Biogeochemistry最新文献

{"title":"Inorganic carbon removal from alkaline soils: an underappreciated influence on soil organic carbon measurements in an elevated CO2 experiment","authors":"Kelsey H. Jensen,&nbsp;Jed P. Sparks","doi":"10.1007/s10533-023-01073-4","DOIUrl":"10.1007/s10533-023-01073-4","url":null,"abstract":"<div><p>Isolating soil organic carbon (SOC) from soil inorganic carbon (SIC) is necessary to quantify SOC stocks and understanding SOC dynamics. Inorganic acids are commonly used to remove SIC and several methods have been developed to minimize the impacts these acid treatments have on the residual SOC. Negative impacts on the SOC pool, such as underestimating SOC stocks, are caused in part due to differences in the amount and composition of the organic matter pool. The effects of SIC removal on SOC are often ignored within experimental studies based on the assumption that soils from the same site do not differ enough to impact results. However, some experimental treatments, such as elevated atmospheric CO₂, change SOC pools in both concentration and composition. Therefore, SIC removal can introduce different biases in control and treatment soils that may differ by method. In this work, we compare two commonly used methods of SIC removal on a set of soil samples from the same elevated CO₂?experiment. We use soils from the Nevada Desert Free Air Carbon dioxide Enrichment Facility to quantify how SIC removal with either acid washing or acid fumigation affect SOC in control and elevated CO₂ plots. We then use the difference in SOC (%C and δ¹³C) between methods to infer changes in the SOC pool driven by the elevated CO₂ treatment. Our results show that acid washing underestimates SOC relative to fumigation and that this difference is larger in soils from control CO₂ plots than elevated CO₂ plots. This may suggest that stabilization mechanisms sensitive to acidification, such as calcium bridging, are disrupted under elevated CO₂ treatment and therefore are less susceptible to SOC loss during acid washing. Our results present future research avenues for exploring the effects of acidic organic compounds, such as root exudates, on SOC stability in alkaline soils.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"15 - 27"},"PeriodicalIF":4.0,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4237836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A soil matrix capacity index to predict mineral-associated but not particulate organic carbon across a range of climate and soil pH","authors":"Alison E. King,&nbsp;Joseph P. Amsili,&nbsp;S. Carolina Córdova,&nbsp;Steve Culman,&nbsp;Steven J. Fonte,&nbsp;James Kotcon,&nbsp;Mark Liebig,&nbsp;Michael D. Masters,&nbsp;Kent McVay,&nbsp;Daniel C. Olk,&nbsp;Meagan Schipanski,&nbsp;Sharon K. Schneider,&nbsp;Catherine E. Stewart,&nbsp;M. Francesca Cotrufo","doi":"10.1007/s10533-023-01066-3","DOIUrl":"10.1007/s10533-023-01066-3","url":null,"abstract":"<div><p>Understanding controls on soil organic carbon (SOC) will be crucial to managing soils for climate change mitigation and food security. Climate exerts an overarching influence on SOC, affecting both carbon (C) inputs to soil and soil physicochemical properties participating in C retention. To test our hypothesis that climate, C inputs, and soil properties would differently affect particulate organic carbon (POC) and mineral-associated organic carbon (MAOC), we sampled 16 agricultural sites (n?=?124 plots) in the United States, ranging in climate (mean annual precipitation (MAP)—potential evapotranspiration (PET; MAP-PET)), soil pH (5.8–7.9), and soil texture (silt?+?clay?=?13–96%). As MAP-PET increased, soils increased in oxalate-extractable iron (Fe_O) and aluminum (Al_O), decreased in exchangeable calcium (Ca_ex) and magnesium (Mg_ex), and received greater C inputs. Soil physicochemical properties did not strongly predict POC, confirming the relative independence of this SOC fraction from the soil matrix. In contrast, MAOC was well predicted by combining Al_O?+?[1/2]Fe_O with Ca_ex?+?Mg_ex in a ‘matrix capacity index’, which performed better than individual soil physicochemical properties across all pH levels (r?&gt;?0.79). Structural equation modeling indicated a similar total effect of MAP-PET on MAOC and POC, which was mediated by total C inputs and the matrix capacity index for MAOC but not POC. Our results emphasize the need to separately conceptualize controls on MAOC and POC and justify the use of a unified soil matrix capacity index for predicting soil MAOC storage.