scholarly journals First-order estimate of the planktic foraminifer biomass in the modern ocean

2012 ◽  
Vol 4 (1) ◽  
pp. 75-89 ◽  
Author(s):  
R. Schiebel ◽  
A. Movellan
Keyword(s):  
Water Depth ◽  
Marine Ecosystem ◽  
Regional Scale ◽  
Global Scale ◽  
Order Estimate ◽  
Planktic Foraminifera ◽  
First Order ◽  
The North ◽  
Carbon Biomass ◽  
Wide Range

Abstract. Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. With a new non-destructive protocol developed from the bicinchoninic acid (BCA) method and nano-photospectrometry, we have analysed the protein-biomass, along with test size and weight, of 754 individual planktic foraminifers from 21 different species and morphotypes. From additional CHN analysis, it can be assumed that protein-biomass equals carbon-biomass. Accordingly, the average individual planktic foraminifer protein- and carbon-biomass amounts to 0.845 μg. Samples include symbiont bearing and symbiont-barren species from the sea surface down to 2500 m water depth. Conversion factors between individual biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum test diameter). Assemblage-biomass data presented here include 1128 sites and water depth intervals. The regional coverage of data includes the North Atlantic, Arabian Sea, Red Sea, and Caribbean as well as literature data from the eastern and western North Pacific, and covers a wide range of oligotrophic to eutrophic waters over six orders of magnitude of planktic-foraminifer assemblage-biomass (PFAB). A first order estimate of the average global planktic foraminifer biomass production (>125 μm) ranges from 8.2–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1), and might be more than three times as high including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first estimate of regional PFAB extrapolated to the global scale, and future estimates based on larger data sets might considerably deviate from the one presented here. This paper is supported by, and a contribution to the Marine Ecosystem Data project (MAREDAT). Data are available from http://www.pangaea.de (http://doi.pangaea.de/10.1594/PANGAEA.777386).

scholarly journals First-order estimate of the planktic foraminifer biomass in the modern global oceans

2012 ◽  
Vol 5 (1) ◽  
pp. 243-280
Author(s):  
R. Schiebel ◽  
A. Movellan
Keyword(s):  
Water Depth ◽  
Marine Ecosystem ◽  
Regional Scale ◽  
Global Scale ◽  
Order Estimate ◽  
Minimum Diameter ◽  
First Order ◽  
The North ◽  
Wide Range ◽  
Standing Stocks

Abstract. Planktic foraminifera are heterotrophic mesozooplankton of global marine abundance. The position of planktic foraminifers in the marine food web is different compared to other protozoans and ranges above the base of heterotrophic consumers. Being secondary producers with an omnivorous diet, which ranges from algae to small metazoans, planktic foraminifers are not limited to a single food source, and are assumed to occur at a balanced abundance displaying the overall marine biological productivity at a regional scale. We have calculated the assemblage carbon biomass from data on standing stocks between the sea surface and 2500 m water depth, based on 754 protein-biomass data of 21 planktic foraminifer species and morphotypes, produced with a newly developed method to analyze the protein biomass of single planktic foraminifer specimens. Samples include symbiont bearing and symbiont barren species, characteristic of surface and deep-water habitats. Conversion factors between individual protein-biomass and assemblage-biomass are calculated for test sizes between 72 and 845 μm (minimum diameter). The calculated assemblage biomass data presented here include 1057 sites and water depth intervals. Although the regional coverage of database is limited to the North Atlantic, Arabian Sea, Red Sea, and Caribbean, our data include a wide range of oligotrophic to eutrophic waters covering six orders of magnitude of assemblage biomass. A first order estimate of the global planktic foraminifer biomass from average standing stocks (>125 μm) ranges at 8.5–32.7 Tg C yr−1 (i.e. 0.008–0.033 Gt C yr−1), and might be more than three time as high including the entire fauna including neanic and juvenile individuals adding up to 25–100 Tg C yr−1. However, this is a first estimate of regional planktic-foraminifer assemblage-biomass (PFAB) extrapolated to the global scale, and future estimates based on larger data-sets might considerably deviate from the one presented here. This paper is supported by, and a contribution to the Marine Ecosystem Data project (MAREDAT). Data are available from www.pangaea.de (http://doi.pangaea.de/10.1594/PANGAEA.777386).

