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.

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.

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).

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.

scholarly journals Forest Soil Colloids Enhance Delivery of Phosphorus Into a Diffusive Gradient in Thin Films (DGT) Sink

2021 ◽  
Vol 3 ◽  
Author(s):  
Alexander Konrad ◽  
Benjamin Billiy ◽  
Philipp Regenbogen ◽  
Roland Bol ◽  
Friederike Lang ◽  
...  
Keyword(s):  
Thin Films ◽  
P Uptake ◽  
Parent Material ◽  
Plant Roots ◽  
Bulk Soil ◽  
Available P ◽  
Soil Extraction ◽  
Soil P ◽  
Freeze Dried ◽  
Plant Available P

Phosphorus (P) is preferentially bound to colloids in soil. On the one hand, colloids may facilitate soil P leaching leading to a decrease of plant available P, but on the other hand they can carry P to plant roots, thus supporting the P uptake of plants. We tested the magnitude and the kinetics of P delivery by colloids into a P sink mimicking plant roots using the Diffusive Gradients in Thin-Films (DGT) technique. Colloids were extracted with water from three forest soils differing in parent material using a method based on dispersion and sedimentation. Freeze-dried colloids, the respective bulk soil, and the colloid-free extraction residue were sterilized and mixed with quartz sand and silt to an equal P basis. The mixtures were wetted and the diffusive fluxes of P into the DGTs were measured under sterile, water unsaturated conditions. The colloids extracted from a P-poor sandy podzolic soil were highly enriched in iron and organic matter compared to the bulk soil and delivered more P at a higher rate into the sink compared to bulk soil and the colloid-free soil extraction residue. However, colloidal P delivery into the sink was smaller than P release and transport from the bulk soil developed on dolomite rock, and with no difference for a soil with intermediate phosphorus-stocks developed from gneiss. Our results provide evidence that both the mobility of colloids and their P binding strength control their contribution to the plant available P-pool of soils. Overall, our findings highlight the relevance of colloids for P delivery to plant roots.

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).

Are local losses of biodiversity causing degraded ecosystem function?

2017 ◽  
Author(s):  
Mark Vellend
Keyword(s):  
Ecosystem Function ◽  
Species Interactions ◽  
Regional Scale ◽  
Temporal Trends ◽  
Biodiversity Loss ◽  
Large Degree ◽  
Global Scale ◽  
Degraded Ecosystem ◽  
Biodiversity Change ◽  
Local Extirpation

This chapter highlights the scale dependence of biodiversity change over time and its consequences for arguments about the instrumental value of biodiversity. While biodiversity is in decline on a global scale, the temporal trends on regional and local scales include cases of biodiversity increase, no change, and decline. Environmental change, anthropogenic or otherwise, causes both local extirpation and colonization of species, and thus turnover in species composition, but not necessarily declines in biodiversity. In some situations, such as plants at the regional scale, human-mediated colonizations have greatly outnumbered extinctions, thus causing a marked increase in species richness. Since the potential influence of biodiversity on ecosystem function and services is mediated to a large degree by local or neighborhood species interactions, these results challenge the generality of the argument that biodiversity loss is putting at risk the ecosystem service benefits people receive from nature.

scholarly journals Natural Experiment on Trade and Investment Liberalization and Soft Drink Consumption

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
Y Tcholakov
Keyword(s):  
Public Health ◽  
International Trade ◽  
Natural Experiment ◽  
Soft Drink ◽  
Trade Agreement ◽  
P Value ◽  
Soft Drink Consumption ◽  
Obesity And Diabetes ◽  
Wide Range ◽  
The Impact

