Limnology and Oceanography最新文献

{"title":"Eutrophication‐induced dinoflagellate succession contributes to marine carbon sequestration through refractory dissolved organic matter accumulation","authors":"Fu‐Tao Fang, Zhuo‐Yi Zhu, Yuan‐Bi Yi, Ding He, Hong‐Yan Bao, En‐Ren Zhang, Cheng‐Xu Zhou","doi":"10.1002/lno.70097","DOIUrl":"https://doi.org/10.1002/lno.70097","url":null,"abstract":"The increasing eutrophication of coastal seas is causing a shift in the most important phytoplankton groups from diatoms to dinoflagellates, but its feedback to marine carbon cycling remains unclear. Here, we investigated the potential of the key coastal phytoplankton, the diatom <jats:italic>Skeletonema costatum</jats:italic>, and the dinoflagellate <jats:italic>Prorocentrum donghaiense</jats:italic>, for refractory dissolved organic carbon (DOC) accumulation over dark degradation incubations of 70 d. Our multi‐method approach showed that dinoflagellate detritus, rather than diatom detritus, significantly contributes to refractory DOC. This is evidenced by the fact that the detritus of dinoflagellates compared to that of diatoms (1) has a weaker transmittance in infrared spectrometry, indicating a lower content of labile organic substances (alcohol and amide groups); (2) has a higher release and/or transformation efficiency of particulate organic carbon to DOC (81% vs. 50%); (3) has a lower content of labile fraction, amino acid (8% vs. 17% carbon) and exhibits lower degradability of the DOC formed (23% vs. 30%); (4) has a lower content of labile compounds determined by Fourier transform ion cyclotron resonance mass spectrometry (maximum molecular lability boundary: 21% vs. 31%); and (5) has a higher proportion of refractory carboxylic‐rich alicyclic molecules (57% ± 0.5% vs. 51% ± 0.7%) over incubations. Our results emphasize that eutrophication‐triggered coastal dinoflagellate succession has a significant potential for positive feedback to carbon sequestration through the formation of refractory DOC.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"83 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153309","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":"Continental‐scale seston stoichiometry reveals fundamental constraints on the elemental composition of particles transported by streams","authors":"David W. P. Manning, Arial J. Shogren, Jonathan P. Benstead, Zacharie T. Loveless","doi":"10.1002/lno.70084","DOIUrl":"https://doi.org/10.1002/lno.70084","url":null,"abstract":"Suspended particulate matter, or seston, represents an understudied flux of carbon (C), nitrogen (N), and phosphorus (P) in river networks. Here, we summarize riverine seston C : N : P stoichiometry data from 27 streams and rivers sampled regularly from 2014 to 2022 across the United States by the National Ecological Observatory Network (NEON). We examine relationships among seston C, N, and P content using standardized major‐axis (SMA) and ordinary least squares slopes to test congruence with a constant‐ratio model (scaling coefficient = 1), and hierarchical models to identify watershed‐level covariates of seston C : nutrient stoichiometric allometry. At the continental scale, C and N were tightly coupled and conformed to the constant‐ratio model, while seston C : P and N : P indicated weaker coupling and inconstant ratios across the range of C vs. P and N vs. P values. At the stream‐site scale, C : N, C : P, and N : P often exhibited slopes &lt; 1, indicating that within individual streams seston becomes more nutrient‐rich as seston concentration increases. Watershed forest cover, season, and discharge helped explain stoichiometric allometry across streams, where forested sites in wetter climates had lower scaling slopes, and slopes decreased with low flows. Our study underscores the importance of suspended particles as a material flux in river networks and highlights the interplay between biotic and abiotic factors that drive the relative consistency of its C : nutrient stoichiometry during transport from local to continental scales.