scholarly journals Carbon Isotopes of Riparian Forests Trees in the Savannas of the Volta Sub-Basin of Ghana Reveal Contrasting Responses to Climatic and Environmental Variations

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 251 ◽  
Author(s):  
Emmanuel Boakye ◽  
Aster Gebrekirstos ◽  
Dibi Hyppolite ◽  
Victor Barnes ◽  
Stefan Porembski ◽  
...  
Keyword(s):  
Climate Change ◽  
Stable Isotopes ◽  
Carbon Isotope ◽  
Tree Ring ◽  
Isotope Composition ◽  
Carbon Isotope Composition ◽  
Riparian Forests ◽  
Δ13c Values ◽  
Riparian Trees ◽  
Species Specific

Stable isotopes of tree rings are frequently used as proxies in climate change studies. However, species-specific relationships between climate and tree-ring stable isotopes have not yet been studied in riparian forests in the savannas of West Africa. Four cross-dated discs, each of Afzelia africana Sm. (evergreen) and Anogeissus leiocarpus (DC.) Guill. & Perr. (deciduous) in the humid (HSZ) and dry (DSZ) savanna zones of the Volta basin in Ghana were selected from a larger tree-ring dataset to assess the relationships between the tree-ring carbon isotope composition (δ13C values) and climatic parameters. The atmospherically corrected δ13C values of both studied species showed that A. africana was enriched in 13C compared to A. leiocarpus. Strong correlations were found between δ13C values of A. africana and A. leiocarpus with temperature, but weak correlations with precipitation. Spatial correlation analysis revealed significant relationships between δ13C values of both tree species and Sea Surface Temperatures in the Gulf of Guinea in the southern Atlantic Ocean. The results suggest that the carbon isotope composition of riparian trees in the Volta river basin has a potential to reconstruct climate variability and to assess tree ecological responses to climate change.

scholarly journals Stable Isotopes (H, C, S) and the Origin of Baltic Amber

2009 ◽  
Vol 33 (-1) ◽  
pp. 33-36 ◽  
Author(s):  
Algirdas Gaigalas ◽  
Stanislaw Halas
Keyword(s):  
Stable Isotopes ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Isotope Analysis ◽  
Carbon Isotope Composition ◽  
Baltic Amber ◽  
Light Elements ◽  
Subsequent Evolution

Stable Isotopes (H, C, S) and the Origin of Baltic Amber New results of isotope analysis of light elements (H, C and S) of a dozen Baltic amber samples are described and discussed. Carbon isotope composition was nearly constant (ca. -23‰), whereas sulphur and hydrogen varied in their isotope compositions from +4 to -28‰ and from -171 to -213‰, respectively. The formation and subsequent evolution of this material since its origin in Paleogene time until present is outlined.

TREE-RING WIDTH AND STABLE CARBON ISOTOPE COMPOSITION OF JAPANESE CYPRESS IN THE LAKE BIWA AREA, CENTRAL JAPAN, AND THEIR HYDROLOGIC AND CLIMATIC IMPLICATIONS

IAWA Journal ◽  
2009 ◽  
Vol 30 (4) ◽  
pp. 395-406 ◽  
Author(s):  
Kenjiro Sho ◽  
Hiroshi Aoki Takahashi ◽  
Hiroshi Miyai ◽  
Shuichi Ikebuchi ◽  
Toshio Nakamura
Keyword(s):  
Carbon Isotope ◽  
Tree Ring ◽  
Lake Biwa ◽  
Isotope Composition ◽  
Stable Carbon Isotope ◽  
Ring Width ◽  
Early Summer ◽  
Carbon Isotope Composition ◽  
Central Japan ◽  
Japanese Cypress

Chronologies of tree-ring width and stable carbon isotope composition of Japanese cypress were developed to help reconstruct a 300-year record of past hydrologic and climatic environments in the Lake Biwa area, central Japan. Site chronologies were built with 37 trees for ring width and four trees for carbon isotope composition, respectively. Correlation analysis with monthly climatic data revealed that radial growth of the trees is related to temperature in early spring, precipitation (or number of precipitation days) in early summer and precipitation in previous-year summer to autumn. Tree-ring cellulose carbon isotopic composition is correlated most significantly with the number of precipitation days in early summer months. Consequently, a chronology of the number of precipitation days in May was reconstructed by multiple regression analysis with ring-width and carbon-isotope predictors and was validated by comparison with the recent observed record.

scholarly journals Retrospective Analysis of Tree Decline Based on Intrinsic Water-Use Efficiency in Semi-Arid Areas of North China

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 577
Author(s):  
Weiwei Lu ◽  
Xinxiao Yu ◽  
Guodong Jia
Keyword(s):  
Climate Change ◽  
Tree Ring ◽  
Tree Growth ◽  
North China ◽  
Isotope Composition ◽  
Ring Width ◽  
Carbon Isotope Composition ◽  
Tree Decline ◽  
Tree Ring Width

