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sur le développement des zones arides et semi-arides

  World’s First ’Self-Watering’ Desert Plant : Desert Rhubarb

  ScienceDaily (July , 2009)

• ScienceDaily (July 5, 2009) - Researchers from the Department of Science Education-Biology at the University of Haifa-Oranim have managed to make out the "self-irrigating" mechanism of the desert rhubarb, which enables it to harvest 16 times the amount of water than otherwise expected for a plant in this region based on the quantities of rain in the desert. This is the first example of a self-irrigating desert plant, the scientists say.

• The desert rhubarb grows in the mountains of Israel’s Negev desert, where average precipitation is particularly low (75 mm per year). Unlike most of the other desert plant species, which have small leaves so as to minimize moisture loss, this plant is unique in that its leaves are particularly large ; each plant’s rosette of one to four leaves reaches a total diameter of up to one meter.

• The results of experiments and analysis of the plant’s growth - in an area with an average annual rainfall of 75 mm - showed that the desert rhubarb is able to harvest quantities of water that are closer to that of Mediterranean plants, reaching up to 426 mm per year. This is 16 times the amount of water harvested by the small-leafed plants of the Negev desert region. When the research team watered the plant artificially, they observed how the water flows along the course of the leave’s depressed veins to the ground surrounding the plant’s single root and then penetrates the ground to a depth of 10 cm or more. Under the experimental conditions, water penetrated the ground only as deep as 1 cm.

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