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"17 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153310","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":"Vertical microbial fluxes in a modern permanently redox‐stratified lake provide insights into organic carbon sequestration and benthic–pelagic coupling during the Proterozoic Eon","authors":"Ashley B. Cohen, Vanja Klepac‐Ceraj, Kristen Bidas, Felix Weber, Arkadiy I. Garber, Lisa N. Christensen, Milana Yagudaeva, Jacob A. Cram, Michael L. McCormick, Gordon T. Taylor","doi":"10.1002/lno.70096","DOIUrl":"https://doi.org/10.1002/lno.70096","url":null,"abstract":"Microbial processes regulating carbon cycling in ancient oceans remain poorly understood, yet characterizing these processes is critical for understanding early Earth biogeochemistry. Here, we investigate microbial communities associated with sinking particles regulating carbon cycling in meromictic Fayetteville Green Lake, a mid‐Proterozoic marginal ocean analog. The lake's photic zone spans oxic through sulfidic conditions, where prokaryotic photoautotrophs contribute to sinking fluxes and organotrophs mediate remineralization across redox and irradiance gradients. To characterize microbial communities in the sinking flux over time and redox condition, we sequenced 16S rRNA amplicons recovered from sediment traps throughout the lake's water column over the course of an annual photoautotroph bloom. Purple sulfur bacteria dominated deep fluxes, while cyanobacteria and green sulfur bacteria contributed variably across depths but were more abundant in suspended communities. As the bloom waned, chemoautotrophic Epsilonbacteraeota gained dominance in deeper fluxes, possibly due to niche partitioning. The shallow flux was remineralized by microbes exposed to temporally fluctuating biogeochemical conditions. Putative temporal changes in the availability and quality of organic matter and terminal electron acceptors thus promoted a succession of low‐diversity communities with few dominant hydrolytic and acidogenic clades. Unchanging conditions at depth promoted higher diversity microbial communities with niches for specialists dominated by sulfur‐metabolizing and fermentative clades. These findings improve our understanding of carbon cycling in the ancient ocean and offer insights into future shifts under climate change and meromixis in lakes.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"9 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144153311","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":"Experimental evidence of dust‐driven shifts in production, chlorophyll a, and community composition in mountain lakes","authors":"Jiahao Wen, Sarah C. P. Chan, Zachary T. Aanderud, Jill S. Baron, Sudeep Chandra, James J. Elser, DeTiare L. Leifi, Erin Suenaga, Bonnie G. Waring, Janice Brahney","doi":"10.1002/lno.70061","DOIUrl":"https://doi.org/10.1002/lno.70061","url":null,"abstract":"Drought and human land use have increased dust emissions in the western United States. However, the ecological sensitivity of remote lakes to dust deposition is not well understood and to date has largely been assessed through spatial and temporal correlations. Using in situ bioassays, we investigated the effects of dust enrichment on the production, chlorophyll <jats:italic>a</jats:italic> (Chl <jats:italic>a</jats:italic>) concentration, and taxonomic composition of phytoplankton and microbial communities in three western US mountain lakes. We found that dust‐derived nutrients increased Chl <jats:italic>a</jats:italic> concentration in all three lakes, but the magnitude of the effect varied from 32% to 226%. This variation was related to pre‐existing lake conditions, such as trophic status, pH, and nutrient limitation. In Castle Lake, co‐limited by N and P, dust bioassays showed an increase in Chl <jats:italic>a</jats:italic> content per cell but suppressed primary production and increased dark <jats:sup>14</jats:sup>C uptake. In contrast, both Flathead Lake and The Loch were primarily P‐limited and exhibited increases in Chl <jats:italic>a</jats:italic> concentration. The contrasting Chl <jats:italic>a</jats:italic> and primary production results from Castle Lake are consistent with the alleviation of nitrogen limitation where energy Adenosine triphosphate (ATP) is used for nutrient assimilation instead of carbon fixation. Dust additions also altered the algal and microbial communities. The latter included the addition of new phyla (e.g., <jats:italic>Deinococcota</jats:italic>), indicating that dust‐delivered microbes have the potential to thrive in receiving lakes. Our study provides the first short‐term experimental in situ evidence of rapid ecosystem effects in mountain lakes following dust exposure. The results emphasize the need for continued research in this area to understand interactions of both the short‐ and long‐term consequences of dust‐induced perturbations in remote lakes in the context of global changes.