markedly between light and dark conditions and exhibited site-specific temporal patterns, suggesting a stronger dependence on photoautotrophic demand and greater influence on local environmental conditions. Finally, USRP was primarily associated with biofilm metabolic activity, while UNH4 was more strongly related to ambient nutrient concentrations. Overall, this study expands our understanding of spatial and temporal variability in biofilm nutrient uptake and highlights the importance of considering light availability to better understand the role of biofilms in P and N retention.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2431-2446"},"PeriodicalIF":3.7,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70134","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

How marine heatwaves are reshaping phytoplankton in the Northeast Pacific 海洋热浪如何重塑东北太平洋的浮游植物

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-18 DOI: 10.1002/lno.70137

Loïck Kléparski, Clare Ostle, Sonia D. Batten, Nicolas Djeghri, Claudine Hauri, Rémi Pagès, Suzanne Strom

引用次数: 0

Hydrological seasonality is a major driver of ecosystem metabolism in tropical nonwadeable rivers 水文季节性是热带不可涉水河流生态系统代谢的主要驱动因素

IF 3.7 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-14 DOI: 10.1002/lno.70132

María M. Castillo, Amber J. Ulseth, Aarón Jarquín-Sánchez, Arturo Álvarez-Merino, Krista A. Capps

{"title":"Hydrological seasonality is a major driver of ecosystem metabolism in tropical nonwadeable rivers","authors":"María M. Castillo, Amber J. Ulseth, Aarón Jarquín-Sánchez, Arturo Álvarez-Merino, Krista A. Capps","doi":"10.1002/lno.70132","DOIUrl":"10.1002/lno.70132","url":null,"abstract":"Studies of annual patterns of ecosystem metabolism in rivers have primarily been conducted in temperate ecosystems, and little is known about metabolic regimes of tropical rivers. We estimated ecosystem metabolism in four nonwadeable rivers in southern México that varied in size and the extent of human disturbance. The smaller rivers with limited human disturbance showed reduced gross primary production (GPP; 1.0 and 1.7 g O2 m−2 d−1), ecosystem respiration (ER; − 1.9 g O2 m−2 d−1), and net ecosystem production (NEP) approaching autotrophy (− 0. 8 and − 0.3 g O2 m−2 d−1) relative to rivers draining larger, more disturbed catchments (GPP, 1.2 and 2.7 g O2 m−2 d−1; ER, − 5.7 and − 6.9 g O2 m−2 d−1; NEP, − 3.8 and − 3.7 g O2 m−2 d−1). In all rivers, GPP and ER varied seasonally with discharge. The smaller rivers exhibited a distinct pattern of greater and sustained GPP during periods of low discharge, a seasonal metabolic regime we describe as “flow decline.” In general, process–discharge relationships exhibited thresholds, with an initial decline in GPP and ER, with increasing discharge and an increase in ER at higher flows. Relative to larger and more disturbed watersheds, smaller rivers showed a more constrained metabolic fingerprint. Annual NEP (− 1033 and − 641 g C m−2 yr−1) in the larger rivers was more negative than the global average, supporting evidence from other studies that tropical rivers are greater contributors to CO2 emissions than temperate ecosystems. Our study indicates that hydrological seasonality is a major driver of metabolism in tropical rivers.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 9","pages":"2417-2430"},"PeriodicalIF":3.7,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://aslopubs.onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70132","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144629769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0