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"1 - 14"},"PeriodicalIF":4.0,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4756919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of storm disturbance and the role of the Feammox process in high nutrient riparian sediments","authors":"Arianna E. Sherman,&nbsp;Shan Huang,&nbsp;Peter R. Jaffé","doi":"10.1007/s10533-023-01062-7","DOIUrl":"10.1007/s10533-023-01062-7","url":null,"abstract":"<div><p>The extensive agricultural feedlot operations in the Neuse River Watershed (NRW) in North Carolina result in high nutrient loading, particularly of ammonium (NH₄⁺). In September 2018, Hurricane Florence devastated large portions of the NRW, creating a unique opportunity to study the impact of such hydrological events on the biogeochemistry of riverine and riparian sediments. The high NH₄⁺ concentrations, naturally acidic conditions, and elevated levels of ferric iron [Fe(III)] in Neuse River sediments and soils provide an ideal environment for <i>Acidimicrobium</i> sp<i>.</i> A6 (referred to hereon as A6), a bacterium capable of conducting the Feammox process in which NH₄⁺ is oxidized while iron is reduced. A6 was observed in all sediment samples obtained from the Neuse River, and it is therefore predicted that this process may be an important mechanism for NH₄⁺ removal in this river system. Incubations of NRW samples indicate that the NH₄⁺ oxidation potential via the Feammox process in the NRW is comparable with aerobic NH₄⁺ oxidation by heterotrophic microorganisms. Given the high demand for Fe(III) by the Feammox process, it has been unclear how such a process may occur in sedimentary environments where ferric iron [Fe(III)] might be depleted. The results presented here show that a major hydrologic storm event can result in an increase in Fe(III) and in an increase in the abundance of Fe-reducing bacteria, including <i>Acidimicrobium</i> sp<i>.</i> A6. These findings indicate that major hydrologic storm events may, via the delivery of Fe(III), be capable of enhancing Feammox activity in riverine sediments that favor the Feammox process.\u0000</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"113 - 128"},"PeriodicalIF":4.0,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-023-01062-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4345659","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}

{"title":"Association between soil organic carbon and calcium in acidic grassland soils from Point Reyes National Seashore, CA","authors":"Mike C. Rowley,&nbsp;Peter S. Nico,&nbsp;Sharon E. Bone,&nbsp;Matthew A. Marcus,&nbsp;Elaine F. Pegoraro,&nbsp;Cristina Castanha,&nbsp;Kyounglim Kang,&nbsp;Amrita Bhattacharyya,&nbsp;Margaret S. Torn,&nbsp;Jasquelin Peña","doi":"10.1007/s10533-023-01059-2","DOIUrl":"10.1007/s10533-023-01059-2","url":null,"abstract":"<div><p>Organo-mineral and organo-metal associations play an important role in the retention and accumulation of soil organic carbon (SOC). Recent studies have demonstrated a positive correlation between calcium (Ca) and SOC content in a range of soil types. However, most of these studies have focused on soils that contain calcium carbonate (pH?&gt;?6). To assess the importance of Ca-SOC associations in lower pH soils, we investigated their physical and chemical interaction in the grassland soils of Point Reyes National Seashore (CA, USA) at a range of spatial scales. Multivariate analyses of our bulk soil characterisation dataset showed a strong correlation between exchangeable Ca (Ca_Exch; 5–8.3 c.mol_c kg^?1) and SOC (0.6–4%) content. Additionally, linear combination fitting (LCF) of bulk Ca K-edge X-ray absorption near-edge structure (XANES) spectra revealed that Ca was predominantly associated with organic carbon across all samples. Scanning transmission X-ray microscopy near-edge X-ray absorption fine structure spectroscopy (STXM C/Ca NEXAFS) showed that Ca had a strong spatial correlation with C at the microscale. The STXM C NEXAFS K-edge spectra indicated that SOC had a higher abundance of aromatic/olefinic and phenolic C functional groups when associated with Ca, relative to C associated with Fe. In regions of high Ca-C association, the STXM C NEXAFS spectra were similar to the spectrum from lignin, with moderate changes in peak intensities and positions that are consistent with oxidative C transformation. Through this association, Ca thus seems to be preferentially associated with plant-like organic matter that has undergone some oxidative transformation, at depth in acidic grassland soils of California. Our study highlights the importance of Ca-SOC complexation in acidic grassland soils and provides a conceptual model of its contribution to SOC preservation, a research area that has previously been unexplored.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"91 - 111"},"PeriodicalIF":4.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-023-01059-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4304996","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}