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"12 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130661","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":"Highly mobile pelagic species co‐occur with fine‐scale ocean fronts","authors":"Alexandre Lhériau‐Nice, Denham G. Cook, Alice Della Penna","doi":"10.1002/lno.70083","DOIUrl":"https://doi.org/10.1002/lno.70083","url":null,"abstract":"Coastal areas are an important source of food and a valuable tourism asset for communities, but also highly dynamic and heterogeneous environments. Understanding how marine species respond to the variability of their habitat is essential to sustainably manage coastal resources. Here we investigate the distribution of highly mobile marine species in relation to fine‐scale fronts (&lt; 10 km) in North‐East Aotearoa New Zealand. We use fishery dependent catch and aerial observations to assess species distribution and compare their locations to the position of fronts tracked using high‐resolution ocean color images. We find significant aggregation near fine‐scale surface chlorophyll <jats:italic>a</jats:italic> fronts for most species considered. Specifically blue mackerel, kahawai, and jack mackerel are most often found in regions of moderate to high chlorophyll <jats:italic>a</jats:italic> and characterized by strong spatial gradients in ocean color. On the other hand, seabirds and mammals collocated most often with higher chlorophyll <jats:italic>a</jats:italic> concentrations and lower gradients compared to the other species examined. These findings advance our understanding of how mobile marine species interact with fine‐scale coastal fronts, suggesting that these features and their variability need to be accounted explicitly for habitat modeling and effective management.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"141 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144130662","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":"Plankton communities today and tomorrow—potential impacts of multiple global change drivers and marine heatwaves","authors":"Cédric L. Meunier, Josefin Schmidt, Antonia Ahme, Areti Balkoni, Katharina Berg, Lea Blum, Maarten Boersma, Jan D. Brüwer, Bernhard M. Fuchs, Luis Gimenez, Maïté Guignard, Ruben Schulte‐Hillen, Bernd Krock, Johannes Rick, Herwig Stibor, Maria Stockenreiter, Simon Tulatz, Felix Weber, Antje Wichels, Karen Helen Wiltshire, Sylke Wohlrab, Inga V. Kirstein","doi":"10.1002/lno.70042","DOIUrl":"https://doi.org/10.1002/lno.70042","url":null,"abstract":"In the context of global change, marine organisms are subjected not only to gradual changes in abiotic parameters, but also to an increasing number of extreme events, such as heatwaves. However, we still know little about the influence of heatwaves on the structure of marine communities, and experimental studies are needed to test the impact of heatwaves alone and in combination with other environmental drivers. Here, we conducted a mesocosm experiment to assess the potential impact of heatwaves on plankton communities, which we did under ambient and future environmental conditions. To simulate future environmental conditions, we simultaneously manipulated temperature and pH based on IPCC predictions for 2100, and dissolved N : P ratios based on the conditions expected in European coastal zones. While we did not observe any effects of simulated heatwaves on phytoplankton abundances, we identified that future environmental conditions may favor smaller phytoplankton species and that additional heatwaves may especially favor small phytoflagellates and coccolithophores. We also observed that future environmental conditions may reduce the abundances and modify the species composition of bacterioplankton, microzooplankton, and mesozooplankton, and that heatwaves may exacerbate these effects. Using a unique approach to examine the potential impacts of heatwaves under current and future environmental conditions on a natural multi‐trophic marine plankton community, we show that the combination of multiple global change drivers has the potential to perturb the entire basis of marine food webs.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"8 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113423","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":"Ecogenomics and limnological dynamics of a new Thiocapsa species blooming in the whole water column of a karstic lake","authors":"Pedro J. Cabello‐Yeves, Antonio Picazo, Carlos Rochera, Daniel Morant, Eduardo Vicente, David J. Scanlan, Richard J. Puxty, Antonio Camacho","doi":"10.1002/lno.70052","DOIUrl":"https://doi.org/10.1002/lno.70052","url":null,"abstract":"Purple sulfur bacteria (PSB) of the family Chromatiaceae (Gammaproteobacteria) can perform chemo‐ and photo‐lithoautotrophy (through anoxygenic photosynthesis) in anoxic layers of freshwater stratified (including meromictic) lakes. This group has been extensively studied via physiological and ecological approaches, albeit their genomics has lagged behind. Here, we monitored a small, shallow, karstic lake, Lagunillo de Cardenillas, that developed a pink coloration