Andrea Walters, Dorothée Kopp, Pierre Cresson, Marianne Robert
Understanding how energy is transferred within and across ecosystems is essential to better understand drivers and future consequences of shifts in energy pathways. We used stable isotope ratios of 1932 fish individuals belonging to the 11 most abundant fish species collected across 300,000 km2 along the English Channel–Celtic Sea continuum. To examine cross‐ecosystem differences in trophic functioning, we assessed the effects of both extrinsic (depth) and intrinsic factors (body size and feeding guild) on resource use and trophic position of fish consumers. Positive relationships between trophic position and body size were observed for zoobenthivore and piscivore fishes, whereas the relationship was negative for benthivore fishes. Body size is thus an important structuring mechanism in the systems. Trophic position decreased with increasing depth for all levels of biological organization. The amplitude of the change between shallow and deep stations was equivalent to more than one trophic level for generalist planktivores and piscivores. In the shallow English Channel, the food web is marked by stronger coupling of benthic and pelagic habitats via diverse pathways, due to the proximity of benthic and pelagic species, whereas in the Celtic Sea, increasing depth leads to a decoupling of benthic and pelagic pathways. For piscivores, a consistent pattern of increasing dependence on benthic subsidies with increasing size and depth highlights the importance of large consumers coupling energy across food web compartments. This study describes the relationship between production and trophic functioning and provides an empirical ecological explanation for cross‐ecosystem differences in observed trophic structures.
{"title":"Cross‐ecosystem trophic structure and benthic–pelagic coupling: Effects of depth, body size, and feeding guild","authors":"Andrea Walters, Dorothée Kopp, Pierre Cresson, Marianne Robert","doi":"10.1002/lno.12794","DOIUrl":"https://doi.org/10.1002/lno.12794","url":null,"abstract":"Understanding how energy is transferred within and across ecosystems is essential to better understand drivers and future consequences of shifts in energy pathways. We used stable isotope ratios of 1932 fish individuals belonging to the 11 most abundant fish species collected across 300,000 km<jats:sup>2</jats:sup> along the English Channel–Celtic Sea continuum. To examine cross‐ecosystem differences in trophic functioning, we assessed the effects of both extrinsic (depth) and intrinsic factors (body size and feeding guild) on resource use and trophic position of fish consumers. Positive relationships between trophic position and body size were observed for zoobenthivore and piscivore fishes, whereas the relationship was negative for benthivore fishes. Body size is thus an important structuring mechanism in the systems. Trophic position decreased with increasing depth for all levels of biological organization. The amplitude of the change between shallow and deep stations was equivalent to more than one trophic level for generalist planktivores and piscivores. In the shallow English Channel, the food web is marked by stronger coupling of benthic and pelagic habitats via diverse pathways, due to the proximity of benthic and pelagic species, whereas in the Celtic Sea, increasing depth leads to a decoupling of benthic and pelagic pathways. For piscivores, a consistent pattern of increasing dependence on benthic subsidies with increasing size and depth highlights the importance of large consumers coupling energy across food web compartments. This study describes the relationship between production and trophic functioning and provides an empirical ecological explanation for cross‐ecosystem differences in observed trophic structures.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"44 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989002","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}
Ignacio Granados, Manuel Toro, Carlos Montes, Antonio Camacho
We present a detailed observational study of the effects of the impulse wave caused by a snow‐avalanche on an alpine lake (Lake Peñalara, Sierra de Guadarrama, Spain). The avalanche broke the lake's ice cover (> 50 cm thick) and caused the lake to overflow. The impulse wave altered the lake water column stratification and physicochemical properties (dissolved oxygen, conductivity) in the short (hours) and mid‐term (days and weeks). It also caused the mobilization of hundreds of cubic meters of sediment, changing the lake morphometry. The sediment reconfiguration is likely the cause of the observed increased sedimentation rate and changes in the zooplankton density and composition in the following 4 yr after the avalanche, including the resurrection of a cladoceran species (Daphnia pulicaria) that had disappeared from the lake decades ago. Events such as the one we present can have significant paleolimnological implications: in this case, 75 cm of the sediment sequence were lost. Given these results, we propose that past avalanches could be the explanation to the almost complete removal of sediment from the deepest part of the lake around 260 yr cal BCE.
