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[Effect of surface liming in doses suitable for melioration on the pH-value and cation exchange of an acid brown soil on loess]
1989
Meiwes, K.J. (Niedersaechsische Forstliche Versuchsanstalt, Goettingen (Germany, F.R.)) | Beese, F.
Seawater carbonate chemistry and copepod Centropages tenuiremis feeding, filtering and respiration rate during experiments, 2012 Texto completo
2012
Li, Wei | Gao, Kunshan
Seawater carbonate chemistry and copepod Centropages tenuiremis feeding, filtering and respiration rate during experiments, 2012 Texto completo
2012
Li, Wei | Gao, Kunshan
Climate change mediates marine chemical and physical environments and therefore influences marine organisms. While increasing atmospheric CO2 level and associated ocean acidification has been predicted to stimulate marine primary productivity and may affect community structure, the processes that impact food chain and biological CO2 pump are less documented. We hypothesized that copepods, as the secondary marine producer, may respond to future changes in seawater carbonate chemistry associated with ocean acidification due to increasing atmospheric CO2 concentration. Here, we show that the copepod, Centropages tenuiremis, was able to perceive the chemical changes in seawater induced under elevated CO2 concentration (>1700 µatm, pH < 7.60) with avoidance strategy. The copepod's respiration increased at the elevated CO2 (1000 µatm), associated acidity (pH 7.83) and its feeding rates also increased correspondingly, except for the initial acclimating period, when it fed less. Our results imply that marine secondary producers increase their respiration and feeding rate in response to ocean acidification to balance the energy cost against increased acidity and CO2 concentration.
Mostrar más [+] Menos [-]A marine secondary producer respires and feeds more in a high CO₂ ocean Texto completo
2012
Li, Wei | Gao, Kunshan
Climate change mediates marine chemical and physical environments and therefore influences marine organisms. While increasing atmospheric CO₂ level and associated ocean acidification has been predicted to stimulate marine primary productivity and may affect community structure, the processes that impact food chain and biological CO₂ pump are less documented. We hypothesized that copepods, as the secondary marine producer, may respond to future changes in seawater carbonate chemistry associated with ocean acidification due to increasing atmospheric CO₂ concentration. Here, we show that the copepod, Centropages tenuiremis, was able to perceive the chemical changes in seawater induced under elevated CO₂ concentration (>1700μatm, pH<7.60) with avoidance strategy. The copepod’s respiration increased at the elevated CO₂ (1000μatm), associated acidity (pH 7.83) and its feeding rates also increased correspondingly, except for the initial acclimating period, when it fed less. Our results imply that marine secondary producers increase their respiration and feeding rate in response to ocean acidification to balance the energy cost against increased acidity and CO₂ concentration.
Mostrar más [+] Menos [-]Biological impacts of enhanced alkalinity in Carcinus maenas Texto completo
2013
Cripps, Gemma | Widdicombe, Stephen | Spicer, John I | Findlay, Helen S
Further steps are needed to establish feasible alleviation strategies that are able to reduce the impacts of ocean acidification, whilst ensuring minimal biological side-effects in the process. Whilst there is a growing body of literature on the biological impacts of many other carbon dioxide reduction techniques, seemingly little is known about enhanced alkalinity. For this reason, we investigated the potential physiological impacts of using chemical sequestration as an alleviation strategy. In a controlled experiment, Carcinus maenas were acutely exposed to concentrations of Ca(OH)2 that would be required to reverse the decline in ocean surface pH and return it to pre-industrial levels. Acute exposure significantly affected all individuals' acid-base balance resulting in slight respiratory alkalosis and hyperkalemia, which was strongest in mature females. Although the trigger for both of these responses is currently unclear, this study has shown that alkalinity addition does alter acid-base balance in this comparatively robust crustacean species.
Mostrar más [+] Menos [-][Anthropogenic changes of forest ecosystems. History - present - future]
1987
Ulrich, B. (Goettingen Univ. (Germany, F.R.). Inst. fuer Waldernaehrung)
Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations Texto completo
2016
Jin, Peng | Gao, Kunshan
Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations Texto completo
2016
Jin, Peng | Gao, Kunshan
Ocean acidification (OA), induced by rapid anthropogenic CO2 rise and its dissolution in seawater, is known to have consequences for marine organisms. However, knowledge on the evolutionary responses of phytoplankton to OA has been poorly studied. Here we examined the coccolithophore Gephyrocapsa oceanica, while growing it for 2000 generations under ambient and elevated CO2 levels. While OA stimulated growth in the earlier selection period (from generations 700 to 1550), it reduced it in the later selection period up to 2000 generations. Similarly, stimulated production of particulate organic carbon and nitrogen reduced with increasing selection period and decreased under OA up to 2000 generations. The specific adaptation of growth to OA disappeared in generations 1700 to 2000 when compared with that at 1000 generations. Both phenotypic plasticity and fitness decreased within selection time, suggesting that the species' resilience to OA decreased after 2000 generations under high CO2 selection.
