Pecan trees are natives of the eastern deciduous forests, far from the Chihuahuan Desert. Yet, the Southwest is a major producer of pecans. In New Mexico in 1999, almost 30,000 acres of pecan groves produced some 50 million pounds of nuts.
So, if pecan trees do so well here, why aren't they native? As in regard to so many things in our desert, the answer is water. Pecans thrive here because, and only because, of irrigation. Sufficient water, along with the hot, clear days and geographic isolation from various pest organisms, make the Southwest an important region for pecan growing.
On a larger geographic and chronologic scale, forests once spanned the
North American continent. Through time, forested areas in the Southwest and
mid-continent became drier and drier. Trees requiring high moisture levels disappeared,
followed eventually by those requiring lesser and lesser amounts. In time, virtually
all were extirpated, leaving only grasslands and deserts separating the forests of the
East from those of the Far West--and nary a pecan tree within hundreds of miles of our
desert.
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.