Réponses adaptatives à un assèchement édaphique chez 3 provenances de chêne liège (Quercus suber)
2021
Abassi, Mejda | Zouaoui, Refka | Hachani, Chadlia | Béjaoui, Zoubeir
The effects of climate change induce the increase of extreme events such as drought in the Mediterranean region, accentuating the degradation of forest ecosystems of Quercus suber L. Seedlings of Q. suber (El Feija (EF), Ben Metir (BM), and Oued Zen (OZ)) from 3 Tunisian provenances were evaluated for their tolerance to water shortage by subjecting them to 3 water regimes (S0, irrigation at 100% of the field capacity (FC); S1, 50% FC; S2, 25% FC) for 90 days. Several variables were measured (stem growth, leaf area, trichome and stomatal density and size, gas exchange, and chlorophyll concentration). The moisture deficit caused a decrease in ecophysiological variables and an increase in stomata and trichomes density. Intraspecific variability was recorded. EF and BM plants showed a higher phenotypic plasticity index than OZ plants. The better flexibility towards hydric stress was reflected in the EF plants by an increase of the intrinsic water use efficiency (WUEint) converted into a more sustained stem growth. In the overall context of global warming and of Mediterranean forests fragility, the success of new afforestation of Q. suber requires the selection of the best adapted provenances to low water availability, such as the EF provenance. [Translated by Editor.]
显示更多 [+] 显示较少 [-]