scholarly journals Response of the temperate coral <i>Cladocora caespitosa</i> to mid- and long-term exposure to <i>p</i>CO<sub>2</sub> and temperature levels projected in 2100

2009 ◽  
Vol 6 (4) ◽  
pp. 7103-7131 ◽  
Author(s):  
R. Rodolfo-Metalpa ◽  
S. Martin ◽  
C. Ferrier-Pagès ◽  
J.-P. Gattuso
Keyword(s):  
Slow Growth ◽  
High Pco2 ◽  
Saturation State ◽  
Co2 Partial Pressure ◽  
Cladocora Caespitosa ◽  
Temperate Coral ◽  
Predominant Factor ◽  
Temperature Levels ◽  
Temperate Corals

Abstract. Atmospheric CO2 partial pressure (pCO2) is expected to increase to 700 ppm or more by the end of the present century. Anthropogenic CO2 is absorbed by the oceans leading to decreases in pH and the CaCO3 saturation state (Ω) of the seawater. While pCO2 was shown to drastically decrease calcification rates in tropical, fast growing corals, here we show, using the Mediterranean symbiotic coral Cladocora caespitosa, that the conventional belief that an increase in pCO2, in the range predicted to 2100, reduces calcification rates may not be widespread in temperate corals. We found that the seasonal change in temperature was the predominant factor controlling the physiology and growth of C. caespitosa, while an increase in pCO2, alone or in combination with global warming, had no significant effect on photosynthesis, photosynthetic efficiency and calcification. This result differs from that obtained on reef-building corals, which exhibit lower rates of calcification at elevated pCO2. The lack of sensitivity of temperate corals to high-pCO2 levels might be due to its slow growth rates, which seem to be more dependent on temperature than on the saturation state of calcium carbonate in the range predicted for the end of the century.

scholarly journals Response of the temperate coral <i>Cladocora caespitosa</i> to mid- and long-term exposure to <i>p</i>CO<sub>2</sub> and temperature levels projected for the year 2100 AD

2010 ◽  
Vol 7 (1) ◽  
pp. 289-300 ◽  
Author(s):  
R. Rodolfo-Metalpa ◽  
S. Martin ◽  
C. Ferrier-Pagès ◽  
J.-P. Gattuso
Keyword(s):  
Slow Growth ◽  
Elevated Pco2 ◽  
Saturation State ◽  
Co2 Partial Pressure ◽  
Cladocora Caespitosa ◽  
Temperate Coral ◽  
Predominant Factor ◽  
Zooxanthellate Coral ◽  
Temperature Levels

Abstract. Atmospheric CO2 partial pressure (pCO2) is expected to increase to 700 μatm or more by the end of the present century. Anthropogenic CO2 is absorbed by the oceans, leading to decreases in pH and the CaCO3 saturation state (Ω) of the seawater. Elevated pCO2 was shown to drastically decrease calcification rates in tropical zooxanthellate corals. Here we show, using the Mediterranean zooxanthellate coral Cladocora caespitosa, that an increase in pCO2, in the range predicted for 2100, does not reduce its calcification rate. Therefore, the conventional belief that calcification rates will be affected by ocean acidification may not be widespread in temperate corals. Seasonal change in temperature is the predominant factor controlling photosynthesis, respiration, calcification and symbiont density. An increase in pCO2, alone or in combination with elevated temperature, had no significant effect on photosynthesis, photosynthetic efficiency and calcification. The lack of sensitivity C. caespitosa to elevated pCO2 might be due to its slow growth rates, which seem to be more dependent on temperature than on the saturation state of calcium carbonate in the range projected for the end of the century.

scholarly journals Response of benthic foraminifera to ocean acidification in their natural sediment environment: a long-term culturing experiment

