As everyone in the desert knows, water rules. Not only does human life in the desert depend on the availability of water, but so does the life of every other organism. Most animals can travel to water if necessary. Plants, however, are stuck in place, and either have to reach out for moisture with their roots or wait for water to come to them.
Many desert plants can't survive on the amount of precipitation
falling on them, yet do quite well, thank you. These plants depend on the inequalities
of water distribution to get more than their share. In any rain heavy enough to run
off, the higher terrain necessarily donates its just portion to the hollows and
drainage ways. Thus a Desert Willow growing at the edge of an arroyo bottom may be
enjoying many times the amount of water available just a few feet up slope. When you
gaze across a desert landscape, look at the patterns made by the plants. In large part,
what you see is merely mimicking the pattern of unequal water distribution.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.