Uncovering the Canning Basin: a new comprehensive SEEBASE® model

2018 ◽  
Vol 58 (2) ◽  
pp. 793
Author(s):  
Karen Connors ◽  
Cedric Jorand ◽  
Peter Haines ◽  
Yijie Zhan ◽  
Lynn Pryer
Keyword(s):  
Western Australia ◽  
Potential Field ◽  
Field Data ◽  
Regional Scale ◽  
Structural Evolution ◽  
Potential Field Data ◽  
Canning Basin ◽  
The North ◽  
Wide Range ◽  
Order Of Magnitude

A new regional scale SEEBASE® model has been produced for the intracratonic Canning Basin, located in the north of Western Australia. The 2017 Canning Basin SEEBASE model is more than an order of magnitude higher resolution than the 2005 OZ SEEBASE version — the average resolution is ~1 : 1 M scale with higher resolution in areas of shallow basement with 2D seismic coverage — such as the Broome Platform and Barbwire Terrace. Post-2005 acquisition of potential field, seismic and well data in the Canning Basin by the Geological Survey of Western Australia (GSWA), Geoscience Australia and industry provided an excellent opportunity to upgrade the SEEBASE depth-to-basement model in 2017. The SEEBASE methodology focuses on a regional understanding of basement, using potential field data to interpret basement terranes, depth-to-basement (SEEBASE), regional structural geology and basement composition. The project involved extensive potential field processing and enhancement and compilation of a wide range of datasets. Integrated interpretation of the potential field data with seismic and well analysis has proven quite powerful and illustrates the strong basement control on the extent and location of basin elements. The project has reassessed the structural evolution of the basin, identified and mapped major structures and produced fault-event maps for key tectonic events. In addition, interpretative maps of basement terranes, depth-to-Moho, basement thickness, basement composition and total sediment thickness have been used to calculate a basin-wide map of basement-derived heat flow. The 2017 Canning Basin SEEBASE is the first public update of the widely used 2005 OZ SEEBASE. All the data and interpretations are available from the GSWA as a report and integrated ArcGIS project, which together provide an excellent summary of the key features within the Canning Basin that will aid hydrocarbon and mineral explorers in the region.

scholarly journals What is the P value of Siberian soils? Soil phosphorus status in south-western Siberia and comparison with a global data set

2016 ◽  
Vol 13 (8) ◽  
pp. 2493-2509 ◽  
Author(s):  
Félix Brédoire ◽  
Mark R. Bakker ◽  
Laurent Augusto ◽  
Pavel A. Barsukov ◽  
Delphine Derrien ◽  
...  
Keyword(s):  
Agricultural Development ◽  
Western Siberia ◽  
Regional Scale ◽  
Global Scale ◽  
Available P ◽  
Northern Eurasia ◽  
Data Set ◽  
Slow Kinetics ◽  
Wide Range ◽  
Plant Available P

