The appearance of invasive species is a major worry. Successful species from elsewhere often choke out native organisms and may cause major damage in other ways, as we've seen with the introduced West Nile Virus that causes disease in birds and humans or with the pipe-clogging Zebra Mussel.
We occasionally hear people suggesting that it's not really a big
deal because animals and plants have always moved around, invading new areas. Although
this is true, there are major differences between natural invasions and the current
situation. We've managed to speed up the process of exchanging organisms between
and within continents far beyond the natural pace. As a result, many natural
communities are being hit by a variety of alien species, overwhelming faunas and floras
that could adapt to newcomers slowly entering one by one. Locally, even such a simple
plant as the domestic morning glory can cause economic damage. Ask our farmers whose
cotton plants make natural trellises for the climbing vines, and believe me, the terms
used for the invaders do not include the word glory!
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.