2014 ◽  
Vol 11 (6) ◽  
pp. 1581-1597 ◽  
Author(s):  
K. Haynert ◽  
J. Schönfeld ◽  
R. Schiebel ◽  
B. Wilson ◽  
J. Thomsen
Keyword(s):  
Ocean Acidification ◽  
Experimental Period ◽  
Organic Content ◽  
High Pco2 ◽  
Natural Sediment ◽  
Size Frequency Distribution ◽  
Saturation State ◽  
Carbonate Production ◽  
Subdominant Species

Abstract. Calcifying foraminifera are expected to be endangered by ocean acidification; however, the response of a complete community kept in natural sediment and over multiple generations under controlled laboratory conditions has not been constrained to date. During 6 months of incubation, foraminiferal assemblages were kept and treated in natural sediment with pCO2-enriched seawater of 430, 907, 1865 and 3247 μatm pCO2. The fauna was dominated by Ammonia aomoriensis and Elphidium species, whereas agglutinated species were rare. After 6 months of incubation, pore water alkalinity was much higher in comparison to the overlying seawater. Consequently, the saturation state of Ωcalc was much higher in the sediment than in the water column in nearly all pCO2 treatments and remained close to saturation. As a result, the life cycle (population density, growth and reproduction) of living assemblages varied markedly during the experimental period, but was largely unaffected by the pCO2 treatments applied. According to the size–frequency distribution, we conclude that foraminifera start reproduction at a diameter of 250 μm. Mortality of living Ammonia aomoriensis was unaffected, whereas size of large and dead tests decreased with elevated pCO2 from 285 μm (pCO2 from 430 to 1865 μatm) to 258 μm (pCO2 3247 μatm). The total organic content of living Ammonia aomoriensis has been determined to be 4.3% of CaCO3 weight. Living individuals had a calcium carbonate production rate of 0.47 g m−2 a−1, whereas dead empty tests accumulated a rate of 0.27 g m−2 a−1. Although Ωcalc was close to 1, approximately 30% of the empty tests of Ammonia aomoriensis showed dissolution features at high pCO2 of 3247 μatm during the last 2 months of incubation. In contrast, tests of the subdominant species, Elphidium incertum, stayed intact. Our results emphasize that the sensitivity to ocean acidification of the endobenthic foraminifera Ammonia aomoriensis in their natural sediment habitat is much lower compared to the experimental response of specimens isolated from the sediment.

Geochemical Behaviour of Uranium in Sedimentary Formations: Insights From a Natural Analogue Study

2009 ◽  
Author(s):  
Ulrich Noseck ◽  
Vaclava Havlova ◽  
Juhani Suksi ◽  
Thomas Brasser ◽  
Radek Cervinka
Keyword(s):  
Current Knowledge ◽  
Natural Analogue ◽  
Near Surface ◽  
Co2 Partial Pressure ◽  
Long Term Stability ◽  
Reducing Conditions ◽  
Phosphate Mineral ◽  
Sedimentary System ◽  
The Impact

Groundwater data from the natural analogue site Ruprechtov have been evaluated with special emphasis on the uranium behaviour in the so-called uranium-rich clay/lignite horizon. In this horizon in-situ Eh-values in the range of −160 to −280 mV seem to be determined by the SO42−/HS− couple. Under these conditions U(IV) is expected to be the preferential redox state in solution. However, on-site measurements in groundwater from the clay/lignite horizon show only a fraction of about 20% occurring in the reduced state U(IV). Thermodynamic calculations reveal that the high CO2 partial pressure in the clay/lignite horizon can stabilise hexavalent uranium, which explains the occurrence of U(VI). The calculations also indicate that the low uranium concentrations in the range between 0.2 and 2.1μg/l are controlled by amorphous UO2 and/or the U(IV) phosphate mineral ningyoite. This confirms the findings from previous work that the uranium (IV) mineral phases are long-term stable under the reducing conditions in the clay/lignite horizon without any signatures for uranium mobilisation. It supports the current knowledge of the geological development of the site and is also another important indication for the long-term stability of the sedimentary system itself, namely of the reducing geochemical conditions in the near-surface (30m to 60 m deep) clay/lignite horizon. Further work with respect to the impact of changes in redox conditions on the uranium speciation is on the way.