Abstract. Climate change is particularly strong in northern Eurasia and substantial ecological changes are expected in this extensive region. The reshaping and migration northwards of bioclimatic zones may offer opportunities for agricultural development in western and central Siberia. However, the bioclimatic vegetation models currently employed for projections still do not consider soil fertility, in spite of this being highly critical for plant growth. In the present study, we surveyed the phosphorus (P) status in the south-west of Siberia where soils have developed on loess parent material. We selected six sites differing in pedoclimatic conditions and the soil was sampled at different depths down to 1 m in aspen (Populus tremula L.) forest as well as in grassland areas. The P status was assessed by conventional methods and by isotope dilution kinetics. We found that P concentrations and stocks, as well as their distribution through the soil profile, were fairly homogeneous on the regional scale studied, although there were some differences between sites (particularly in organic P). The young age of the soils, together with slow kinetics of soil formation processes have probably not yet resulted in a sufficiently wide range of soil physico-chemical conditions to observe a more diverging P status. The comparison of our data set with similar vegetation contexts on the global scale revealed that the soils of south-western Siberia, and more generally of northern Eurasia, often have (very) high levels of total, organic and inorganic P. The amount of plant-available P in topsoils, estimated by the isotopically exchangeable phosphate ions, was not particularly high but was intermediate on the global scale. However, large stocks of plant-available P are stored in subsurface layers which currently have low fine-root exploration intensities. These results suggest that the P resource is unlikely to constrain vegetation growth and agricultural development under the present conditions or in the near future.

Cross-border megasequence stratigraphy of the Northern, Central and Southern North Sea: a comparative tectono-stratigraphic synthesis

2021 ◽  
pp. SP494-2020-228
Author(s):  
Stefano Patruno ◽  
Henk Kombrink ◽  
Stuart G. Archer
Keyword(s):  
North Sea ◽  
Regional Scale ◽  
Foreland Basin ◽  
First Order ◽  
Cross Border ◽  
Southern North Sea ◽  
The North ◽  
Lithostratigraphic Units ◽  
The North Sea ◽  
Basin Fill

AbstractThe Devonian-Recent tectono-stratigraphic history of the Northern, Central and Southern North Sea is here reviewed at a regional scale and four novel cross-border pseudo-Wheeler diagrams are presented to summarize the stratigraphic evolution of the cycles of basin fill and uplift/erosion. In this scheme, six first-order megasequence boundaries have been defined, characterized by extensive and long-lasting erosional hiatuses and major coastal regressions: (1) Caledonian (or Base Devonian) Unconformity; (2) Variscan-Saalian (or Base Permian) Unconformity; (3) Mid Cimmerian (or Intra-Aalenian) Unconformity; (4) Late Cimmerian (or Base Cretaceous) Unconformity; (5) Atlantean (or Near-Base Tertiary) Unconformity; (6) Eridanos (or Mid-Miocene) Unconformity. These surfaces have been linked to regional causal factors ranging from: orogenesis-related compressional uplifts, in either active plate margin settings (1) or foreland basin settings (2); intra-plate dynamically supported uplifts associated with the development of mantle plumes (3, 5 and 6); the end-of-rifting and associated widespread erosion of tilted fault block crests (4).The aforementioned megasequence boundaries punctuate the geodynamic evolution of the North Sea area and facilitate the sub-division of the entire the North Sea sedimentary basin fill into six megasequences, named here from A to F. All the lithostratigraphic units of the North Sea (formations and members) have been described within the context of this first-order tectono-stratigraphic framework. The correlation power of certain stratigraphic markers are also compared and contrasted, together with the potential cross-border equivalence of sedimentary units on different sides of the political median lines.

Seasonal forecast of agricultural impacts of droughts in Mexico through a principal component regression based approach

2020 ◽  
Author(s):  
Roberto Real-Rangel ◽  
Adrián Pedrozo-Acuña ◽  
Agustín Breña-Naranjo
Keyword(s):  
Soil Moisture ◽  
Regional Scale ◽  
Principal Component Regression ◽  
Principal Component ◽  
Drought Monitoring ◽  
Drought Forecasting ◽  
Moisture Index ◽  
The North ◽  
Wide Range ◽  
Monitoring And Forecasting

