scholarly journals Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems – setting the record straight

2018 ◽  
Vol 15 (22) ◽  
pp. 6791-6818 ◽  
Author(s):  
Ariane Arias-Ortiz ◽  
Pere Masqué ◽  
Jordi Garcia-Orellana ◽  
Oscar Serrano ◽  
Inés Mazarrasa ◽  
...  
Keyword(s):  
Specific Activity ◽  
210Pb Dating ◽  
Coastal Ecosystems ◽  
Carbon Accumulation ◽  
Coastal Sediments ◽  
Tidal Marshes ◽  
Accumulation Rates ◽  
Seagrass Meadows ◽  
Sediment Organic Carbon ◽  
Heterogeneous Sediments

Abstract. Vegetated coastal ecosystems, including tidal marshes, mangroves and seagrass meadows, are being increasingly assessed in terms of their potential for carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg), also termed blue carbon, beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique to determine the rate of Corg accumulation in these habitats. We review the most widely used 210Pb dating models to assess their limitations in these ecosystems, often composed of heterogeneous sediments with varying inputs of organic material, that are disturbed by natural and anthropogenic processes resulting in sediment mixing and changes in sedimentation rates or erosion. Through a range of simulations, we consider the most relevant processes that impact the 210Pb records in vegetated coastal ecosystems and evaluate how anomalies in 210Pb specific activity profiles affect sediment and Corg accumulation rates. Our results show that the discrepancy in sediment and derived Corg accumulation rates between anomalous and ideal 210Pb profiles is within 20 % if the process causing such anomalies is well understood. While these discrepancies might be acceptable for the determination of mean sediment and Corg accumulation rates over the last century, they may not always provide a reliable geochronology or historical reconstruction. Reliable estimates of Corg accumulation rates might be difficult at sites with slow sedimentation, intense mixing and/or that are affected by multiple sedimentary processes. Additional tracers or geochemical, ecological or historical data need to be used to validate the 210Pb-derived results. The framework provided in this study can be instrumental in reducing the uncertainties associated with estimates of Corg accumulation rates in vegetated coastal sediments.

scholarly journals Reviews and syntheses: <sup>210</sup>Pb-derived sediment and carbon accumulation rates in vegetated coastal ecosystems: setting the record straight

2018 ◽  
Author(s):  
Ariane Arias-Ortiz ◽  
Pere Masqué ◽  
Jordi Garcia-Orellana ◽  
Oscar Serrano ◽  
Inés Mazarrasa ◽  
...  
Keyword(s):  
210Pb Dating ◽  
Coastal Ecosystems ◽  
Carbon Accumulation ◽  
Coastal Sediments ◽  
Geochemical Data ◽  
Accumulation Rates ◽  
Sediment Organic Carbon ◽  
The Status ◽  
Heterogeneous Sediments

Abstract. Vegetated coastal ecosystems, including tidal marsh, mangrove and seagrass, are being increasingly assessed for their potential in carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg) beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique as a practical tool to measure the rate of Corg accumulation in vegetated coastal ecosystems. We critically review the status of 210Pb dating methods of vegetated coastal sediments and assess the limitations that apply to these ecosystems, which are often composed by heterogeneous sediments, abundant in coarse particles, with varying inputs of organic material, and are disturbed by natural and anthropogenic processes causing sediment mixing, changes in sedimentation rates or erosion. Through a range of simulations, we discuss the most relevant processes that impact the 210Pb record in vegetated coastal ecosystems and evaluate the deviations in sediment and Corg accumulation rates produced by anomalies in 210Pb profiles. Our results show that the deviation in the determination of sediment and derived Corg accumulation rates is within 20 % confirming that the 210Pb dating technique is secure. However, while these uncertainties might be acceptable for the determination of mean sediment and Corg accumulation rates over the last century, they may not always allow the determination of a detailed geochronology, historical reconstruction, or to ascertain rates of change and fluxes. Additional tracers or geochemical data need to be used in concert to constrain the 210Pb-derived results and to properly interpret the processes recorded in vegetated coastal sediments. The framework provided in this study can be instrumental in reducing the uncertainties associated to the estimates of Corg accumulation rates in vegetated coastal sediments.

scholarly journals Factors Influencing Carbon Stocks and Accumulation Rates in Eelgrass Meadows Across New England, USA

2020 ◽  
Vol 43 (8) ◽  
pp. 2076-2091 ◽  
Author(s):  
A. B. Novak ◽  
M. C. Pelletier ◽  
P. Colarusso ◽  
J. Simpson ◽  
M. N. Gutierrez ◽  
...  
Keyword(s):  
Grain Size ◽  
New England ◽  
Structural Characteristics ◽  
Sediment Cores ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Accumulation Rates ◽  
Seagrass Meadows ◽  
Terrestrial Habitats ◽  
C And N