{"title":"Snow avalanche‐induced disturbances can resurrect extinct zooplankton and alter paleolimnological records","authors":"Ignacio Granados, Manuel Toro, Carlos Montes, Antonio Camacho","doi":"10.1002/lno.12783","DOIUrl":"https://doi.org/10.1002/lno.12783","url":null,"abstract":"We present a detailed observational study of the effects of the impulse wave caused by a snow‐avalanche on an alpine lake (Lake Peñalara, Sierra de Guadarrama, Spain). The avalanche broke the lake's ice cover (> 50 cm thick) and caused the lake to overflow. The impulse wave altered the lake water column stratification and physicochemical properties (dissolved oxygen, conductivity) in the short (hours) and mid‐term (days and weeks). It also caused the mobilization of hundreds of cubic meters of sediment, changing the lake morphometry. The sediment reconfiguration is likely the cause of the observed increased sedimentation rate and changes in the zooplankton density and composition in the following 4 yr after the avalanche, including the resurrection of a cladoceran species (<jats:italic>Daphnia pulicaria</jats:italic>) that had disappeared from the lake decades ago. Events such as the one we present can have significant paleolimnological implications: in this case, 75 cm of the sediment sequence were lost. Given these results, we propose that past avalanches could be the explanation to the almost complete removal of sediment from the deepest part of the lake around 260 yr cal BCE.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"37 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142989000","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}
Daniela Y. Gaurisas, Daniëlle S. W. de Jonge, Fernanda M. M. Alves, Alycia J. Smith, Andrew K. Sweetman, Angelo F. Bernardino
Abyssal ecosystems comprise more than 50% of the Earth's area and constitute an important reservoir in the global carbon cycle. With ocean productivity expected to decrease due to global warming, these ecosystems could face significant impacts in the coming decades. Benthic macrofauna are a key component of the seafloor carbon and nitrogen cycles, but limited in situ measurements result in high global uncertainty on the rates of metazoan C assimilation at abyssal depths. We sampled the macrofaunal community at the Cabo Verde Abyssal Basin (CVAB), finding a higher abundance of macrofaunal organisms (polychaetes and crustaceans) compared to other abyssal basins of the Atlantic Ocean. We assessed their short‐term response to a simulated phytodetrital pulse during a two‐day tracer in situ experiment at 4200 m depth. 13C and 15N‐labeled diatoms were used as a food source, and the uptake of these elements by the macrofaunal community was quantified. Results showed that surface deposit feeding polychaetes contributed the most to the biomass (75%) and C and N uptake (70% and 83%), revealing their importance to organic matter cycling in the abyss. Enrichment was modest in most macrofauna; however, the uptake of labeled diatoms by some organisms was detected after 48 h. Our findings suggest that CVAB might receive more pelagic input than other abyssal basins underlying oligotrophic regimes. This study establishes a baseline for both macrofauna characterization and benthic ecosystem functioning in abyssal sediments around Cabo Verde and underscores the crucial role of macrofaunal‐sized benthic organisms in C uptake and assimilation within the tropical abyssal Atlantic.
