  Cedrus libani (A. Rich) distribution in Lebanon: Past, present and future; François, Louis  ; et alin Comptes Rendus Biologies (2010), 333 Long-term vegetation studies are needed to better predict the impact of future climate change on vegetation structure and distribution. According to the IPCC scenario, the Mediterranean region is expected ... [more ▼] Long-term vegetation studies are needed to better predict the impact of future climate change on vegetation structure and distribution. According to the IPCC scenario, the Mediterranean region is expected to undergo significant climatic variability over the course of this century. Cedrus libani (A. Rich), in particular, is currently distributed in limited areas in the Eastern Mediterranean region, which are expected to be affected by such climate change. In order to predict the impact of future global warming, we have used fossil pollen data andmodel simulations. Palaeobotanical data show that C. libani has been affected by both climate change and human activities. Populations of C. libani survived in refugial zones when climatic conditions were less favourable and its range extended during periods of more suitable climate conditions. Simulations of its future geographical distribution for the year 2100 using a dynamic vegetation model show that only three areas from Mount Lebanon may allow its survival. These results extrapolated for cedar forests for the entire Eastern Mediterranean region show that forests in Syria are also threatened by future global warming. In southern Turkey, cedar forests seem to be less threatened. These results are expected to help in the long-term conservation of cedar forests in the Near East. [less ▲] Detailed reference viewed: 55 (3 ULg)Anatomical and biochemical changes during adventitious rooting of apple rootstocks MM 106 cultured in vitro.; ; et al in Comptes Rendus Biologies (2008), 331(7), 518-25 Adventitious rooting in microcuttings of Malus rootstocks MM106 was studied as regards their histological and biochemical aspects. Microcuttings from shoots raised in Murashige and Skoog's (1962) medium ... [more ▼] Adventitious rooting in microcuttings of Malus rootstocks MM106 was studied as regards their histological and biochemical aspects. Microcuttings from shoots raised in Murashige and Skoog's (1962) medium were transferred into a rooting medium containing IBA in the dark, then fixed 0, 3, 5, 7 and 10 days after. Some cambial zone and adjacent phloem cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed at day 3. Meristemoids became individualized, consisting of densely staining cells (with enlarged nucleoli) formed outside the xylem by day 5. Identifiable root primordia with a conical shape and several cell layers were present at day 7. Roots with organized tissue system emerged from the stem 10 days after the root induction treatment. From these histological observations, it can be established that the rooting induction stage ended before day 3. The initiation stage, with the first histological modifications to the formation of meristemoids, would correspond to the transient increase of our biochemical marker (peroxidase activity) until day 5. The best rooting percentage obtained with cultures in the presence of auxin during 5 days confirms this hypothesis. The expression of rooting can then take place. [less ▲] Detailed reference viewed: 44 (4 ULg)Does sulfide detoxication occur in the gills of the hydrothermal vent shrimp, Rimicaris exoculata?Compère, Philippe ; ; et alin Comptes Rendus Biologies (2002), 325 Detailed reference viewed: 7 (0 ULg)Controle hormonal du comportement et de la croissance testiculaire chez la caille coturnix corturnix japonicaBalthazart, Jacques ; in Comptes Rendus Biologies (1977), 171(3), 656-63 Detailed reference viewed: 8 (1 ULg) |
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