{"title":"Experimental flooding shifts carbon, nitrogen, and phosphorus pool distribution and microbial activity","authors":"Hannah P. Lieberman,&nbsp;Maia Rothman,&nbsp;Christian von Sperber,&nbsp;Cynthia M. Kallenbach","doi":"10.1007/s10533-023-01061-8","DOIUrl":"10.1007/s10533-023-01061-8","url":null,"abstract":"<div><p>Flooding transforms the soil environment, impacting small-scale controls on mineral associated carbon (C), nitrogen (N) and phosphorus (P) persistence and mobilization. Yet during flood events, mineral associated C, N, and P may not respond in the same way, such that soluble C, N, and P concentrations and stoichiometry may change potentially impacting microbial activity. Using a laboratory incubation approach, we investigated how flooding impacts C, N, and P pool distribution and microbial activity across a 1-week flood event and after drying. We found that all three mineral associated pools responded dynamically to flooding, increasing and decreasing throughout the flood with a 5.9% increase in mineral associated C and 32.5% decrease in residual P post flood. However, mineral associated C, N, and P each shifted at different temporal points, indicating that they are likely responding to separate destabilization mechanisms working at different temporal scales. Soluble C increased by 57% and soluble N decreased by 72% at the beginning of the flood which remained post-flood. However, soluble P behaved more similarly to the mineral associated pool, shifting throughout the flood period. The microbial community maintained and even increased their exo-cellular activity throughout the flood period. Our research demonstrates that the mineral associated pool can shift with short-term flooding altering the composition and quantity of the soluble pool and microbial activity.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"75 - 90"},"PeriodicalIF":4.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4305663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Storms and pH of dam releases affect downstream phosphorus cycling in an arid regulated river","authors":"Bridget R. Deemer,&nbsp;Robin H. Reibold,&nbsp;Anna Fatta,&nbsp;Jessica R. Corman,&nbsp;Charles B. Yackulic,&nbsp;Sasha C. Reed","doi":"10.1007/s10533-023-01064-5","DOIUrl":"10.1007/s10533-023-01064-5","url":null,"abstract":"<div><p>Reservoirs often bury phosphorus (P), leading to seasonal or persistent reductions in P supply to downstream rivers. Here we ask if observed variation in the chemistry of dam release waters stimulates downstream sediment P release and biological activity in an arid, oligotrophic system, the Colorado River below Lake Powell, Arizona, USA. We use bottle incubations to simulate a range of observed pH (6–8.8) and oxygen (0–9.4?mg L^?1) levels, with the hypothesis that either oxygen concentrations or pH regulates P release from sediments to the water column. We found support for pH-mediated P release from calcite across the three sites we sampled. The magnitude of this effect was lower in bottles filled with tailwater sediment, but at downriver sites low pH resulted in declining water column dissolved inorganic nitrogen:soluble reactive P (DIN:SRP) ratios, which dropped below the Redfield ratio of 16:1, increasing water column total protein production, and down-regulating alkaline phosphatase production. Additional 7-day incubations showed that tributary storm inputs can temporarily elevate riverine P availability from &lt;?1.5?μg L^?1 total dissolved P (TDP) pre-storm to 6.7?μg L^?1 TDP post storm. Taken together, our lab incubation and long-term observational results highlight the importance of pH, and ultimately reservoir management and storm dynamics, in regulating P availability and biological processes both now and into the future.