Abstract Increasing the protection of coastal vegetated ecosystems has been suggested as one strategy to compensate for increasing carbon dioxide (CO2) in the atmosphere as the capacity of these habitats to sequester and store carbon exceeds that of terrestrial habitats. Seagrasses are a group of foundation species that grow in shallow coastal and estuarine systems and have an exceptional ability to sequester and store large quantities of carbon in biomass and, particularly, in sediments. However, carbon stocks (Corg stocks) and carbon accumulation rates (Corg accumulation) in seagrass meadows are highly variable both spatially and temporally, making it difficult to extrapolate this strategy to areas where information is lacking. In this study, Corg stocks and Corg accumulation were determined at 11 eelgrass meadows across New England, representing a range of eutrophication and exposure conditions. In addition, the environmental factors and structural characteristics of meadows related to variation in Corg stocks were identified. The objectives were accomplished by assessing stable isotopes of δ13C and δ15N as well as %C and %N in plant tissues and sediments, measuring grain size and 210Pb of sediment cores, and through assessing site exposure. Variability in Corg stocks in seagrass meadows is well predicted using commonly measured environmental variables such as grain size distribution. This study allows incorporation of data and insights for the northwest Atlantic, where few studies on carbon sequestration by seagrasses have been conducted.

The Distribution of Photoassimilated Carbon and the Growth of Douglas-fir Seedlings

1975 ◽  
Vol 5 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Warren L. Webb
Keyword(s):  
Specific Activity ◽  
Douglas Fir ◽  
Carbon Accumulation ◽  
Accumulation Rates ◽  
Phenological Observation ◽  
Bud Set ◽  
New System ◽  
Observation Results ◽  
Constant Specific Activity

Two-year-old Douglas-fir seedlings accumulated photoassimilated carbon in the tissues of new needles, previous years' needles, new shoots, stem, and roots at rates relative to tissue carbon of 1.25, 0.57, 0.42, 0.60, 0.61%/d, respectively. These daily net accumulation rates were measured just after bud set, and the rates parallel the carbon accumulation expected based on phenological observation. Results were obtained with a new system for long-term labelling of groups of seedlings with 14CO2 at a constant specific activity. This system is described.

scholarly journals Tidal marsh restoration enhances sediment accretion and carbon accumulation in the Stillaguamish River estuary, Washington

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257244
Author(s):  
Katrina L. Poppe ◽  
John M. Rybczyk
Keyword(s):  
Pacific Northwest ◽  
Puget Sound ◽  
River Estuary ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Tidal Marshes ◽  
Accumulation Rates ◽  
Sea Levels ◽  
Accretion Rates ◽  
Rising Sea Levels

Tidal marshes have been recognized globally for their ability to sequester “blue carbon” but there is still a need for studies investigating the marsh response to restoration, particularly in the Pacific Northwest United States. Here we report carbon stocks and accumulation rates for restored and natural tidal marshes in the Stillaguamish River estuary in Puget Sound, Washington, where a 60-hectare marsh was reintroduced to the tidal regime from its previous use as diked and drained farmland. We found that the restoration not only maximized carbon accumulation but also enhanced resilience to rising sea levels. Four years after restoration, mean sediment carbon stocks in the upper 30 cm within the restored marsh (4.43 kg C m-2) were slightly lower than those measured in the adjacent natural marshes (5.95 kg C m-2). Mean carbon accumulation rates, however, were nearly twice as high in the restored marsh (230.49 g C m-2 yr-1) compared to the natural marshes (123.00 g C m-2 yr-1) due to high rates of accretion in the restored marsh (1.57 cm yr-1). Mean elevation change rates were nearly twice that of corresponding 210Pb accretion rates, but all were greater than the current rate of sea level rise.

Carbon accumulation rates recorded in the last 150 years in tropical high mountain peatlands of the Atlantic Rainforest, SE - Brazil

2017 ◽  
Vol 579 ◽  
pp. 439-446 ◽  
Author(s):  
Lúcio F. Lourençato ◽  
Pedro P. Caldeira ◽  
Marcelo C. Bernardes ◽  
Andressa C. Buch ◽  
Daniel C. Teixeira ◽  
...  
Keyword(s):  
Carbon Accumulation ◽  
Atlantic Rainforest ◽  
High Mountain ◽  
Accumulation Rates ◽  
Se Brazil ◽  
Carbon Accumulation Rates ◽  
Mountain Peatlands

scholarly journals Monitoring oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast, Japan before and after the 2011 tsunami by remote sensing: their recoveries implying the sustainable development of coastal waters