<p>Drought monitoring and forecasting allows to adopt mitigating actions in early stages of an event to reduce the vulnerability of a wide range of environmetal, economical and social sectors. In Mexico, various drought monitoring systems on national and regional scale perform a follow up of these events, such as the Drought Monitor in Mexico, and the North American Drought Monitor, but seasonal drought forecasting is still a pending task. This study aims at fill this gap applying a methodology that uses data derived from a globally available atmospheric reanalysis product and a principal component regression based model oriented to predict drought impacts in rainfed crops associated to deficits in the soil moisture, estimated by means of the standardized soil moisture index (SSI). Using the state of Guanajuato (Center-North of Mexico) as a study case, the model generated yielded RSME values of 0.74 using regional and global hydrological, climatic and atmospheric variables as predictors with a lead-time of 4 months.</p>

scholarly journals Air–water CO<sub>2</sub> evasion from US East Coast estuaries

2017 ◽  
Vol 14 (9) ◽  
pp. 2441-2468 ◽  
Author(s):  
Goulven Gildas Laruelle ◽  
Nicolas Goossens ◽  
Sandra Arndt ◽  
Wei-Jun Cai ◽  
Pierre Regnier
Keyword(s):  
East Coast ◽  
Regional Scale ◽  
Global Scale ◽  
Biogeochemical Processes ◽  
Wide Range ◽  
Tidal Estuaries ◽  
Net Heterotrophy ◽  
Carbon Processing ◽  
Year 2000 ◽  
Us East Coast

Abstract. This study presents the first regional-scale assessment of estuarine CO2 evasion along the US East Coast (25–45° N). The focus is on 42 tidal estuaries, which together drain a catchment of 697 000 km2 or 76 % of the total area within this latitudinal band. The approach is based on the Carbon–Generic Estuary Model (C-GEM) that allows the simulation of hydrodynamics, transport, and biogeochemistry for a wide range of estuarine systems using readily available geometric parameters and global databases of seasonal climatic, hydraulic, and riverine biogeochemical information. Our simulations, performed using conditions representative of the year 2000, suggest that, together, US East Coast estuaries emit 1.9 Tg C yr−1 in the form of CO2, which corresponds to about 40 % of the carbon inputs from rivers, marshes, and mangroves. Carbon removal within estuaries results from a combination of physical (outgassing of supersaturated riverine waters) and biogeochemical processes (net heterotrophy and nitrification). The CO2 evasion and its underlying drivers show important variations across individual systems, but reveal a clear latitudinal pattern characterized by a decrease in the relative importance of physical over biogeochemical processes along a north–south gradient. Finally, the results reveal that the ratio of estuarine surface area to the river discharge, S∕Q (which has a scale of per meter discharged water per year), could be used as a predictor of the estuarine carbon processing in future regional- and global-scale assessments.

CO2 generation by calcified invertebrates along rocky shores of Brittany, France

2013 ◽  
Vol 64 (2) ◽  
pp. 91 ◽  
Author(s):  
Christian Hily ◽  
Jacques Grall ◽  
Laurent Chauvaud ◽  
Morgane Lejart ◽  
Jacques Clavier
Keyword(s):  
Intertidal Zone ◽  
Rocky Shore ◽  
Regional Scale ◽  
Coastal Environment ◽  
Co2 Production ◽  
Rocky Shores ◽  
Atlantic Region ◽  
The North ◽  
Wide Range ◽  
North Eastern

Many autochthonous and alien macroinvertebrates of the intertidal zone are biocalcifiers, and the present study proposes a first assessment of their calcimass and their annual calcium carbonate (CaCO3) production at a regional scale, along 500 km of the coastline of Brittany, France, which represents a wide range of the rocky-shore habitats commonly encountered in the north-eastern Atlantic region. All sites considered together gave a mean calcimass estimate of 5327 g m–2. The corresponding mean CaCO3 gross production was 2584 g m–2 year–1. The net production (including dissolution) by biocalcification was 2384 g CaCO3 m–2 year–1. Estimations of CO2 production via both calcification and respiration were carried out in particular for the phylum Mollusca and for crustacean barnacles, dominating in terms of calcimass. Mean CO2 production obtained by summing CO2 fluxes related to net CaCO3 production and respiration for all sampled sites was 22.9 mol m–2 year–1. These results illustrate the significance of CO2 production during biogenic CaCO3 precipitation of intertidal invertebrates in such temperate coastal environment compared with tropical zones and the contribution of the shelves to the global CaCO3 budget.

