Changes in carbon isotope discrimination in grain cereals from different regions of the western Mediterranean Basin during the past seven millennia. Palaeoenvironmental evidence of a differential change in aridity during the late Holocene

1997 ◽  
Vol 3 (2) ◽  
pp. 107-118 ◽  
Author(s):  
J.L. ARAUS ◽  
A. FEBRERO ◽  
R. BUXO ◽  
M.D. CAMALICH ◽  
D. MARTIN ◽  
...  
1993 ◽  
Vol 20 (1) ◽  
pp. 117 ◽  
Author(s):  
JL Araus ◽  
R Buxo

Carbon isotope discrimination (Δ) was determined for kernels of six-row barley and durum wheat cultivated in the north-western Mediterranean basin during the last seven millennia. Samples from the Neolithic, Bronze, Iron and Middle Ages came from different archaeological sites in Catalonia. Samples for the period 1910-20 and 1990 were also analysed. There was a slight decrease (P=0.10, carbonisation-corrected values) in Δ from the Neolithic to the Iron Age period and a much steeper decrease from the Middle Ages to 1910-20 (P<0.01). Since water-use efficiency and isotope discrimination are negatively correlated, from the pattern of change in Δ it is suggested that there has been a progressive increase in the water-use efficiency (WUE) of these cereals. Since the Middle Ages this has coincided with increases in atmospheric CO2 concentration. Thus, for a given relative humidity and air temperature, the estimated WUE (measured as the ratio of CO2 assimilation to transpiration) from the Neolithic to the Middle Ages samples ranged between 65-70% of present time WUE values, whereas WUE for 1910-20 was about 86% of present values.


Ocean Science ◽  
2014 ◽  
Vol 10 (4) ◽  
pp. 693-700 ◽  
Author(s):  
M. Borghini ◽  
H. Bryden ◽  
K. Schroeder ◽  
S. Sparnocchia ◽  
A. Vetrano

Abstract. The deep waters of the western Mediterranean Sea have become saltier and warmer for at least the past 40 years at rates of about 0.015 and 0.04 °C per decade. Here we show that two processes contribute to these increases in temperature and salinity. On interannual timescales, deep water formation events in severe winters transmit increasingly salty intermediate waters into the deep water. The second process is a steady downward flux of heat and salt associated with salt finger mixing down through the halocline–thermocline that connects the Levantine Intermediate Water with the deep water. We illustrate these two processes with observations from repeat surveys of the western Mediterranean basin we have made over the past 10 years.


2014 ◽  
Vol 11 (1) ◽  
pp. 735-752 ◽  
Author(s):  
M. Borghini ◽  
H. Bryden ◽  
K. Schroeder ◽  
S. Sparnocchia ◽  
A. Vetrano

Abstract. The deep waters of the Mediterranean Sea have been getting saltier and warmer for at least the past 40 yr at rates of about 0.015 and 0.04 °C per decade. Here we show that two processes contribute to these increases in temperature and salinity. On interannual time scales, deep water formation events in severe winters transmit increasingly salty intermediate waters into the deep water. The second process is a steady downward flux of heat and salt through the halocline-thermocline that connects the Levantine Intermediate Water with the deep water. We illustrate these two processes with observations from repeat surveys of the western Mediterranean basin we have made over the past 10 yr.


2001 ◽  
Vol 65 (6) ◽  
pp. 537-548 ◽  
Author(s):  
M. P. GIRALDO ◽  
E. ESTEBAN ◽  
M. P. ALUJA ◽  
R. M. NOGUES ◽  
CH. BACKES-DURO ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 678
Author(s):  
Kamel Atrouz ◽  
Ratiba Bousba ◽  
Francesco Paolo Marra ◽  
Annalisa Marchese ◽  
Francesca Luisa Conforti ◽  
...  

Olive tree with its main final product, olive oil, is an important element of Mediterranean history, considered the emblematic fruit of a civilization. Despite its wide diffusion and economic and cultural importance, its evolutionary and phylogenetic history is still difficult to clarify. As part of the Mediterranean basin, Algeria was indicated as a secondary diversification center. However, genetic characterization studies from Maghreb area, are currently underrepresented. In this context, we characterized 119 endemic Algerian accessions by using 12 microsatellite markers with the main goal to evaluate the genetic diversity and population structure. In order to provide new insights about the history of olive diversification events in the Central-Western Mediterranean basin, we included and analyzed a sample of 103 Italian accessions from Sicily and, a set of molecular profiles of cultivars from the Central-Western Mediterranean area. The phylogenetic investigation let us to evaluate genetic relationships among Central-Mediterranean basin olive germplasm, highlight new synonymy cases to support the importance of vegetative propagation in the cultivated olive diffusion and consolidate the hypothesis of more recent admixture events occurrence. This work provided new information about Algerian germplasm biodiversity and contributed to clarify olive diversification process.


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