{"title":"Short‐term response of an abyssal macrofaunal community to a simulated phytodetrital pulse in the Cabo Verde Abyssal Basin, Northeast Tropical Atlantic Ocean","authors":"Daniela Y. Gaurisas, Daniëlle S. W. de Jonge, Fernanda M. M. Alves, Alycia J. Smith, Andrew K. Sweetman, Angelo F. Bernardino","doi":"10.1002/lno.12775","DOIUrl":"https://doi.org/10.1002/lno.12775","url":null,"abstract":"Abyssal ecosystems comprise more than 50% of the Earth's area and constitute an important reservoir in the global carbon cycle. With ocean productivity expected to decrease due to global warming, these ecosystems could face significant impacts in the coming decades. Benthic macrofauna are a key component of the seafloor carbon and nitrogen cycles, but limited <jats:italic>in situ</jats:italic> measurements result in high global uncertainty on the rates of metazoan C assimilation at abyssal depths. We sampled the macrofaunal community at the Cabo Verde Abyssal Basin (CVAB), finding a higher abundance of macrofaunal organisms (polychaetes and crustaceans) compared to other abyssal basins of the Atlantic Ocean. We assessed their short‐term response to a simulated phytodetrital pulse during a two‐day tracer <jats:italic>in situ</jats:italic> experiment at 4200 m depth. <jats:sup>13</jats:sup>C and <jats:sup>15</jats:sup>N‐labeled diatoms were used as a food source, and the uptake of these elements by the macrofaunal community was quantified. Results showed that surface deposit feeding polychaetes contributed the most to the biomass (75%) and C and N uptake (70% and 83%), revealing their importance to organic matter cycling in the abyss. Enrichment was modest in most macrofauna; however, the uptake of labeled diatoms by some organisms was detected after 48 h. Our findings suggest that CVAB might receive more pelagic input than other abyssal basins underlying oligotrophic regimes. This study establishes a baseline for both macrofauna characterization and benthic ecosystem functioning in abyssal sediments around Cabo Verde and underscores the crucial role of macrofaunal‐sized benthic organisms in C uptake and assimilation within the tropical abyssal Atlantic.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"51 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142975189","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}
Circulation model of Lake Issyk‐Kul is compiled based on Princeton Ocean Model with real bathymetry and atmospheric and river runoff forcings. According to the model, the cyclonic circulation develops in the lake from May to January, when a seasonal thermocline is present, while in February through April it vanishes or changes for a weak anticyclonic circulation. Wind‐driven coastal jets and internal Kelvin waves intensify vertical mixing at a lateral periphery of the lake over sloping bottom. Due to enhanced vertical mixing and reduced depth, the water column warms up and cools down faster at the lateral periphery of the lake than in the deep central part. This, in view of geostrophic balance, causes cyclonic circulation in the period from late spring to early winter and the anticyclonic circulation during the rest of the year. River runoff does not play a primary role and only moderately contributes to the cyclonic circulation through the geostrophic adjustment of buoyant coastal discharges to the lake whose salinity is about 6 ppt. At the end of winter and beginning of spring, when river runoff is minimal, it is nevertheless capable of maintaining weak hydrostatically stable stratification in the coastal zone and thereby significantly weakening the development of cascading and deep‐water ventilation. Model simulations showed that the cyclonic circulation prevailing in Lake Issyk‐Kul would develop even without positive wind stress curl attributed to local winds.
{"title":"Generation of cyclonic gyre in large saline lake through differential warming","authors":"Maria Golenko, Victor Zhurbas, Peter Zavialov","doi":"10.1002/lno.12774","DOIUrl":"https://doi.org/10.1002/lno.12774","url":null,"abstract":"Circulation model of Lake Issyk‐Kul is compiled based on Princeton Ocean Model with real bathymetry and atmospheric and river runoff forcings. According to the model, the cyclonic circulation develops in the lake from May to January, when a seasonal thermocline is present, while in February through April it vanishes or changes for a weak anticyclonic circulation. Wind‐driven coastal jets and internal Kelvin waves intensify vertical mixing at a lateral periphery of the lake over sloping bottom. Due to enhanced vertical mixing and reduced depth, the water column warms up and cools down faster at the lateral periphery of the lake than in the deep central part. This, in view of geostrophic balance, causes cyclonic circulation in the period from late spring to early winter and the anticyclonic circulation during the rest of the year. River runoff does not play a primary role and only moderately contributes to the cyclonic circulation through the geostrophic adjustment of buoyant coastal discharges to the lake whose salinity is about 6 ppt. At the end of winter and beginning of spring, when river runoff is minimal, it is nevertheless capable of maintaining weak hydrostatically stable stratification in the coastal zone and thereby significantly weakening the development of cascading and deep‐water ventilation. Model simulations showed that the cyclonic circulation prevailing in Lake Issyk‐Kul would develop even without positive wind stress curl attributed to local winds.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"6 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142974533","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}
Owen F. Rowe, Joanna Paczkowska, Andreas Brutemark, Sonia Brugel, Sachia J. Traving, Robert Lefébure, Fernanda Miranda, Liudmyla Guleikova, Evelina Griniene, Iveta Jurgensone, Pär Byström, Lasse Riemann, Agneta Andersson
Climate change is projected to cause elevated precipitation in northern Europe, leading to increased runoff of terrestrial matter to coastal areas. The consequences for food web production and ecosystem function remain unclear. A mesocosm experiment was performed to investigate the impacts of elevated terrestrial matter input, using a natural plankton community from the northern Baltic Sea with added young‐of‐the‐year perch as planktivorous top consumer. Addition of terrestrial matter caused water browning and increased dissolved organic carbon and inorganic nutrient concentrations. Phytoplankton primary production showed a negative response to terrestrial matter due to decreased light availability, while heterotrophic bacterial production increased. The trophic balance, calculated as the difference between primary production and heterotrophic bacterial production, indicated that net‐heterotrophy was triggered by terrestrial matter enrichment. Primary production was identified as the main basal energy source for fish. Addition of terrestrial matter reduced the food web efficiency, calculated as the ratio between fish production and basal production (primary production + heterotrophic bacterial production). Furthermore, stable isotope analysis of seston and fish indicated that the added terrestrial matter was not efficiently incorporated in the food web and only marginally altered the food web trophic positions. The results suggest that the main food chain consisted of phytoplankton, mesozooplankton, and fish, and that the ecosystem production was overall light driven. Under a changing climate, several negative effects can be expected, including a poorer light climate, reduced ecosystem production and net‐heterotrophy. These alterations have potentially significant consequences for ecosystem functioning, fish production, and thus ecosystem services.