scholarly journals Planktic foraminiferal response to an early Paleocene transient warming event and biostratigraphic implications

2021 ◽  
Author(s):  
André Bornemann ◽  
Sofie Jehle ◽  
Friederike Lägel ◽  
Arne Deprez ◽  
Maria Rose Petrizzo ◽  
...  
Keyword(s):  
Time Scales ◽  
Environmental Changes ◽  
Global Scale ◽  
Global Changes ◽  
Calcareous Nannofossils ◽  
Planktic Foraminifera ◽  
Orbital Parameters ◽  
The North ◽  
Long Run ◽  
Early Paleocene

AbstractThe Latest Danian Event (LDE, ~ 62.2 Ma) is characterized by global changes in the carbon cycle as indicated by two negative δ13C excursions of up to ~ 1‰. These δ13C shifts are accompanied by a 2–3 °C warming of both surface and deep waters based on benthic and planktic foraminiferal δ18O measurements, and the LDE has, thus, been considered as a so-called hyperthermal event. The event lasted for 200 kyr and has been identified in various ocean basins and shallow marine settings. Here, we present a compilation of data from three deep-sea cores covering the Pacific, North and South Atlantic oceans as well as a southern Tethyan shelf section to document the response of planktic foraminifera assemblages to ocean warming. In all studied successions, we observe the disappearance of the planktic foraminifer genus Praemurica on a global scale that took place close to the onset of the LDE. Moreover, on the long run, praemuricids were contemporaneously replaced by morozovellids. Both the decline of Praemurica and a temperature increase started between 200 and 260 kyr before the LDE onset and were punctuated by the LDE itself. In this paper, we propose two mechanisms that have controlled the environmental changes associated with this event, (1) increased activity of the North Atlantic Igneous Province acting on long time-scales, and (2) changes of orbital parameters resulting in insolation changes on shorter time-scales.In contrast to a proposed muted benthic foraminiferal response, the planktic community has been substantially impacted by the LDE as indicated by changes in planktic foraminifera faunas and calcareous nannofossils. Finally, our quantitative and conventional approaches identifying stratigraphically important planktic foraminifera datum levels justify a revision of the upper Danian to lower Selandian planktic foraminifera biozonation.

scholarly journals Quaternary basaltic volcanic fields of the American Southwest

Geosphere ◽  
2021 ◽  
Author(s):  
Greg A. Valentine ◽  
Michael H. Ort ◽  
Joaquín A. Cortés
Keyword(s):  
Regional Scale ◽  
Plate Boundary ◽  
Poisson Model ◽  
Volcanic Field ◽  
American Southwest ◽  
Order Estimate ◽  
Recurrence Rates ◽  
Data Set ◽  
The North ◽  
Volcanic Fields