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10727
Author(s):  
Hiroki Murata ◽  
Motoyuki Hara ◽  
Chinatsu Yonezawa ◽  
Teruhisa Komatsu
Keyword(s):  
Remote Sensing ◽  
Sustainable Development ◽  
Coastal Waters ◽  
Coastal Ecosystems ◽  
Oyster Culture ◽  
Sanriku Coast ◽  
The Sustainable Development ◽  
Seagrass Meadows ◽  
Before And After ◽  
Aquaculture Management

Background Coastal ecosystems are blue infrastructures that support coastal resources and also aquaculture. Seagrass meadows, one of coastal ecosystems, provide substrates for epiphytic diatoms, which are food resources for cultured filter feeder organisms. Highly intensive coastal aquaculture degrades coastal environments to decrease seagrass meadows. Therefore, efficient aquaculture management and conservation of seagrass meadows are necessary for the sustainable development of coastal waters. In ria-type bays, non-feeding aquaculture of filter feeders such as oysters, scallops, and ascidians are actively practiced along the Sanriku Coast, Japan. Before the 2011 Great East Japan Earthquake, the over-deployment of oyster culture facilities polluted the bottom environment and formed an hypoxic bottom water layer due to the organic excrements from cultured oysters. The tsunami in 2011 devastated the aquaculture facilities and seagrass meadows along the Sanriku Coast. We mapped the oyster culture rafts and seagrass meadows in Nagatsura-ura Lagoon, Sanriku Coast before and after the tsunami and monitored those and environments after the tsunami by field surveys. Methods We conducted field surveys and monitored the environmental parameters in Nagatsura-ura Lagoon every month since 2014. We used high-resolution satellite remote sensing images to map oyster culture rafts and seagrass meadows at irregular time intervals from 2006 to 2019 in order to assess their distribution. In 2019, we also used an unmanned aerial vehicle to analyze the spatial variability of the position and the number of ropes suspending oyster clumps beneath the rafts. Results In 2013, the number and distribution of the oyster culture rafts had been completely restored to the pre-tsunami conditions. The mean area of culture raft increased after the tsunami, and ropes suspending oyster clumps attached to a raft in wider space. Experienced local fishermen also developed a method to attach less ropes to a raft, which was applied to half of the oyster culture rafts to improve oyster growth. The area of seagrass meadows has been expanding since 2013. Although the lagoon had experienced frequent oyster mass mortality events in summer before the tsunami, these events have not occurred since 2011. The 2011 earthquake and tsunami deepened the sill depth and widened the entrance to enhance water exchange and improve water quality in the lagoon. These changes brought the expansion of seagrass meadows and reduction of mass mortality events to allow sustainable oyster culture in the lagoon. Mapping and monitoring of seagrass meadows and aquaculture facilities via satellite remote sensing can provide clear visualization of their temporal changes. This can in turn facilitate effective aquaculture management and conservation of coastal ecosystems, which are crucial for the sustainable development of coastal waters.

scholarly journals Sediment and carbon accumulation in a glacial lake in Chukotka (Arctic Siberia) during the Late Pleistocene and Holocene: combining hydroacoustic profiling and down-core analyses

2021 ◽  
Vol 18 (16) ◽  
pp. 4791-4816
Author(s):  
Stuart A. Vyse ◽  
Ulrike Herzschuh ◽  
Gregor Pfalz ◽  
Lyudmila A. Pestryakova ◽  
Bernhard Diekmann ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Sediment Core ◽  
Boreal Lakes ◽  
Carbon Accumulation ◽  
Carbon Budgets ◽  
Accumulation Rates ◽  
Glacial Lakes ◽  
Organic Carbon Pool ◽  
Arctic Siberia

Abstract. Lakes act as important sinks for inorganic and organic sediment components. However, investigations of sedimentary carbon budgets within glacial lakes are currently absent from Arctic Siberia. The aim of this paper is to provide the first reconstruction of accumulation rates, sediment and carbon budgets from a lacustrine sediment core from Lake Rauchuagytgyn, Chukotka (Arctic Siberia). We combined multiple sediment biogeochemical and sedimentological parameters from a radiocarbon-dated 6.5 m sediment core with lake basin hydroacoustic data to derive sediment stratigraphy, sediment volumes and infill budgets. Our results distinguished three principal sediment and carbon accumulation regimes that could be identified across all measured environmental proxies including early Marine Isotope Stage 2 (MIS2) (ca. 29–23.4 ka cal BP), mid-MIS2–early MIS1 (ca. 23.4–11.69 ka cal BP) and the Holocene (ca. 11.69–present). Estimated organic carbon accumulation rates (OCARs) were higher within Holocene sediments (average 3.53 g OC m−2 a−1) than Pleistocene sediments (average 1.08 g OC m−2 a−1) and are similar to those calculated for boreal lakes from Quebec and Finland and Lake Baikal but significantly lower than Siberian thermokarst lakes and Alberta glacial lakes. Using a bootstrapping approach, we estimated the total organic carbon pool to be 0.26 ± 0.02 Mt and a total sediment pool of 25.7 ± 1.71 Mt within a hydroacoustically derived sediment volume of ca. 32 990 557 m3. The total organic carbon pool is substantially smaller than Alaskan yedoma, thermokarst lake sediments and Alberta glacial lakes but shares similarities with Finnish boreal lakes. Temporal variability in sediment and carbon accumulation dynamics at Lake Rauchuagytgyn is controlled predominantly by palaeoclimate variation that regulates lake ice-cover dynamics and catchment glacial, fluvial and permafrost processes through time. These processes, in turn, affect catchment and within-lake primary productivity as well as catchment soil development. Spatial differences compared to other lake systems at a trans-regional scale likely relate to the high-latitude, mountainous location of Lake Rauchuagytgyn.