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"57 - 74"},"PeriodicalIF":4.0,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4256738","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial patterns of nitrogen isotope ratios in forest soils are related to latitude and soil phosphorus concentration","authors":"Marie Spohn,&nbsp;Johan Stendahl","doi":"10.1007/s10533-023-01058-3","DOIUrl":"10.1007/s10533-023-01058-3","url":null,"abstract":"<div><p>The aim of this study was to identify the parameters that affect the nitrogen (N) isotope ratio (δ¹⁵N) in soils of temperate and boreal forests. We measured the δ¹⁵N in 30 soil profiles of temperate and boreal forests in Sweden and analyzed the relationships between δ¹⁵N in the soils and soil chemical properties as well as site characteristics. In addition, we conducted a meta-analyses of δ¹⁵N in the organic layer of European forests. We identified two types of δ¹⁵N patterns; in type D soils, the δ¹⁵N in the mineral soil decreases with depth, whereas in type C soil, the δ¹⁵N in the soil profile is almost constant. Type D soils had a significantly higher δ¹⁵N in the organic layer and upper mineral soil than type C soils, which is likely due to N isotope fractionation by ectomycorrhizal fungi?in the topsoil. Type D soils were found in boreal forests, but not in temperate forests. They had a significantly lower atmospheric N deposition rate than type C soils, by a factor of 2.3, and a significantly higher phosphorus (P) concentration of the organic layer than type C soils, by a factor of 1.5. We also found that the δ¹⁵N was negatively correlated with the N:P ratio of the organic layer (R²?=?0.21, p?&lt;?0.001). Across Europe, the δ¹⁵N of the organic layer was positively correlated with latitude (R²?=?0.58, p?&lt;?0.001), and negatively with mean annual temperature (R²?=?0.52, p?&lt;?0.001) and atmospheric N deposition (R²?=?0.42, p?&lt;?0.001). In conclusion, our results show that the δ¹⁵N of the organic layer and microbial N (re-)cycling in forest soils is positively related with latitude and the P concentration of the organic layer.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"43 - 56"},"PeriodicalIF":4.0,"publicationDate":"2023-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-023-01058-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4942788","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}

{"title":"Detecting land cover and land use change and its impact on biomass carbon emission from 2001 to 2019 in Arkansas, U.S.A","authors":"Weilun Tay,&nbsp;Yaqian He","doi":"10.1007/s10533-023-01042-x","DOIUrl":"10.1007/s10533-023-01042-x","url":null,"abstract":"<div><p>Land cover and land use change (LCLUC) is a significant contributor to the changes in biomass carbon emissions. The state of Arkansas in the U.S.A. has experienced LCLUC over last five decades. This study combined geographic information system (GIS), remote sensing, and spatiotemporal analysis to quantify changes in vegetation carbon storage resulting from LCLUC during 2001–2019. The result showed that there were fluctuating changes among all land cover land use types, while the significant transition occurred mainly between forest and grassland. From 2001 to 2011, there were?~1973.8 km² forest gain, mostly contributed from grassland/shrubland (~1448.8 km²), followed by farmland (~489.5 km²). The?~?3575.3 km² of forest was mainly changed into grassland/shrubland (~3343.4 km²) and built-up land (114.0 km²), leading to a net loss of?~1601.5 km² in forest during this 10-year period. Similarly, the changes of grassland/shrubland, farmland, and built-up land with forest resulted in?~493.1 km² net gain in forest from 2011 to 2019. During the process, a total of?~1.3 million tC biomass carbon was lost over the past 18?years in Arkansas, which is largely because of forest loss. However, due to the regrowth of trees, Arkansas also witnessed carbon gain during some periods. The spatiotemporal change of carbon storage and its drivers revealed by this study provide an important scientific basis for sustainable land use planning in Arkansas.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"165 1","pages":"29 - 42"},"PeriodicalIF":4.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4898762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantifying erosion rates and weathering pathways that maximize soil organic carbon storage","authors":"Joshua J. Roering,&nbsp;Brooke D. Hunter,&nbsp;Ken L. Ferrier,&nbsp;Oliver A. Chadwick,&nbsp;Kyungsoo Yoo,&nbsp;Adrian A. Wackett,&nbsp;Peter C. Almond,&nbsp;Lucas Silva,&nbsp;A. Mark Jellinek","doi":"10.1007/s10533-023-01054-7","DOIUrl":"10.1007/s10533-023-01054-7","url":null,"abstract":"<div><p>Primary minerals that enter soils through bedrock weathering and atmospheric deposition can generate poorly crystalline minerals (PCM) that preferentially associate with soil organic carbon (SOC). These associations hinder microbial decomposition and the release of CO₂ from soils to the