{"title":"Climate change–induced terrestrial matter runoff may decrease food web production in coastal ecosystems","authors":"Owen F. Rowe, Joanna Paczkowska, Andreas Brutemark, Sonia Brugel, Sachia J. Traving, Robert Lefébure, Fernanda Miranda, Liudmyla Guleikova, Evelina Griniene, Iveta Jurgensone, Pär Byström, Lasse Riemann, Agneta Andersson","doi":"10.1002/lno.12762","DOIUrl":"https://doi.org/10.1002/lno.12762","url":null,"abstract":"Climate change is projected to cause elevated precipitation in northern Europe, leading to increased runoff of terrestrial matter to coastal areas. The consequences for food web production and ecosystem function remain unclear. A mesocosm experiment was performed to investigate the impacts of elevated terrestrial matter input, using a natural plankton community from the northern Baltic Sea with added young‐of‐the‐year perch as planktivorous top consumer. Addition of terrestrial matter caused water browning and increased dissolved organic carbon and inorganic nutrient concentrations. Phytoplankton primary production showed a negative response to terrestrial matter due to decreased light availability, while heterotrophic bacterial production increased. The trophic balance, calculated as the difference between primary production and heterotrophic bacterial production, indicated that net‐heterotrophy was triggered by terrestrial matter enrichment. Primary production was identified as the main basal energy source for fish. Addition of terrestrial matter reduced the food web efficiency, calculated as the ratio between fish production and basal production (primary production + heterotrophic bacterial production). Furthermore, stable isotope analysis of seston and fish indicated that the added terrestrial matter was not efficiently incorporated in the food web and only marginally altered the food web trophic positions. The results suggest that the main food chain consisted of phytoplankton, mesozooplankton, and fish, and that the ecosystem production was overall light driven. Under a changing climate, several negative effects can be expected, including a poorer light climate, reduced ecosystem production and net‐heterotrophy. These alterations have potentially significant consequences for ecosystem functioning, fish production, and thus ecosystem services.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"6 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142961529","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}
Rudi Schuech, Lasse Tor Nielsen, Stuart Humphries, Dave Smith, Thomas Kiørboe
Flagella are crucial to the interactions of unicellular organisms with their surrounding aquatic environment. One ecologically important group of flagellates, the dinoflagellates, has a unique flagellar arrangement consisting of a trailing and a transversal flagellum. The latter is recessed within a groove around the cell and drives a hair‐bearing membrane that undulates with a helical beat. Dinoflagellates are further unique by having clearance rates that are an order of magnitude higher than those of other similarly sized phagotrophic flagellates, overlapping in size and swimming speed with ciliates. Here, using flow visualization and computational fluid dynamics, we show how this arrangement of just two flagella propels these large cells at high speeds and allows very high clearance rates. We find that the transverse flagellum provides most of the forward thrust, whereas the trailing flagellum is mainly for steering. The flagellar hairs and the sheet‐like structure of the transverse flagellum allow dinoflagellates to exert strong propulsive forces at high efficiency without extending a long flagellum far into the surrounding fluid. The unique flagellar arrangement of dinoflagellates may therefore be key to their evolutionary success.
