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Wyszukujesz frazę "δ13C" wg kryterium: Temat


Wyświetlanie 1-8 z 8
Tytuł:
Climatic sensitivity of delta13C in tree rings of Quercus robur L., Populus tremula L. and Pinus sylvestris L. in Vilnius region (eastern Lithuania)
Autorzy:
Barisevičiūtė, Rūta
Skipitytė, Raminta
Pukienė, Rutilė
Lapeikaitė, Indrė
Kakaras, Irmantas
Remeikis, Vidmantas
Powiązania:
https://bibliotekanauki.pl/articles/956802.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
δ13c
climate
tree-rings
dendroclimatology
Opis:
The aim of this work was to evaluate the possibilities of using carbon isotope measurements to determine a strong climate signal of trees influenced by the pollutant stress as well as to examine the difference in reaction of several investigated species to the climate change. Eurasian aspen (Populus tremula), pedunculate oak (Quercus robur) and Scots pine (Pinus sylvestris) trees from Vilnius region were selected for the stable carbon isotope analysis. Our results showed that over the last 70 years (1940–2009) the climate during summer months was the most important factor for the variation of stable carbon isotope values in tree rings, but its influence on different tree species slightly differed. δ13C measurements in Eurasian aspen best corresponded to the air temperature and the precipitation signal in July–August. Oak was more sensitive to the temperature and relative humidity in June–July. A positive correlation coefficient with temperature in the period of transition from the previous vegetation to dormancy season (previous September–October) was specific to oak as well. Scots pine grown at a polluted site was sensitive only to precipitation in summer months of the growing season. The correlation between δ13C measurements and climate data was determined to be from low to moderate in all the investigated trees and did not exceed the value of |r| ≥ 0.71 suggested by McCarroll et al. (2003) as a necessary value for the reliable climate reconstruction. However, the highest correlation coefficient values of 0.65 and 0.61, obtained between the maximal air temperature throughout the hydrological year (previous September–current August) and δ13C in oak rings or between mean monthly sunshine hours throughout July–August and δ13C values in aspen rings, respectively, are comparable with those used in many palaeoclimatic reconstructions that were based even on weaker correlations.
Źródło:
Dendrobiology; 2017, 78; 1-9
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Note on the stable isotope values of vein calcite in the El-Seboah peralkaline granite (SW Egypt)
Autorzy:
Hassan, Kamaleldin M.
Powiązania:
https://bibliotekanauki.pl/articles/2086490.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
δ13C
δ18O
carbonate-hosting veins
peralkaline granite
Egypt
Opis:
Stable isotope data for carbon (δ13C) and oxygen (δ18O) are used to constrain the environments of calcite formation in two veins in the El-Seboah peralkaline granite in south-western Egypt. Vein I with calcitemagnetite-goethite-hematite-quartz, and vein II with calcite-magnetite-goethite-kaolinite-hematite-quartz are texturally distinct. The calcite of each vein has characteristic δ13C- and δ18O-values: + 0.32 and -7.28‰ for vein I and + 1.16 and - 1.21‰ for vein II, respectively. The observed differences between the δ13C values of the two veins indicate that they represent two separate systems of primary dissolved inorganic carbon formed at or near equilibrium with atmospheric CO2. The δ18O values, on the other hand, indicate calcite deposition from meteoric waters which were fresh for vein I and brackish for vein II.
Źródło:
Mineralogia; 2011, 42, 2/3; 113--120
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Note on the stable isotope values of vein calcite in the El-Seboah peralkaline granite (SW Egypt)
Autorzy:
Hassan, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/2086543.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
δ13C
δ18O
carbonate-hosting veins
peralkaline granite
Egypt
Opis:
Stable isotope data for carbon (δ13C) and oxygen (δ18O) are used to constrain the environments of calcite formation in two veins in the El-Seboah peralkaline granite in south-western Egypt. Vein I with calcitemagnetite-goethite-hematite-quartz, and vein II with calcite-magnetite-goethite-kaolinite-hematite-quartz are texturally distinct. The calcite of each vein has characteristic δ13C- and δ18O-values: + 0.32 and -7.28‰ for vein I and + 1.16 and - 1.21‰ for vein II, respectively. The observed differences between the δ13C values of the two veins indicate that they represent two separate systems of primary dissolved inorganic carbon formed at or near equilibrium with atmospheric CO2. The δ18O values, on the other hand, indicate calcite deposition from meteoric waters which were fresh for vein I and brackish for vein II.
Źródło:
Mineralogia; 2011, 42, 2/3; 113--120
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional traits related to environmental divergence in combination with phylogenetic relationship of Picea species
Autorzy:
Wang, M.
Wang, J.
Zhang, A.
Zhang, X.
Sun, S.
Zhao, C.