Abstract Background Globalization is recognized to as a contributing factor to a health harming environment through a variety of mechanisms including through changes in food systems and food availability. Sugar-sweetened beverage (SSB) consumption is linked to obesity and diabetes and its regulation is a key priority for public health. The Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) is an international trade agreement between 11 countries. Methods This project uses of natural experiment methods to predict the impact of the entry into force of the CPTPP on SSB consumption. These methods allow quantitative inferences to be drawn in the situations where the exposure is not randomly assigned. Soft drink consumption data was collected from the Euromonitor database for 80 countries from all regions. This data was used to estimate the effect of agreements similar to the TPP. Results Eleven country trade agreement pairs were identified. In 5 cases out of the 11, the exposed country had a higher soft drink consumption at five years after the trade agreement. The effect of the trade agreement exposure for an average country in the sample in a trade agreement was found to be 1.10 (95% CI: 1.01-1.18; p-value: 0.03) after adjusting for GDP and the involvement of the US. In 7 of the 11 member-countries soft drink consumption is expected to increase yielding an average increase of 9.0% in those countries; the changes did not yield statistically significant differences in others. Conclusions This projected extended the use of synthetic methods to the projection of future effects of policy implementation. While it showed that there may be increasing trend of SSB consumption in certain scenarios, this could not be generalized to all cases. This illustrates the wide range of effects of international trade liberalization and highlights that national policy probably plays a strong modulating role on the impact that it has on local food environments. Key messages Globalization can lead to health harming environments and its impacts should further be studied by public health professionals and researchers. Many global policies have the potential to lead to significant health impacts but are negotiated without involving public health experts.

P–530 The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
L Girardi ◽  
M Serdaroğulları ◽  
C Patassini ◽  
S Caroselli ◽  
M Costa ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
False Negative ◽  
Cell Mass ◽  
Categorical Variables ◽  
P Value ◽  
Sequencing Data ◽  
Preimplantation Genetic Testing ◽  
Exact Test ◽  
Institutional Review ◽  
Wide Range

Abstract Study question What is the effect of varying diagnostic thresholds on the accuracy of Next Generation Sequencing (NGS)-based preimplantation genetic testing for aneuploidies (PGT-A)? Summary answer When single trophectoderm biopsies are tested, the employment of 80% upper threshold increases mosaic calls and false negative aneuploidy results compared to more stringent thresholds. What is known already Trophectoderm (TE) biopsy coupled with NGS-based PGT-A technologies are able to accurately predict Inner Cell Mass’ (ICM) constitution when uniform whole chromosome aneuploidies are considered. However, minor technical and biological inconsistencies in NGS procedures and biopsy specimens can result in subtle variability in analytical results. In this context, the stringency of thresholds employed for diagnostic calls can lead to incorrect classification of uniformly aneuploid embryos into the mosaic category, ultimately affecting PGT-A accuracy. In this study, we evaluated the diagnostic predictivity of different aneuploidy classification criteria by employing blinded analysis of chromosome copy number values (CNV) in multifocal blastocyst biopsies. Study design, size, duration The accuracy of different aneuploidy diagnostic cut-offs was assessed comparing chromosomal CNV in intra-blastocysts multifocal biopsies. Enrolled embryos were donated for research between June and September 2020. The Institutional Review Board at the Near East University approved the study (project: YDU/20l9/70–849). Embryos diagnosed with uniform chromosomal alterations (single or multiple) in their clinical TE biopsy (n = 27) were disaggregated into 5 portions: the ICM and 4 TE biopsies. Overall, 135 specimens were collected and analysed. Participants/materials, setting, methods Twenty-seven donated blastocysts were warmed and disaggregated in TE biopsies and ICM (n = 135 biopsies). PGT-A analysis was performed using Ion ReproSeq PGS kit and Ion S5 sequencer (ThermoFisher). Sequencing data were blindly analysed with Ion-Reporter software. Intra-blastocyst comparison of raw NGS data was performed employing different thresholds commonly used for aneuploidy classification. CNV for each chromosome were reported as aneuploid according to 70% or 80% thresholds. Categorical variables were compared using Fisher’s exact test. Main results and the role of chance In this study, a total of 50 aneuploid patterns in 27 disaggregated embryos were explored. Single TE biopsy results were considered as true positive when they displayed the same alteration detected in the ICM at levels above the 70% or 80% thresholds. Alternatively, alterations detected in the euploid or mosaic range were considered as false negative aneuploidy results. When the 70% threshold was applied, aneuploidy findings were confirmed in 94.5% of TE biopsies analyzed (n = 189/200; 95%CI=90.37–37.22), while 5.5% showed a mosaic profile (50–70%) but uniformly abnormal ICM. Positive (PPV) and negative predictive value (NPV) per chromosome were 100.0% (n = 189/189; 95%CI=98.07–100.00) and 99.5% (n = 2192/2203; 95%CI=99.11–99.75) respectively. When the upper cut-off was experimentally placed at 80% of abnormal cells, a significant decrease (p-value=0.0097) in the percentage of confirmed aneuploid calls was observed (86.5%; n = 173/200; 95%CI=80.97–90.91), resulting in mosaicism overcalling, especially in the high range (50–80%). Less stringent thresholds led to extremely high PPV (100.0%; n = 173/173; 95%CI=97.89–100.00), while NPV decreased to 98.8% (n = 2192/2219; 95%CI=98.30–99.23). Furthermore, no additional true mosaic patterns were identified with the use of wide range thresholds for aneuploidy classification. Limitations, reasons for caution This approach involved the analysis of aneuploidy CNV thresholds at the embryo level and lacked from genotyping-based confirmation analysis. Moreover, aneuploid embryos with known meiotic partial deletion/duplication were not included. Wider implications of the findings: The use of wide thresholds for detecting intermediate chromosomal CNV up to 80% doesn’t improve PGT-A ability to discriminate true mosaic from uniformly aneuploid embryos, lowering overall diagnostic accuracy. Hence, a proportion of the embryos diagnosed as mosaic using wide calling thresholds may actually be uniformly aneuploid and inadvertently transferred. Trial registration number N/A

