The main response of natural Aleppo pine trees to drought has been studied in three sites on the North-western of Tunisia, in order to assess their capacity to adapt to climate change and overcome the water challenge. This research was based on the evaluation of some physiological traits (xylem conductivity, water potential..), the soil moisture, the water content, and the foliar gas exchange (photosynthesis, transpiration, and stomatal conductance).
Aleppo pine (Pinus halepensis Mill.) is one of the most drought-tolerant pine species and it is distributed over large drought-prone Mediterranean regions. The determination of the water balance of the soil-crop-climate and its fluctuation is difficult to achieve, due to the spatial variation in site conditions (Schiller and Cohen, 1998). The objectives of this study are to (1) estimate crop water requirements (ETc) and actual evapotranspiration (ETa) of Tunisian Aleppo pine and (2) study the impact of climate change on water balance, using the WEAP-MABIA Module (Yates et al.,2005a; 2005b; Jabloun and Sahli, 2012) based on the FAO Irrigation and Drainage publication 56 (Allen et al., 1998).