atmosphere, making them a critical geochemical control on terrestrial carbon abundance and persistence. Studies that explore these relationships are typically derived from soil chronosequences that experience negligible erosion and thus do not readily translate to eroding landscapes. Here, we propose a theoretical framework to estimate steady-state PCM density and stocks for hilly and mountainous settings by coupling geochemical and geomorphic mass balance equations that account for soil production from bedrock and dust, soil erosion, PCM formation from weathering, and the transformation of PCMs into crystalline phases. We calculate an optimal erosion rate for maximum PCM abundance that arises because PCMs are limited by insufficient weathering at faster erosion rates and loss via “ripening” into more crystalline forms at slower erosion rates. The optimal erosion rate for modeled hilltop soil is modulated by reaction rate constants that govern the efficiency of primary mineral weathering and PCM ripening. By comparing our analysis with global compilations of erosion and soil production rates derived from cosmogenic nuclides, we show that landscapes with slow-to-moderate erosion rates may be optimal for harboring abundant PCM stocks that can facilitate SOC sequestration and limit turnover. Given the growing array of erosion-topography metrics and the widespread availability of high-resolution topographic data, our framework demonstrates how weathering and critical zone processes can be coupled to inform landscape prioritization for persistent SOC storage potential across a broad range of spatial and temporal scales.\u0000</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"164 2","pages":"319 - 333"},"PeriodicalIF":4.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10533-023-01054-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4868893","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}

{"title":"Recent increases of rainfall and flooding from tropical cyclones (TCs) in North Carolina (USA): implications for organic matter and nutrient cycling in coastal watersheds","authors":"Hans W. Paerl,&nbsp;Nathan S. Hall,&nbsp;Alexandria G. Hounshell,&nbsp;Karen L. Rossignol,&nbsp;Malcolm A. Barnard,&nbsp;Richard A. Luettich Jr.,&nbsp;Jacob C. Rudolph,&nbsp;Christopher L. Osburn,&nbsp;Jerad Bales,&nbsp;Lawrence W. Harding Jr.","doi":"10.1007/s10533-021-00770-2","DOIUrl":"10.1007/s10533-021-00770-2","url":null,"abstract":"<div><p>Coastal North Carolina experienced 36 tropical cyclones (TCs), including three floods of historical significance in the past two decades (Hurricanes Floyd-1999, Matthew-2016 and Florence-2018). These events caused catastrophic flooding and major alterations of water quality, fisheries habitat and ecological conditions of the Albemarle-Pamlico Sound (APS), the second largest estuarine complex in the United States. Continuous rainfall records for coastal NC since 1898 reveal a period of unprecedented high precipitation storm events since the late-1990s. Six of seven of the “wettest” storm events in this &gt; 120-year record occurred in the past two decades, identifying a period of elevated precipitation and flooding associated with recent TCs. We examined storm-related freshwater discharge, carbon (C) and nutrient, i.e., nitrogen (N) and phosphorus (P) loadings, and evaluated contributions to total annual inputs in the Neuse River Estuary (NRE), a major sub-estuary of the APS. These contributions were highly significant, accounting for &gt; 50% of annual loads depending on antecedent conditions and storm-related flooding. Depending on the magnitude of freshwater discharge, the NRE either acted as a “processor” to partially assimilate and metabolize the loads or acted as a “pipeline” to transport the loads to the APS and coastal Atlantic Ocean. Under base-flow, terrestrial sources dominate riverine carbon. During storm events these carbon sources are enhanced through the inundation and release of carbon from wetlands. These findings show that event-scale discharge plays an important and, at times, predominant role in C, N and P loadings. We appear to have entered a new climatic regime characterized by more frequent extreme precipitation events, with major ramifications for hydrology, cycling of C, N and P, water quality and habitat conditions in estuarine and coastal waters.</p></div>","PeriodicalId":8901,"journal":{"name":"Biogeochemistry","volume":"164 1","pages":"257 - 276"},"PeriodicalIF":4.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4825714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}