scholarly journals Assessment of model estimates of land-atmosphere CO<sub>2</sub> exchange across Northern Eurasia

2015 ◽  
Vol 12 (14) ◽  
pp. 4385-4405 ◽  
Author(s):  
M. A. Rawlins ◽  
A. D. McGuire ◽  
J. S. Kimball ◽  
P. Dass ◽  
D. Lawrence ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Carbon ◽  
Residence Time ◽  
Primary Productivity ◽  
Ecosystem Respiration ◽  
Regional Scale ◽  
Northern Eurasia ◽  
Sink Strength ◽  
Vegetation Productivity ◽  
Co2 Sink

Abstract. A warming climate is altering land-atmosphere exchanges of carbon, with a potential for increased vegetation productivity as well as the mobilization of permafrost soil carbon stores. Here we investigate land-atmosphere carbon dioxide (CO2) cycling through analysis of net ecosystem productivity (NEP) and its component fluxes of gross primary productivity (GPP) and ecosystem respiration (ER) and soil carbon residence time, simulated by a set of land surface models (LSMs) over a region spanning the drainage basin of Northern Eurasia. The retrospective simulations cover the period 1960–2009 at 0.5° resolution, which is a scale common among many global carbon and climate model simulations. Model performance benchmarks were drawn from comparisons against both observed CO2 fluxes derived from site-based eddy covariance measurements as well as regional-scale GPP estimates based on satellite remote-sensing data. The site-based comparisons depict a tendency for overestimates in GPP and ER for several of the models, particularly at the two sites to the south. For several models the spatial pattern in GPP explains less than half the variance in the MODIS MOD17 GPP product. Across the models NEP increases by as little as 0.01 to as much as 0.79 g C m−2 yr−2, equivalent to 3 to 340 % of the respective model means, over the analysis period. For the multimodel average the increase is 135 % of the mean from the first to last 10 years of record (1960–1969 vs. 2000–2009), with a weakening CO2 sink over the latter decades. Vegetation net primary productivity increased by 8 to 30 % from the first to last 10 years, contributing to soil carbon storage gains. The range in regional mean NEP among the group is twice the multimodel mean, indicative of the uncertainty in CO2 sink strength. The models simulate that inputs to the soil carbon pool exceeded losses, resulting in a net soil carbon gain amid a decrease in residence time. Our analysis points to improvements in model elements controlling vegetation productivity and soil respiration as being needed for reducing uncertainty in land-atmosphere CO2 exchange. These advances will require collection of new field data on vegetation and soil dynamics, the development of benchmarking data sets from measurements and remote-sensing observations, and investments in future model development and intercomparison studies.

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