Perfect adaptation to the local conditions is a common theme regarding organisms native to an area. Thus we are urged to plant native because these plants are the best possible for local conditions. In fact, though, we'd be more realistic if, and only if, we changed "best adapted" to just "adapted". Obviously our native desert plants are fit for our climate, soils, and general ecology. Otherwise, they would not have survived here. But this really translates to them being "well enough" adapted, not necessarily "best adapted'.
Why not considered best adapted? Well, for one thing, many non-natives
do very nicely when introduced, often even displacing natives. The saga of Salt Cedar
in the Southwest is well known as it chokes riversides at the expense of native plants
and wildlife. On the other hand, ornamentals from other arid regions form major
constituents of many gardens and may even escape into the desert. The South American
Yellow Bird of Paradise is a well-known example. But the bottom line? Plant and enjoy
our native plants--after all, they are "well enough" adapted.
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.