throughout the whole water column and prevailed for ca. 2 years across seasons of the limnological cycle. Combining the study of physical/chemical parameters, amplicon sequencing, metagenomics, genomics, and microscopy, we observed this phenomenon was caused by blooms of a novel <jats:italic>Thiocapsa</jats:italic> species, which represented ca. 40% of the total microbial biomass of the lake's water column during the autumn/winter mixing period, and ca. 36% in the anoxic layers during spring/summer stratification. The dominance of this microbe was attributed to the high sulfur concentrations and biogeochemical features of the lake combined with various genomic footprints/abilities of this microbe to utilize different nutrient sources under anoxic and oxic/microaerophilic conditions. The latter included nitrogen (cyanate and ethanolamine hydrolysis, N fixation, dissimilatory nitrate reduction, ammonia assimilation, denitrification), carbon (anoxygenic photosynthesis and the presence of α‐carboxysomes and type IA RuBisCOs) and sulfur (dimethylsulfide [DMS] and thiosulfate oxidation, dimethylsulfoxide [DMSO] reduction). In addition, this novel species possessed genes for gas vesicle formation, anoxic/oxic respiration pathways, hydrogenases, oxic stress response, and a CRISPR‐Cas array. Thus, its extensive genomic repertoire helped explain its versatility and success in colonizing both the anoxic layers and the oxic/anoxic interphase in this lake.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"55 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104191","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":"Regulation of surface carbon dioxide distributions and air–sea fluxes by temperature, biology, and mixing along the North American Atlantic Coastal Ocean Margin","authors":"Zelun Wu, Xinyu Li, Zhangxian Ouyang, Wei‐Jun Cai","doi":"10.1002/lno.70073","DOIUrl":"https://doi.org/10.1002/lno.70073","url":null,"abstract":"The North American Atlantic Coastal Ocean Margin (NAACOM) was recognized as an atmospheric carbon dioxide (CO<jats:sub>2</jats:sub>) sink, with large uncertainties in its northern areas due to complex dynamics in controlling the spatiotemporal variability of surface partial pressure of CO<jats:sub>2</jats:sub> (<jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub>) and limited <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> observations. Here, we used a regional reconstructed product to investigate the spatial and seasonal variability of <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> and air–sea CO<jats:sub>2</jats:sub> fluxes across the region during 1993–2021. Decomposition of <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> variability reveals temperature as the primary driver in southern sub‐regions (Gulf of Mexico, South and Mid Atlantic Bight), while both thermal and nonthermal processes dominate in the north (Gulf of Maine, Scotian Shelf, Gulf of St. Lawrence, and Grand Banks), with winter deep mixing leading to <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> elevation, and spring phytoplankton production significantly influencing <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> drawdown. These regional differences in local dynamics result in greater air–sea CO<jats:sub>2</jats:sub> disequilibrium in the north, driving larger seasonal <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> amplitudes, and a pronounced south‐to‐north decreasing gradient. We identified the entire region as a CO<jats:sub>2</jats:sub> sink, with fluxes of −0.63 ± 0.19 and −0.60 ± 0.21 mol C m<jats:sup>−2</jats:sup> yr<jats:sup>−1</jats:sup> (10.14 ± 3.00 and 24.24 ± 8.31 Tg C yr<jats:sup>−1</jats:sup>), respectively, in the narrow (depth &lt; 200 m) and wide (distance from shoreline &lt; 400 km) ocean margins. The updated wide‐margin CO<jats:sub>2</jats:sub> uptake is 61% lower than previous reports. This 29‐yr analysis elucidates the drivers of <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> variability across the diverse NAACOM, highlighting the importance of regional <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> products for improving coastal carbon systems projections in a changing climate.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"44 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113424","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":"RETRACTION: Future Warming Stimulates Growth and Photosynthesis in an Arctic Microalga More Strongly than Changes in Light Intensity or pCO2","authors":"","doi":"10.1002/lno.70094","DOIUrl":"https://doi.org/10.1002/lno.70094","url":null,"abstract":"<jats:mixed-citation publication-type=\"journal\">RETRACTION: <jats:string-name><jats:given-names>S.D.