Long-term tree growth is significantly affected by climate change, which have become a global concern. Tree-ring width and isotopic information can show how trees respond to climate change on a long-term scale and reveal some phenomena of tree decline or death. In this study, we used isotopic techniques and investigated annual changes in carbon isotope composition and tree-ring width of Populus simonii Carr. in Zhangbei, as well as trends in tree-ring carbon discrimination (Δ13C) and iWUE in normal, mildly declining and severely declining trees, in order to make a retrospective analysis and further understand the process of tree decline. We found that there were significant differences (p < 0.01 **) in δ13C, Δ13C, ci and iWUE at different decline stages, meaning that the δ13C and iWUE could be new indicators of tree health. The iWUE of all groups increased significantly, while the growth rate of declined P. simonii was much higher than that of normal growth P. simonii. According to the analysis, there may be a threshold of iWUE for healthy trees, which once the threshold value is exceeded, it indicates that trees are resistant to adversity and their growth is under stress. Similarly, the changing trend of BAI supports our conclusion with its changes showed that tree growth became slower and slower as degradation progressed. iWUE inferred from tree-ring stable carbon isotope composition is a strong modulator of adaptation capacity in response to environmental stressors under climate change. Elevated annual temperatures and increased groundwater depth are all contributing to the decline of P. simonii in north China.

scholarly journals Tree-ring density and carbon isotope composition are early-warning signals of drought-induced mortality in the drought tolerant Canary Island pine

2021 ◽  
Vol 310 ◽  
pp. 108634
Author(s):  
Rosana López ◽  
Francisco Javier Cano ◽  
Jesús Rodríguez-Calcerrada ◽  
Gabriel Sangüesa-Barreda ◽  
Antonio Gazol ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Tree Ring ◽  
Early Warning ◽  
Canary Island ◽  
Isotope Composition ◽  
Carbon Isotope Composition ◽  
Warning Signals ◽  
Early Warning Signals ◽  
Ring Density ◽  
Drought Tolerant

scholarly journals Methanogenesis during Shu’aiba diagenesis: examples from Al Shaheen Field, Block 5, offshore Qatar

GeoArabia ◽  
2007 ◽  
Vol 12 (1) ◽  
pp. 37-58 ◽  
Author(s):  
Madeleine J. Raven ◽  
Tony Dickson
Keyword(s):  
Oxygen Isotope ◽  
Carbon Isotope ◽  
Isotope Composition ◽  
Sedimentary Rocks ◽  
Carbon Isotope Composition ◽  
Bulk Rock ◽  
Δ13c Values ◽  
Isotope Stratigraphy ◽  
Calcite Cement ◽  
Insight Into

ABSTRACT Evidence has been found for the involvement of bacterial methanogenic processes in the diagenesis of late Early Aptian Shu’aiba Formation sedimentary rocks from Block 5, offshore Qatar. This is in the form of δ13C values significantly higher than the presumed late Early Aptian marine signal. High δ13C values were recorded in early-formed inclusion-rich calcite that represents neomorphosed aragonite/marine cement (+6.6‰) and the latest precipitated blocky non-ferroan calcite cement (+8.9‰). Oxygen-isotope data suggest that the later methanogenic episode occurred during burial. In bulk rock samples from another well, δ13C values of +6.5 to +11.5‰ were determined from a 10 ft thick zone located 4 ft below the top of the Shu’aiba. In other wells for which data were available the equivalent interval of the Shu’aiba was characterised by expected marine δ13C values. Finally, δ13C values up to +9.1‰ were recorded in a localised area of dolomite replacement immediately beneath the Top Shu’aiba surface, which can be dated to after the onset of Nahr Umr Formation deposition. These are the first reported examples of methanogenic reactions affecting the Shu’aiba Formation and provide new insight into the diagenesis of this formation, which is often assumed to be dominated by meteoric processes. The evidence presented for the resetting of the carbon-isotope composition of the bulk rock has implications for the application of carbon-isotope stratigraphy to the Shu’aiba Formation.

scholarly journals Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks

2010 ◽  
Vol 67 (7) ◽  
pp. 1425-1431 ◽  
Author(s):  
Ángel Guerra ◽  
Alejandro B. Rodríguez-Navarro ◽  
Ángel F. González ◽  
Chris S. Romanek ◽  
Pedro Álvarez-Lloret ◽  
...  
Keyword(s):  
Life History ◽  
Stable Isotope ◽  
Carbon Isotope ◽  
Life History Traits ◽  
Isotope Composition ◽  
Nitrogen Isotope ◽  
Carbon Isotope Composition ◽  
Δ13c Values ◽  
Giant Squid ◽  
Stable Isotope Signatures

Abstract Guerra, Á., Rodríguez-Navarro, A. B., González, Á. F., Romanek, C. S., Álvarez-Lloret, P., and Pierce, G. J. 2010. Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks. – ICES Journal of Marine Science, 67: 1425–1431. Carbon and nitrogen isotope profiles constructed from the upper beaks of four giant squid Architeuthis dux from the Bay of Biscay and Namibian waters provided a time-integrated record of their diet. Values of δ15N ranged from 5.5 to 13.4‰ and of δ13C from −14.4 to −17.8‰. Nitrogen isotope profiles differed significantly in shape among the four animals analysed, but δ15N increased along each profile, with lowest values around the rostral tip. The difference between the lowest and the highest δ15N values was ∼5.8‰, slightly less than a two-level difference between the trophic position of small and large A. dux. The increase in δ13C values was not as pronounced as for the δ15N profiles, but the changes suggest an ontogenetic shift in diet early in life from smaller prey of relatively low trophic status to larger prey of higher status. Fluctuations in δ13C values observed near the rostral tip may be associated with a greater intrinsic variability in the carbon isotope composition of relatively small prey, and/or transient migratory behaviour early in life. The relative stability of the δ13C profiles over the remainder of their lifespan is consistent with the hypothesis that adult giant squid inhabit relatively small, well-defined, and productive areas, where food resources have a constant carbon isotope composition.

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