scholarly journals Regional variation in green-up timing along a caribou migratory corridor: spatial associations with snowmelt and temperature

2020 ◽  
Author(s):  
Christian John ◽  
Douglas Miller ◽  
Eric S. Post
Keyword(s):  
Explanatory Power ◽  
Arctic Region ◽  
Spring Temperature ◽  
Migration Timing ◽  
Predominant Factor ◽  
Long Term Trends ◽  
Low Arctic ◽  
Resource Variability ◽  
Migratory Corridor

Spring green-up in Arctic and alpine systems is predominantly controlled by temperature and snowmelt timing preceding and during the growing season. Variation in the timing of green-up across space is an important aspect of resource variability with which mobile herbivores must contend. Here, we measure the explanatory power of abiotic drivers of green-up in a Low Arctic region of west Greenland, host to a migratory caribou population. We identify inconsistent relationships between green-up and abiotic drivers across space. While green-up timing is most closely related to snowmelt in some areas, in others it is most closely related to spring temperature. The negative correlation between the explanatory power of snowmelt and temperature suggests that at broad scales, where green-up is more constrained by snow cover, such as moist, mountainous coastal areas, it is less constrained by temperature. Where snow is less persistent through winter, such as cold, dry inland areas, temperature becomes the predominant factor driving green-up. If the principal driver of spring plant growth is inconsistent across a region, long-term trends in resource phenology could vary spatially. For seasonal migrants like caribou, synchronizing migration timing with resource phenology may be complicated by discordant interannual change across drivers of green-up timing.

scholarly journals Export of calcium carbonate corrosive waters from the East Siberian Sea

2016 ◽  
Author(s):  
Leif G. Anderson ◽  
Jörgen Ek ◽  
Ylva Ericson ◽  
Christoph Humborg ◽  
Igor Semiletov ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Sea Ice ◽  
North Atlantic Ocean ◽  
The Arctic ◽  
High Pco2 ◽  
Low Oxygen ◽  
Saturation State ◽  
Ice Melt ◽  
The North ◽  
Transformation Of Organic Matter

Abstract. The Siberian Shelf Seas are areas of extensive biogeochemical transformation of organic matter, both of marine and terrestrial origin. This in combination with brine production from sea ice formation results in a cold bottom water of relative high salinity and partial pressure of carbon dioxide (pCO2). Data from the SWERUS-C3 expedition compiled on the icebreaker Oden in July to September 2014 show the distribution of such waters at the outer shelf, as well as their export into the deep central Arctic basins. Very high pCO2 water, up to close to 1000 µatm, was observed associated with high nutrients and low oxygen concentrations. Consequently the saturation state of calcium carbonate was low, down to less than 0.8 for calcite and 0.5 for aragonite. Waters undersaturated in aragonite were also observed in the surface in waters at equilibrium with atmospheric CO2, however, at these conditions the cause of under-saturation was low salinity from river runoff and/or sea ice melt. The calcium carbonate corrosive water was observed all along the continental margin and well out into the deep Makarov and Canada Basins at a depth from about 50 m depth in the west to about 150 m in the east. These waters of low aragonite saturation state are traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean north of Greenland and in the western Fram Strait, thus potentially impacting the marine life in the North Atlantic Ocean.

scholarly journals INVEST ASI, EKSPOR DAN MASALAH DE-INDUSTRIALISASI DI INDONESIA

2017 ◽  
Vol 5 (2) ◽  
pp. 179
Author(s):  
Anton Agus Setyawan ◽  
Fatchurrohman Fatchurrohman
Keyword(s):  
Direct Investment ◽  
Econometric Model ◽  
Slow Growth ◽  
Policy Implications ◽  
Economic Recovery ◽  
Investment Climate ◽  
Short Term ◽  
Investment Rate ◽  
The Ideal