</jats:given-names> <jats:surname>Rokitta</jats:surname> </jats:string-name>, <jats:string-name><jats:given-names>C.H.</jats:given-names> <jats:surname>Grossmann</jats:surname> </jats:string-name>, <jats:string-name><jats:given-names>E.</jats:given-names> <jats:surname>Werner</jats:surname> </jats:string-name>, <jats:string-name><jats:given-names>J.</jats:given-names> <jats:surname>Moye</jats:surname> </jats:string-name>, <jats:string-name><jats:given-names>G.</jats:given-names> <jats:surname>Castellani</jats:surname> </jats:string-name>, <jats:string-name><jats:given-names>E.M.</jats:given-names> <jats:surname>Nöthig</jats:surname> </jats:string-name>, and <jats:string-name><jats:given-names>B.</jats:given-names> <jats:surname>Rost</jats:surname> </jats:string-name>, “,” <jats:source>Limnology and Oceanography</jats:source> <jats:volume>68</jats:volume>, no. (<jats:year>2023</jats:year>): <jats:fpage>2789</jats:fpage>–<jats:lpage>2799</jats:lpage>, <jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"https://doi.org/10.1002/lno.12460\">https://doi.org/10.1002/lno.12460</jats:ext-link>.</jats:mixed-citation>The above article, published online on 29 November 2023 in Wiley Online Library (<jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"http://wileyonlinelibrary.com\">wileyonlinelibrary.com</jats:ext-link>), has been retracted by agreement between the authors; the journal Editor‐in‐Chief, K. David Hambright; and John Wiley &amp; Sons, Inc. The retraction has been agreed due to an error in the identification of a species in the study. Subsequent sequencing runs performed by the authors revealed that the alga species was not <jats:italic>Phaeocystis pouchetii</jats:italic> as originally reported but rather was identified as <jats:italic>Isochrysis,</jats:italic> a closely related haptophyte. As a result, the conclusions reported in the article are not considered reliable, as they pertain to a different taxon than originally reported. A revised version of this article will be submitted for consideration for publication.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"99 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104192","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":"Pre‐existing phytoplankton biomass concentrations shape coastal plankton response to fire‐generated ash leachate","authors":"Nicholas Baetge, Kimberly H. Halsey, Erin J. Hanan, Michael J. Behrenfeld, Allen J. Milligan, Jason R. Graff, Parker Hansen, Craig A. Carlson, Rene M. Boiteau, Eleanor C. Arrington, Jacqueline Comstock, Elisa R. Halewood, Elizabeth L. Harvey, Norman B. Nelson, Keri Opalk, Brian Ver Wey","doi":"10.1002/lno.70087","DOIUrl":"https://doi.org/10.1002/lno.70087","url":null,"abstract":"Climate‐driven warming is projected to intensify wildfires, increasing their frequency and severity globally. Wildfires are an increasingly significant source of atmospheric deposition, delivering nutrients, organic matter, and trace metals to coastal and open ocean waters. These inputs have the potential to fertilize or inhibit microbial growth, yet their ecological impacts remain poorly understood. This study examines how ash leachate, derived from the 2017 Thomas Fire in California and lab‐produced ash from Oregon vegetation, affects coastal plankton communities. Shipboard experiments off the California coast examined how pre‐existing plankton biomass concentrations mediate responses to ash leachates. We found that ash leachate contained dissolved organic matter (DOM) that significantly increased bacterioplankton specific growth rates and DOM remineralization rates but had a negligible effect on bacterioplankton growth efficiency, suggesting low DOM bioavailability. Furthermore, ash‐derived DOM had a higher potential to accumulate in high biomass water, where pre‐existing DOM substrates may better support bacterial metabolism. Ash leachate had a neutral to negative effect on phytoplankton division rates and decreased microzooplankton grazing rates, particularly in low biomass water, leading to increased phytoplankton accumulation. Nanoeukaryotes accumulated in low biomass water, whereas picoeukaryotes and <jats:italic>Synechococcus</jats:italic> accumulated in high biomass water. Our findings suggest that the influence of ash deposition on DOM cycling, phytoplankton accumulation, and broader marine food web dynamics depends on pre‐existing biomass levels. Understanding these interactions is critical for predicting the biogeochemical consequences of increasing wildfire activity on marine ecosystems.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"3 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113425","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}