Mostrar más [+] Menos [-]Reduced resilience of a globally distributed coccolithophore to ocean acidification: Confirmed up to 2000 generations Texto completo
2016
Jin, Peng | Gao, Kunshan
Ocean acidification (OA), induced by rapid anthropogenic CO2 rise and its dissolution in seawater, is known to have consequences for marine organisms. However, knowledge on the evolutionary responses of phytoplankton to OA has been poorly studied. Here we examined the coccolithophore Gephyrocapsa oceanica, while growing it for 2000 generations under ambient and elevated CO2 levels. While OA stimulated growth in the earlier selection period (from generations ~700 to ~1550), it reduced it in the later selection period up to 2000 generations. Similarly, stimulated production of particulate organic carbon and nitrogen reduced with increasing selection period and decreased under OA up to 2000 generations. The specific adaptation of growth to OA disappeared in generations 1700 to 2000 when compared with that at 1000 generations. Both phenotypic plasticity and fitness decreased within selection time, suggesting that the species' resilience to OA decreased after 2000 generations under high CO2 selection.
Mostrar más [+] Menos [-]Seawater carbonate chemistry and biological processes of zooplankton Amphiascoides atopus and Schizopera knabeni during experiments, 2010 Texto completo
2010
Pascal, Pierre-Yves | Fleeger, J W | Galvez, Fernando | Carman, Kevin R
Increased atmospheric CO2 concentrations are causing greater dissolution of CO2 into seawater, and are ultimately responsible for today's ongoing ocean acidification. We manipulated seawater acidity by addition of HCl and by increasing CO2 concentration and observed that two coastal harpacticoid copepods, Amphiascoides atopus and Schizopera knabeni were both more sensitive to increased acidity when generated by CO2. The present study indicates that copepods living in environments more prone to hypercapnia, such as mudflats where S. knabeni lives, may be less sensitive to future acidification. Ocean acidification is also expected to alter the toxicity of waterborne metals by influencing their speciation in seawater. CO2 enrichment did not affect the free-ion concentration of Cd but did increase the free-ion concentration of Cu. Antagonistic toxicities were observed between CO2 with Cd, Cu and Cu free-ion in A. atopus. This interaction could be due to a competition for H+ and metals for binding sites.
Mostrar más [+] Menos [-]Seawater carbonate chemistry and shell microstructure, mechanical properties of an edible estuarine oyster Texto completo
2019
Meng, Yuan | Guo, Zhenbin | Yao, Haimin | Yeung, Kelvin W K | Thiyagarajan, Vengatesen
Seawater carbonate chemistry and shell microstructure, mechanical properties of an edible estuarine oyster Texto completo
2019
Meng, Yuan | Guo, Zhenbin | Yao, Haimin | Yeung, Kelvin W K | Thiyagarajan, Vengatesen
Ocean acidification (OA) is well-known for impairing marine calcification; however, the end response of several essential species to this perturbation remains unknown. Decreased pH and saturation levels (Omega) of minerals under OA is projected to alter shell crystallography and thus to reduce shell mechanical properties. This study examined this hypothesis using a commercially important estuarine oyster Magallana hongkongensis. Although shell damage occurred on the outmost prismatic layer and the undying myostracum at decreased pH 7.6 and 7.3, the major foliated layer was relatively unharmed. Oysters maintained their shell hardness and stiffness through altered crystal unit orientation under pH 7.6 conditions. However, under the undersaturated conditions (Omega Cal ~ 0.8) at pH 7.3, the realigned crystal units in foliated layer ultimately resulted in less stiff shells which indicated although estuarine oysters are mechanically resistant to unfavorable calcification conditions, extremely low pH condition is still a threat to this essential species.
Mostrar más [+] Menos [-]Calcium carbonate unit realignment under acidification: A potential compensatory mechanism in an edible estuarine oyster Texto completo
2019
Meng, Yuan | Guo, Zhenbin | Yao, Haimin | Yeung, Kelvin W.K. | Thiyagarajan, V.
Ocean acidification (OA) is well-known for impairing marine calcification; however, the end response of several essential species to this perturbation remains unknown. Decreased pH and saturation levels (Ω) of minerals under OA is projected to alter shell crystallography and thus to reduce shell mechanical properties. This study examined this hypothesis using a commercially important estuarine oyster Magallana hongkongensis. Although shell damage occurred on the outmost prismatic layer and the undying myostracum at decreased pH 7.6 and 7.3, the major foliated layer was relatively unharmed. Oysters maintained their shell hardness and stiffness through altered crystal unit orientation under pH 7.6 conditions. However, under the undersaturated conditions (ΩCal ~ 0.8) at pH 7.3, the realigned crystal units in foliated layer ultimately resulted in less stiff shells which indicated although estuarine oysters are mechanically resistant to unfavorable calcification conditions, extremely low pH condition is still a threat to this essential species.
Mostrar más [+] Menos [-]Root and mycorrhizal development in healthy and declining Norway spruce stands
1989
Schneider, B.U. | Meyer, J. | Schulze, E.D. | Zech, W.
Leaching and uptake of ions through above-ground Norway spruce tree parts
1989
Klemm, O. | Kuhn, U. | Beck, E. | Katz, C. | Oren, R. | Schulze, E.D. | Steudle, E. | Mitterhuber, E. | Pfanz, H. | Kaiser, W.M. | Kaupenjohann, M. | Schneider, B.U. | Hantschel, R. | Horn, R. | Zech, W.
[Approach on the measurement- and experiment station in the forest (MEXFO) and presentation of first results]
1987
Thiele, V. (Landesanstalt fuer Immissionsschutz des Landes Nordrhein-Westfalen (LIS), Essen (Germany, F.R.)) | Specovius, J. | Metzger, F.