One of the characteristics of the desert, of course, is its low productivity of animal and plant material. With the surge in population during the past few centuries, desert dwellers have become at the mercy of the non-arid regions of the world for food and other agricultural products. Now, because of this, some of the more arrogant regions of the world might consider us parasites. But we have a comeback—so are they!
The oxygen we breath is produced during photosynthesis when carbon
dioxide is broken apart for its carbon. Obviously, the desert doesn't have enough
vegetation to supply all the oxygen its biota needs but neither do most other
terrestrial habitats. About half of all oxygen produced by photosynthesis is from
single celled organisms living in the upper levels of the oceans. Doesn't do too
much for the ego, does it, to realize how dependent we are on beings almost invisible
to the naked eye. But there is one bright spot—even the most arrogant regions are at
the mercy of some of the simplest organisms on earth.
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.
References
Fuhrman, J. 2003. Genome sequences from the sea. Nature, 424:1001- 1002.