{"title":"Fluid dynamics of dinoflagellate feeding and swimming","authors":"Rudi Schuech, Lasse Tor Nielsen, Stuart Humphries, Dave Smith, Thomas Kiørboe","doi":"10.1002/lno.12764","DOIUrl":"https://doi.org/10.1002/lno.12764","url":null,"abstract":"Flagella are crucial to the interactions of unicellular organisms with their surrounding aquatic environment. One ecologically important group of flagellates, the dinoflagellates, has a unique flagellar arrangement consisting of a trailing and a transversal flagellum. The latter is recessed within a groove around the cell and drives a hair‐bearing membrane that undulates with a helical beat. Dinoflagellates are further unique by having clearance rates that are an order of magnitude higher than those of other similarly sized phagotrophic flagellates, overlapping in size and swimming speed with ciliates. Here, using flow visualization and computational fluid dynamics, we show how this arrangement of just two flagella propels these large cells at high speeds and allows very high clearance rates. We find that the transverse flagellum provides most of the forward thrust, whereas the trailing flagellum is mainly for steering. The flagellar hairs and the sheet‐like structure of the transverse flagellum allow dinoflagellates to exert strong propulsive forces at high efficiency without extending a long flagellum far into the surrounding fluid. The unique flagellar arrangement of dinoflagellates may therefore be key to their evolutionary success.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"14 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142924977","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}
In high‐mountain landscapes, organic carbon (OC) is often limited and heterogeneously stored in poorly developed soils, snow, ground ice, and glaciers. Climate change influences the dynamics of OC mobilization to—and processing into—the recipient streams. Dynamics vary from seasonal (e.g., snow melt in spring) to daily (e.g., ice melt in summer) depending on the location of the streams within the catchment. Capturing the temporal richness of stream biogeochemical signals has become a reality with the advent of high‐resolution sensors. In this study, we applied wavelet analysis to high‐frequency discharge (Q) and dissolved organic carbon (DOC) measurements from nine streams in the Swiss Alps to investigate the persistence of synchrony in Q (SQ) and DOC (SDOC) among streams, and their response to drainage network position, climate, and land cover gradients across different time scales. Our findings revealed that SQ and SDOC decayed non‐linearly over the first ~ 5 km and stabilized from this point onwards, indicating that localized controls influenced synchrony within single basins, but drivers operating at regional scale acted as synchrony stabilizers. We also showed that short‐term (0–10 d) SQ and SDOC were strongly influenced by the distance between streams and network connectivity. In contrast, catchment‐related properties (i.e., altitude or land cover) were more important drivers of SQ and SDOC dynamics at longer time scales (> 50 d). However, the degree to which local catchment properties controlled synchrony patterns at the longest timescales depended both on response variables (i.e., Q vs. DOC) and land cover (i.e., vegetation vs. glacier). Elucidating the most prominent timescales of SDOC is relevant given the hydrological alterations projected for high‐mountain regions. We show that glaciers impose a unique seasonal regime on DOC concentration, potentially overriding the effects of other local hydrological or biogeochemical processes during downstream transport. Consequently, SDOC dynamics in high‐mountain streams may change as glaciers shrink, thereby altering downstream opportunities for biogeochemical transformations.