scholarly journals The temperature sensitivity of organic matter decay in tidal marshes

2014 ◽  
Vol 11 (4) ◽  
pp. 6019-6037 ◽  
Author(s):  
M. L. Kirwan ◽  
G. R. Guntenspergen ◽  
J. A. Langley
Keyword(s):  
Organic Matter ◽  
Sea Level Rise ◽  
Sea Level ◽  
Temperature Sensitivity ◽  
Carbon Accumulation ◽  
Tidal Marshes ◽  
Moderate Increase ◽  
Elevated Atmospheric Co2 ◽  
Matter Production ◽  
Soil Elevation

Abstract. Approximately half of marine carbon sequestration takes place in coastal wetlands, including tidal marshes, where ecosystems accumulate organic matter to build soil elevation and survive sea level rise. The long-term viability of marshes, and their carbon pools, depends in part on how the balance between productivity and decay responds to climate change. Here, we report the sensitivity of soil organic matter decay in tidal marshes to seasonal and latitudinal variations in temperature measured over a 3 year period. We find a moderate increase in decay rate at warmer temperatures (3–6% °C−1, Q10 = 1.3–1.5). Despite the profound differences between microbial metabolism in wetlands and uplands, our results indicate a strong conservation of temperature sensitivity. Moreover, simple comparisons with organic matter production suggest that elevated atmospheric CO2 and warmer temperatures will accelerate carbon accumulation in marsh soils, and enhance their ability to survive sea level rise.

scholarly journals Lagoon Biogeochemical Processing is Reflected in Spatial Patterns of Sediment Stable Isotopic Ratios

2020 ◽  
Vol 8 (11) ◽  
pp. 874
Author(s):  
Elizabeth Burke Watson ◽  
Alejandro Hinojosa-Corona ◽  
Johannes R. Krause ◽  
Juan Carlos Herguera ◽  
Julianna McDonnell ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Spatial Patterns ◽  
Nitrogen Isotopes ◽  
Carbon Accumulation ◽  
Isotopic Ratios ◽  
Spatial Gradients ◽  
Seagrass Meadows ◽  
The Pacific ◽  
Stable Isotopic ◽  
Sediment Carbon

The spatial analysis of biota, particulate organic matter, and sediments for stable isotopes of carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) have proved useful for identifying patterns in productivity, nutrient pollution, and relationships between biological and physiochemical variables at the local and global scales. Yet such approaches are rarely applied to studies of lagoon or estuarine metabolism. Focusing on Bahía San Quintín, a heterotrophic seagrass-dominated lagoon on the Pacific coast of Baja California, México, we report on spatial patterns in surficial sediment CNS stable isotopic ratios as tracers of lagoon biogeochemical function. Stable nitrogen isotopes highlighted potential spatial variability in the balance between denitrification and nitrogen-fixation within the lagoon and identified an association between elevated δ15N levels and oyster culture, suggesting that oyster presence may be enhancing N2 production. Spatial patterns in δ34S covaried with sediment particle size, underlining the importance of sediment texture in determining the depth of sub-oxic-anoxic redox zones. Sediment carbon stable isotope ratios highlighted the lack of incorporation of seagrass carbon into seagrass meadow sediments, thus emphasizing the importance of phytoplankton or microphytobenthos for carbon accumulation in seagrass meadows. This report highlights the value of sediment isotopic values in corroborating spatial patterns in estuarine metabolism or macronutrient processing identified from chamber or flux-based studies. Stable isotope mapping can provide a useful addition to assessment of estuarine metabolism, or act as a stand-alone tool for generating hypotheses, identifying the influence of spatial gradients, and/or suggesting prime locations for investigation of microbial abundance or function.

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