There are two constraints in the process of economic recovery in Indonesia. First, investment rate is decreasing in the last five years. This matter happens due to the bad investment climate in Indonesia. Second, slow growth of export rate in Indonesia. At the present, investment rate in Indonesia is only 22 percent of GDP, while the ideal rate is 30 percent of GDP. Another problem, which may be interrupting the economic recovery, is de-industrialization. The sign of de-industrialization occur by relocation phenomena of FDIfrom Indonesia. This research analyze the effects of direct investment and export to GDP. The tool of analyses of this research is econometric model known as Error Correc­tion Models. The results shows that in a long term and short term, export and direct investment do not have a significant effect to GDP. It shows that Indonesia do not have a clear policy about export and investment. The policy implications of this research are government should have a deregulation policy in the industry and recover investment climate.

scholarly journals Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

2021 ◽  
Vol 118 (3) ◽  
pp. e2004769118
Author(s):  
Elizabeth M. Bullard ◽  
Ivan Torres ◽  
Tianqi Ren ◽  
Olivia A. Graeve ◽  
Kaustuv Roy
Keyword(s):  
Ocean Acidification ◽  
Historical Data ◽  
Mineralogical Composition ◽  
Marine Species ◽  
Mytilus Californianus ◽  
Negative Effects ◽  
Saturation State ◽  
Long Term Changes ◽  
Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

scholarly journals Efficient long-term conservation of Taraxacum pieninicum synthetic seeds in slow growth conditions

2017 ◽  
Vol 132 (3) ◽  
pp. 469-478 ◽  
Author(s):  
Monika Kamińska ◽  
Marcin Gołębiewski ◽  
Andrzej Tretyn ◽  
Alina Trejgell
Keyword(s):  
Slow Growth ◽  
Growth Conditions ◽  
Synthetic Seeds ◽  
Taraxacum Pieninicum

Understanding the Long-Term Weed Community Dynamics in Organic and Conventional Crop Rotations Using the Principal Response Curve Method

Weed Science ◽  
2019 ◽  
Vol 67 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Dilshan Benaragama ◽  
Julia L. Leeson ◽  
Steve J. Shirtliffe
Keyword(s):  
Community Composition ◽  
Community Dynamics ◽  
Cropping Systems ◽  
High Input ◽  
Organic Systems ◽  
No Till ◽  
Principal Response Curve ◽  
Predominant Factor ◽  
Conventional Systems

AbstractWeeds have acquired evolutionary adaptations to the diverse crop and weed management strategies used in cropping systems. Therefore, changes in crop production practices such as conventional to organic systems, tillage-based to no-till systems, and diversity in crop rotations can result in differences in weed community composition that have management implications. A study was carried out to understand the weed community dynamics in a long-term alternative cropping systems study at Scott, SK, Canada. Long-term (18-yr) weed community composition data in wheat (Triticum aestivumL.) in ORG (organic), RED (reduced-input, no-till), and HIGH (high-input, conventional tillage) systems with three levels of crop rotation diversity, LOW (low diversity), DAG (diversified annual grains), and DAP (diversified annuals and perennials), were used to study the effect of different cropping systems and the effect of environment (random temporal effects) on residual weed community composition using the principal response curve (PRC) technique. The interaction between cropping systems and year-to-year random environmental changes was found to be the predominant factor causing fluctuations in weed community composition. Furthermore, the single most predominant factor influencing the weed composition was year-to-year random changes. Organic systems clearly differed from the two conventional systems in most years and had more diverse weed communities compared with the two conventional systems. The two conventional systems exhibited similar weed composition in most years. In this study, the use of the PRC method allowed capture of the real temporal dynamics reflected in the cropping systems by time interaction. This study further concludes that moving from a tillage-based, high-input conventional system to a no-till, reduced-input system did not cause significant changes in the weed community composition throughout the time period, but diversity in organic systems was high, probably due to increased occurrence of some difficult to control species.

Sign in / Sign up

Export Citation Format

Share Document