在高山景观中，有机碳（OC）通常是有限的，并且不均匀地储存在发育不良的土壤、雪、地面冰和冰川中。气候变化影响OC向接收流的动员和向接收流的加工动态。动态变化从季节性（如春季融雪）到每日（如夏季融冰）不等，这取决于集水区内溪流的位置。随着高分辨率传感器的出现，捕获河流生物地球化学信号的时间丰富性已经成为现实。本研究利用小波分析方法对瑞士阿尔卑斯地区9条河流的高频排放(Q)和溶解有机碳（DOC）数据进行分析，探讨了河流之间Q （SQ）和DOC （SDOC）同步的持久性，以及它们在不同时间尺度上对排水网络位置、气候和土地覆盖梯度的响应。研究结果表明，SQ和SDOC在前5 km呈非线性衰减，此后趋于稳定，表明局部控制因素影响了单个盆地的同步，但区域尺度上的驱动因素起着同步稳定器的作用。我们还发现，短期（0-10 d） SQ和SDOC受到流之间距离和网络连接的强烈影响。相比之下，流域相关属性（即海拔或土地覆盖）在更长的时间尺度上是SQ和SDOC动态的更重要驱动因素(>；然而，在最长时间尺度上，局部流域特性对同步模式的控制程度既取决于响应变量（即Q vs. DOC），也取决于土地覆盖（即植被vs.冰川）。考虑到预估的高山地区水文变化，阐明SDOC最突出的时间尺度是相关的。研究表明，冰川对DOC浓度施加了独特的季节性影响，可能会在下游运输过程中压倒其他当地水文或生物地球化学过程的影响。因此，高山溪流的SDOC动态可能随着冰川的萎缩而改变，从而改变下游生物地球化学转化的机会。
{"title":"Synchrony dynamics of dissolved organic carbon in high‐mountain streams: Insights into scale‐dependent processes","authors":"Lluís Gómez‐Gener, Nicola Deluigi, Tom J. Battin","doi":"10.1002/lno.12768","DOIUrl":"https://doi.org/10.1002/lno.12768","url":null,"abstract":"In high‐mountain landscapes, organic carbon (OC) is often limited and heterogeneously stored in poorly developed soils, snow, ground ice, and glaciers. Climate change influences the dynamics of OC mobilization to—and processing into—the recipient streams. Dynamics vary from seasonal (e.g., snow melt in spring) to daily (e.g., ice melt in summer) depending on the location of the streams within the catchment. Capturing the temporal richness of stream biogeochemical signals has become a reality with the advent of high‐resolution sensors. In this study, we applied wavelet analysis to high‐frequency discharge (<jats:italic>Q</jats:italic>) and dissolved organic carbon (DOC) measurements from nine streams in the Swiss Alps to investigate the persistence of synchrony in <jats:italic>Q</jats:italic> (<jats:italic>S</jats:italic><jats:sub><jats:italic>Q</jats:italic></jats:sub>) and DOC (<jats:italic>S</jats:italic><jats:sub>DOC</jats:sub>) among streams, and their response to drainage network position, climate, and land cover gradients across different time scales. Our findings revealed that <jats:italic>S</jats:italic><jats:sub><jats:italic>Q</jats:italic></jats:sub> and S<jats:sub>DOC</jats:sub> decayed non‐linearly over the first ~ 5 km and stabilized from this point onwards, indicating that localized controls influenced synchrony within single basins, but drivers operating at regional scale acted as synchrony stabilizers. We also showed that short‐term (0–10 d) <jats:italic>S</jats:italic><jats:sub><jats:italic>Q</jats:italic></jats:sub> and <jats:italic>S</jats:italic><jats:sub>DOC</jats:sub> were strongly influenced by the distance between streams and network connectivity. In contrast, catchment‐related properties (i.e., altitude or land cover) were more important drivers of <jats:italic>S</jats:italic><jats:sub><jats:italic>Q</jats:italic></jats:sub> and <jats:italic>S</jats:italic><jats:sub>DOC</jats:sub> dynamics at longer time scales (> 50 d). However, the degree to which local catchment properties controlled synchrony patterns at the longest timescales depended both on response variables (i.e., <jats:italic>Q</jats:italic> vs. DOC) and land cover (i.e., vegetation vs. glacier). Elucidating the most prominent timescales of <jats:italic>S</jats:italic><jats:sub>DOC</jats:sub> is relevant given the hydrological alterations projected for high‐mountain regions. We show that glaciers impose a unique seasonal regime on DOC concentration, potentially overriding the effects of other local hydrological or biogeochemical processes during downstream transport. Consequently, <jats:italic>S</jats:italic><jats:sub>DOC</jats:sub> dynamics in high‐mountain streams may change as glaciers shrink, thereby altering downstream opportunities for biogeochemical transformations.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"1 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142924978","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}
{"title":"Issue Information & TOC","authors":"","doi":"10.1002/lno.12791","DOIUrl":"https://doi.org/10.1002/lno.12791","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"12 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142904783","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}
{"title":"Issue Information & Masthead","authors":"","doi":"10.1002/lno.12789","DOIUrl":"https://doi.org/10.1002/lno.12789","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"13 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142904785","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}
{"title":"Issue Information & Members","authors":"","doi":"10.1002/lno.12792","DOIUrl":"https://doi.org/10.1002/lno.12792","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"65 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142904786","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}
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