The southwestern United States contains numerous monogenetic basaltic volcanoes distributed in intraplate volcanic fields. We review, on a regional scale, our current understanding of the Quaternary basalts with a focus on aspects pertinent to hazard assessment, such as physical volcanology and geochronology, while also summarizing the several petrogenetic concep­tual models that have been proposed for the range of local tectonic settings in the region. We count 2229 volcanoes in 37 volcanic fields (including the Pinacate volcanic field, which is mostly in northern Sonora, Mexico). Volcanic landforms are dominantly scoria cones and ramparts with attendant lava fields that have a spectrum of ‘a’ā and blocky to pāhoehoe morphologies, while a small percentage of the volcanoes are maars and tuff cones. Explosive eruption styles that were driven mainly by magmatic volatiles, where they have been studied in detail, included Hawaiian, Strombolian, violent Strombolian, and sub-Plinian activity. The latter two have resulted in sub­stantial fallout deposits that can be traced tens of kilometers from source vents. Phreatomagmatic styles have produced pyroclastic current (mainly pyroclastic surges), ballistic, and fallout deposits. These eruption styles pose hazards to humans when they occur in populated areas and to air travel and regional infrastructure even in sparsely populated areas. All but one of the major volcanic fields (fields that contain ~100 or more Quaternary volcanoes) together form a northwest-southeast–trending band, which we suggest may reflect an influence of plate-boundary-related shearing on melt segregation in the upper mantle along with other factors; this view is consistent with recent global positioning system (GPS) and structural geologic data indicating the influence of dextral motion along the North America-Pacific plate boundary deep inside the Southwest. Of the 2229 Quaternary volcanoes identified, ~548 (25%) have been dated, and only ~15% have been dated with methods such as 40Ar/39Ar and cosmogenic surface exposure methods that are considered optimal for young basalts. Acknowledging the large uncertainty due to the poor geochronological data coverage, we use a simple Poisson model to pro­vide a first-order estimate of recurrence rates of monogenetic volcanoes on the scale of the region as a whole; recurrence rates using our compiled age data set range from 3.74 × 10−4 yr−1 to 8.63 × 10−4 yr−1. These values are only based on dated and mapped volcanoes, respectively, and do not account for undated and buried volcanoes or other uncertainties in the volcano count. The time between monogenetic eruptions in the Southwest is similar to the repose times of some polygenetic volcanoes, which suggests that the regional hazard is potentially commensurate with the hazard from a reawakening stratovolcano such as those in the Cascade Range. Notable in our review is that only a few volcanoes have been the subject of physical volcanological characterization, interpretation, and detailed petrologic study that may elu­cidate factors such as magma generation, ascent (including time scales), and controls on eruption style.

scholarly journals What is the P value of Siberian soils?

2015 ◽  
Vol 12 (23) ◽  
pp. 19819-19859 ◽  
Author(s):  
F. Brédoire ◽  
M. R. Bakker ◽  
L. Augusto ◽  
P. A. Barsukov ◽  
D. Derrien ◽  
...  
Keyword(s):  
Regional Scale ◽  
Global Scale ◽  
Parent Material ◽  
Available P ◽  
Northern Eurasia ◽  
P Value ◽  
Slow Kinetics ◽  
Wide Range ◽  
Agriculture Development ◽  
Plant Available P

Abstract. Climate change is particularly strong in Northern Eurasia and substantial ecological changes are expected in this wide region. The reshaping and the migration northward of bioclimatic zones may offer opportunities for agriculture development in western and central Siberia. However, the bioclimatic vegetation models currently employed for projections still do not consider soil fertility whereas it is highly critical for plant growth. In the present study, we surveyed the phosphorus (P) status in the south-west of Siberia where soils are developed on loess parent material. We selected six sites differing by pedoclimate conditions and sampled the soil at different depths down to one meter in aspen (Populus tremula L.) forest as well as in grassland areas. The P status was assessed by conventional methods and by isotope dilution kinetics. We found that P concentrations and stocks, as well as their distribution through the soil profile, were rather homogeneous at the studied regional scale, although there were some differences among sites (particularly in organic P). The young age of the soils, together with slow kinetics of soil forming processes, have probably not yet conducted to a sufficiently wide range of soil physico-chemical conditions to observe more diverging P status. The comparison of our dataset to similar vegetation contexts on the global scale revealed that the soils of south-western Siberia, and more generally of Northern Eurasia, has often (very) high levels of total, organic and inorganic P. The amount of plant-available P in topsoils, estimated by the isotopically exchangeable phosphate ions, was not particularly high, but intermediate at the global scale. However, large stocks of plant-available P are stored in subsurface layers which have currently low fine root exploration intensities. These results suggest that the P resource is unlikely to constrain vegetation growth and agriculture development in the present and near future conditions.

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