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Changes in pigment concentration and composition in Norway spruce induced by long-term exposure to low levels of ozone.
1995
Mikkelsen T.N. | Dodell B. | Lutz C.
Inorganic carbon utilization of tropical calcifying macroalgae and the impacts of intensive mariculture-derived coastal acidification on the physiological performance of the rhodolith Sporolithon sp
2020
Narvarte, Bienson Ceasar V. | Nelson, W. A. (Wendy A.) | Roleda, Michael Y.
Fish farming in coastal areas has become an important source of food to support the world’s increasing population. However, intensive and unregulated mariculture activities have contributed to changing seawater carbonate chemistry through the production of high levels of respiratory CO₂. This additional CO₂, i.e. in addition to atmospheric inputs, intensifies the effects of global ocean acidification resulting in localized extreme low pH levels. Marine calcifying macroalgae are susceptible to such changes due to their CaCO₃ skeleton. Their physiological response to CO₂-driven acidification is dependent on their carbon physiology. In this study, we used the pH drift experiment to determine the capability of 9 calcifying macroalgae to use one or more inorganic carbon (Cᵢ) species. From the 9 species, we selected the rhodolith Sporolithon sp. as a model organism to investigate the long-term effects of extreme low pH on the physiology and biochemistry of calcifying macroalgae. Samples were incubated under two pH treatments (pH 7.9 = ambient and pH 7.5 = extreme acidification) in a temperature-controlled (26 ± 0.02 °C) room provided with saturating light intensity (98.3 ± 2.50 μmol photons m⁻² s⁻¹). After the experimental treatment period (40 d), growth rate, calcification rate, nutrient uptake rate, organic content, skeletal CO₃⁻², pigments, and tissue C, N and P of Sporolithon samples were compared. The pH drift experiment revealed species-specific Cᵢ use mechanisms, even between congenerics, among tropical calcifying macroalgae. Furthermore, long-term extreme low pH significantly reduced the growth rate, calcification rate and skeletal CO₃⁻² content by 79%, 66% and 18%, respectively. On the other hand, nutrient uptake rates, organic matter, pigments and tissue C, N and P were not affected by the low pH treatments. Our results suggest that the rhodolith Sporolithon sp. is susceptible to the negative effects of extreme low pH resulting from intensive mariculture-driven coastal acidification.
Afficher plus [+] Moins [-]Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield
2013
Kumari, Sumita | Agrawal, Madhoolika | Tiwari, Supriya
The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO2 and O3, alone and in combination. As compared to the plants grown in charcoal filtered air (ACO2), growth and yield of the plants increased under elevated CO2 (ECO2) and decreased under combination of ECO2 with elevated O3 (ECO2 + EO3), ambient O3 (ACO2 + AO3) and elevated O3 (EO3). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO3. Foliar starch and organic carbon contents increased under ECO2 and ECO2 + EO3 and reduced under EO3 and ACO2 + AO3. Foliar N content declined in all treatments compared to ACO2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO2 is not enough to counteract O3 impact, but elevated CO2 has potential to counteract the negative effects of future O3 level.
Afficher plus [+] Moins [-]The effects of sodium erythorbate and ethylenediurea on photosynthetic function of ozone-exposed loblolly pine seedlings
1999
Kuehler, E.A. | Flagler, R.B. (Department of Forest Science, Texas Agriculture and Mechanical University, College Station, TX 77843 (USA))
Effects of ultraviolet-B radiation (UV-B) on growth and physiology of the dune grassland species Calamagrostis epigeios
1995
Tosserams, M. | Rozema, J. (Department of Ecology and Ecotoxicology, Faculty of Biology, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands))
Seasonal variation of gas exchange and pigmentation in branches of three grafted clones of mature ponderosa pine exposed to ozone and acid rain
1997
Anderson, P.D. | Houpis, J.L.J. | Helms, J.A. | Momen, B. (USDA Forest Service, Forestry Sciences Laboratory, Rhinelander, Wisconsin (USA))
Vicia faba as a bioindicator of oil pollution
1996
Malallah, G. | Afzal, M. | Gulshan, S. | Abraham, D. | Kurian, M. | Dhami, M.S.I. (Department of Botany and Microbiology, Faculty of Science, Kuwait University, Safat (Kuwait))
Chlorophyll, carotenoids and the activity of the xanthophyll cycle
1990
Siefermann-Harms, D. (Kernforschungszentrum Karlsruhe, Institut fur Genetik und fur Toxikologie von Spaltstoffen, Postfach 3640, W-7500 Karlsruhe 1 (Germany))
Pigment changes in Norway spruce induced by dust pollution
1997
Mandre, M. (Estonian Academy of Sciences, Tallinn (Estonia). Dept. of Ecophysiology) | Tuulmets, L.
Direct Effects of Air Pollution on Physiology of Forest Trees in the Western United States
1993
Bytnerowicz, A. (USDA Forest Service, Riverside, CA (USA). Pacific Southwest Research Station)
Physiological processes of western trees are effected by ozone at concentration over 80 ppb, depending on the duration of the exposures and environmental conditions. At a single fascicle level short-term ozone exposures can cause reduction, no change or increase of stomatal conductance and net assimilation rate. Two seasons of exposures at twice level ozone concentrations caused a significant reduction of stomatal conductance and pigment concentrations in foliage.
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