Powiązania:
https://bibliotekanauki.pl/articles/2077949.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
δ13C
P50
Picea
seeva
quantitative convergence index
Opis:
Background: Plants have adapted to fine-scale environmental heterogeneity through ecologically important traits, leading to new lineages. This suggests that differentiation of important traits has been beneficial to habitat partitioning among closely related species. However, the pattern of ecological divergences and differentiation of functional traits in combination with phylogenetic relationships have not been widely examined. Material and methods: To illustrate the pattern of ecological divergences of nine Picea species, spatial evolutionary and ecological vicariance analysis (seeva) was used to quantify and test the divergence between sister lineages. Five functional traits were measured in a common garden experiment. For all traits the quantitative convergence index (QVI) was determined. Furthermore, their relationships with divergent environmental variables were analyzed in the context of phylogenetic relationships. Results: Temperature variables (maximum temperature of warmest month and temperature annual range) split at basal nodes and precipitation variables (annual precipitation and precipitation of driest quarter) split at terminal nodes. Conservative traits were leaf mass per area (LMA) and net photosynthetic rate (Pn), which reflected selective retention when ancestors suffered cold environmental separation. Meanwhile, linear stomatal density (LSD), carbon-13 isotope ratio (δ13C) and water potential at 50% loss of hydraulic conductivity (P50) were convergent between species, but only P50 exhibited adaption to different precipitation conditions. The nine Picea species exhibit a distinct environmental divergence pattern. LMA and Pn were selectively retained when their ancestors were subjected to cold environmental separation. P50 was an important trait with respect to adaptation to precipitation differences. This research provided a new way of expounding the correlation between environment, functional traits and phylogeny, deepening our understanding of environmental divergence, trait differentiation and speciation.
Źródło:
Dendrobiology; 2018, 80; 131-142
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxygen isotope analysis of shark teeth phosphates from Bartonian (Eocene) deposits in Mangyshlak peninsula, Kazakhstan
Autorzy:
Pelc, Andrzej
Hałas, Stanisław
Niedźwiedzki, Robert
Powiązania:
https://bibliotekanauki.pl/articles/2086485.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
Bartonian
carbonate
Mangyshlak peninsula
phosphate
shark teeth
δ18O
δ13C
Opis:
We report the results of high-precision (±0.05‰) oxygen isotope analysis of phosphates in 6 teeth of fossil sharks from the Mangyshlak peninsula. This precision was achieved by the offline preparation of CO2 which was then analyzed on a dual-inlet and triple-collector IRMS. The teeth samples were separated from Middle- and Late Bartonian sediments cropping out in two locations, Usak and Kuilus. Seawater temperatures calculated from the δ18O data vary from 23–41oC. However, these temperatures are probably overestimated due to freshwater inflow. The data point at higher temperature in the Late Bartonian than in the Middle Bartonian and suggest differences in the depth habitats of the shark species studied.
Źródło:
Mineralogia; 2011, 42, 1; 53--61
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxygen isotope analysis of shark teeth phosphates from Bartonian (Eocene) deposits in Mangyshlak peninsula, Kazakhstan
Autorzy:
Pelc, A.
Hałas, S.
Niedźwiedzki, R.
Powiązania:
https://bibliotekanauki.pl/articles/2086536.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
Bartonian
carbonate
Mangyshlak peninsula
phosphate
shark teeth
δ18O
δ13C
Opis:
We report the results of high-precision (±0.05‰) oxygen isotope analysis of phosphates in 6 teeth of fossil sharks from the Mangyshlak peninsula. This precision was achieved by the offline preparation of CO2 which was then analyzed on a dual-inlet and triple-collector IRMS. The teeth samples were separated from Middle- and Late Bartonian sediments cropping out in two locations, Usak and Kuilus. Seawater temperatures calculated from the δ18O data vary from 23–41oC. However, these temperatures are probably overestimated due to freshwater inflow. The data point at higher temperature in the Late Bartonian than in the Middle Bartonian and suggest differences in the depth habitats of the shark species studied.
Źródło:
Mineralogia; 2011, 42, 1; 53--61
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of sulphur and carbon stable-isotope composition of fish scales and muscles to identify the origin of fish
Autorzy:
Trembaczowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2086488.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
stable isotopes
δ34S
δ13C
fish scales
fish muscle
food web relations
Opis:
δ34S and δ13C analyses were used to determine the origin of trout specimens. The isotope record of their scales and muscles are compared with a database previously obtained from wild- and reared fish coming from Polish rivers and pond farms. The comparison made it possible to find out whether the trout were wild or reared.
Źródło:
Mineralogia; 2011, 42, 1; 33--37
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of sulphur and carbon stable-isotope composition of fish scales and muscles to identify the origin of fish
Autorzy:
Trembaczowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2086538.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
stable isotopes
δ34S
δ13C
fish scales
fish muscle
food web relations
Opis:
δ34S and δ13C analyses were used to determine the origin of trout specimens. The isotope record of their scales and muscles are compared with a database previously obtained from wild- and reared fish coming from Polish rivers and pond farms. The comparison made it possible to find out whether the trout were wild or reared.
Źródło:
Mineralogia; 2011, 42, 1; 33--37
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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